Along-strike variations in recent tectonic activity in the Santander Massif: New insights on landscape evolution in the Northern Andes

Journal Pre-proof Along-strike variations in recent tectonic activity in the Santander Massif: New insights on landscape evolution in the Northern Andes Helbert García-Delgado, Silvia Machuca, Francisco Velandia, Franck Audemard PII:

S0895-9811(19)30293-7

DOI:

https://doi.org/10.1016/j.jsames.2019.102472

Reference:

SAMES 102472

To appear in:

Journal of South American Earth Sciences

Received Date: 17 June 2019 Revised Date:

16 December 2019

Accepted Date: 17 December 2019

Please cite this article as: García-Delgado, H., Machuca, S., Velandia, F., Audemard, F., Along-strike variations in recent tectonic activity in the Santander Massif: New insights on landscape evolution in the Northern Andes, Journal of South American Earth Sciences (2020), doi: https://doi.org/10.1016/ j.jsames.2019.102472. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Ltd.

Along-strike variations in recent tectonic activity in the Santander Massif: new insights

1

on landscape evolution in the Northern Andes

2

a, 1, *

Helbert García-Delgado

3

; Silvia Machuca

a, 2

b, 3

; Francisco Velandia

c, 4

; Franck Audemard

4

a

Servicio Geológico Colombiano, Bogotá, Colombia

5

b

Universidad Industrial de Santander, Bucaramanga, Colombia

6

c

Fundación Venezolana de Investigaciones Sismológicas (FUNVISIS), Caracas, Venezuela

7

1

E-mail address: [email protected]

8

2

E-mail address: [email protected]

9

3

E-mail address: [email protected]; [email protected]

10

4

E-mail address: [email protected]

11

*Corresponding author.

12

E-mail address: [email protected], [email protected] (H. García-Delgado)

13

Abstract

14

Integration of drainage analysis and topographic metrics provide excellent tools to assess the

15

Quaternary tectonic activity modeling landscape evolution in evolving orogens. Furthermore,

16

detecting active structures through the geomorphological analysis of landscapes helps to identify

17

potentially seismogenic structures that could impact the socio-economic conditions in developing

18

countries. Therefore, this paper presents a tectonic geomorphology study conducted on the

19

Santander Massif (SM, Colombian Eastern Cordillera) and surrounding areas. The SM has

20

structures with reported Quaternary activity such as the Bucaramanga, Morro Negro-Las Mercedes,

21

and Chitagá faults, which summed to a poorly-constrained paleosismological history with significant

22

shallow events is the prime incentive of this work. Our study is based on the acquisition of

23

topographic data through swath profiles, local relief, slope variability, filtered topography, minimum

24

bulk erosion, which along with geomorphic indices like the normalized concavity steepness (ksn), the

25

hypsometric integral (HI), the ratio valley floor width to valley height (Vf) and normalized river

26

profiles provided new insights on the recent landscape evolution in this part of the Northern Andes.

27

We compared published apatite fission tracks (AFT) data for the study area with the uplift pattern

28

deciphered from the geomorphic indices to detect the consistency in exhumation and denudation

29

processes both in the long and short-term. Consequently, the central SM, as well as the faulted

30

block between the Bucaramanga and Guamalito faults, evidence a highly-incised landscape with

31

local relief values exceeding the 1500 m, then, responding with a sharp incision to recent surface

32

uplift. Interestingly, this uplift pattern in central SM matches with published AFT data and is related

1

33

to Neogene exhumation events controlled by secondary structures like the Suratá Fault. We

34

attribute this exhumation event, and accelerated denudation rates within the SM, to the influence

35

exerted by the “collision” between the SM and the Pamplona Indenter, leading to the unroofing of

36

basement rocks at the deformation front (e.g., the Vetas High) and the topographic building of the

37

range.

38

For the upthrown block (hanging wall) of the Bucaramanga Fault, the occurrence of poorly-graded

39

river profiles with an average concavity factor of 12.01, as well as irregular hypsometric curves with

40

convex lower reaches, reinforce the hypothesis that late Cenozoic topographic rejuvenation in the

41

SM was also forced by the tectonic activity of the Bucaramanga Fault. We expect empirical uplift

42

rates > 0.08 mm/yr (very high to high tectonic activity) for the mountain front encompassed between

43

La Esperanza and Bucaramanga localities. We state this assumption since the mountain front

44

delimited by the structure mentioned above is quite straight, it preserves remarkable

45

morphostructural features and displays V-shaped valleys with an average Vf index of 0.38. This

46

uplift rate is in good agreement with recent thermochronological exhumation rates (0.1 to > 0.3

47

mm/yr) published by Siravo et al. (2019).

48

Higher uplift rates associated with the Bucaramanga Fault were also constrained with the erosion

49

proxy index, i.e., the ksn index. High ksn values (above 128) were observed following a linear pattern,

50

which in turn seems controlled by the main trace of the Bucaramanga Fault. For instance, the river

51

system draining the western piedmont of the SM, near Aguachica, records slope-break knickpoints

52

that we interpret as evidence of an incisional wave migrating upstream and adjusting a late

53

Neogene uplift event associated with the Bucaramanga Fault. Conversely, the northern SM

54

presents variable tectonic activity with the inner part, east of the Guamalito Fault, presenting low

55

tectonic activity with little surface uplift and dominant strike-slip kinematics. We recognize the

56

Ocaña-Ábrego zone as a relict landscape with well-preserved non-consolidated deposits that may

57

record the initial exhumation and denudational pulses of the SM during the Andean Orogeny.

58

Keywords: Bucaramanga fault, Berlin plateau, Mérida Andes, tectonic geomorphology, Quaternary

59

1. Introduction

60

Present-day active tectonic studies relate to the processes that shape the landscape and its impact

61

on human society (Keller and Pinter, 2002). The inexorable struggle between tectonic processes

62

that tend to build topography, and surface processes (including the action of climate) that tend to

63

tear them down, are the primary basis of tectonic geomorphology studies (Burbank and Anderson,

64

2012). Active tectonics researches at the regional scale are interested in understanding surface

65

uplift following folding and movements along individual faults, which in turn provides valuable

66

information on ground rupture processes and seismic hazard assessment (Burbank and Anderson,

67

2012; Keller and Pinter, 2002). Surface uplift pulses induce fast erosion responses from the

2

68

landscape in the form of channel incision, drainage reorganization (e.g., stream piracy, drainage

69

diversion) as well as basin rejuvenation (Bishop, 1995; Burbank and Anderson, 2012; Kirby and

70

Whipple, 2012). However, high erosion rates and denudation processes shaping landscape are

71

also forced by geological factors (such as lithological strength) or climatic factors (such as

72

enhanced orographic precipitation), that must be considered when interpreting geomorphic

73

processes (Cederbom et al., 2004; Whipple, 2009; Willett, 1999).

74

In the complex competition between tectonics and denudational processes, both the drainage

75

network and topography are sensitive to record any disturbance deviating the “normal” landscape

76

evolution in a steady-state (dynamic equilibrium) to a transient state (Burbank and Anderson, 2012).

77

In a transient state, the complex interactions among surface uplift, climate, channel geometry, and

78

surrounding hillslopes dictate how fast the landscape is adjusted to an external disturbance. As a

79

specific landscape is being affected by surface uplift, the drainage system and surrounding

80

hillslopes response with steepening and increased erosion rates in order to compensate surface

81

uplift (e.g., Burbank et al., 1996). Considering this, the quantitative and qualitative analysis of the

82

drainage network and drainage basins can give some worthwhile insights into the recent landscape

83

evolution of a particular area and its drivers. The quantitative approach has been proved to be a

84

valuable tool to characterize areas deformed by active structures in a timescale ranging from 10 to

85

10 years (Azañón et al., 2015; Keller and Pinter, 2002; Kothyari et al., 2017; Pérez-Peña et al.,

86

2010). Furthermore, in landscapes where deformation is partitioned into strike-slip and pure-shear

87

components (dictated by a transpressional stress state) such as the Colombian Eastern Cordillera

88

(Jiménez et al., 2014; Taboada et al., 2000), the most significant product is observed in topographic

89

relief and crustal thickening that in turn is essential in mountain-building processes (Tikoff and

90

Teyssier, 1994).

91

In this work, we explore the Quaternary tectonic activity related to major structures in the Santander

92

Massif (SM), the northern part of the Colombian Eastern Cordillera, with a particular focus on the

93

striking Bucaramanga Fault. Besides the SM is a crucial range to decipher the complex

94

Phanerozoic tectonic evolution of the Northern Andes, this area also has structures with reported

95

Quaternary activity such as the Bucaramanga, Morro Negro-Las Mercedes and Chitagá faults (e.g.,

96

Paris and Romero, 1994; Paris et al., 2000; Diederix et al., 2009), which summed to a poorly-

97

constrained paleosismological history with significant shallow events (e.g., Arboledas July 8, 1950,

98

Ms=6.7), are the basis for this investigation. Thus, we attempt to identify and provide new

99

topographic evidence of active structures that could behave seismogenically and be responsible for

100

the historical earthquakes reported within the range. We also explore the influence of these active

101

structures in the recent landscape evolution of the SM. To accomplish our goal, we implemented a

102

quantitative geomorphological analysis by using several topography-related metrics such as

103

regional swath profiles, local relief, slope variability, and minimum bulk erosion. We complemented

104

this analysis with normalized longitudinal profiles (Demoulin, 1998) and some geomorphic indices

3

5

3

105

such as the concavity steepness (ksn), the hypsometric integral (HI), the ratio of valley floor width to

106

valley height (Vf) and the drainage basin shape index (Bs).

107

The SM is an igneous-metamorphic core complex (Cediel et al., 2003) that extends for about

108

16,000 km . The SM shows variations in topography because of its structural evolution as part of

109

the Maracaibo Block (Taboada et al., 2000; Audemard and Audemard, 2002; Cediel et al., 2003),

110

which links the Eastern Cordillera of Colombia, the Mérida Andes and the Serranía de Perijá

111

(Northern Andes, Fig. 1). Deformation across the Santander Massif and surrounding areas have

112

been characterized by longitudinal strike-slip structures that behave as major tectonic boundaries

113

(Acosta et al., 2007; Cediel et al., 2003; Kammer, 1999; Sarmiento-Rojas et al., 2006; Taboada et

114

al., 2000; Velandia, 2005). The most conspicuous structure in the SM and turn, the southwestern

115

border of the Maracaibo Block, is the Bucaramanga Fault. This fault trend NNE together with other

116

regional structures such as the Guamalito, Villa Caro, or Haca faults (Fig. 2), all of them as left-

117

lateral strike-slip faults. The regional kinematics is governed by the current displacement of the

118

Maracaibo Block and the more regional NE escape of the Northern Andes (Audemard, 1993; 1998,

119

2002, 2009; Egbue and Kellogg, 2010; Audemard, 2014; Mora-Páez et al., 2018). Besides major

120

longitudinal faults, secondary faults are common within the SM, mainly as transverse faults, but

121

under dominant right-lateral kinematics, (Velandia, 2017; Velandia and Bermúdez, 2018). Low-

122

temperature thermochronology data on the SM report several exhumation events, including the

123

Miocene-Pliocene (e.g., Mora et al., 2015; van der Lelij et al., 2016; Amaya et al., 2017, Velandia,

124

2017), and considering the SM as the hanging wall of the Bucaramanga Fault, Siravo et al. (2019)

125

related its exhumation mainly to vertical movement along the fault during the Neogene.

126

1.1 Previous studies in the SM

127

In terms of tectonic geomorphology in the Colombian Eastern Cordillera, most efforts have

128

essentially concentrated on studying active fault landforms (e.g., Paris and Romero, 1994; Paris et

129

al., 2000; Diederix et al., 2009; Velandia, 2017). Particularly, Oviedo-Reyes (2015) carried out an

130

interesting analysis along the Zulia Fault System, a splay of the Las Mercedes Fault, at the eastern

131

piedmont of the SM (Fig. 2). This author reports strath terraces and several geomorphic indices

132

(such as the concavity steepness, the hypsometric integral, the Hack’s index, among others) that

133

strongly support recent deformation associated with the mentioned fault system and its seismogenic

134

potential. In addition to this, a neotectonic and paleoseismological study conducted at the Cúcuta

135

zone provided new shreds of evidence about the recent tectonic activity in different structures within

136

the SM and its boundaries, especially along NE-SW trending structures as the Aguas Calientes

137

Fault (Rodríguez et al., 2018). Likewise, a paleosismological study of the Bucaramanga Fault

138

conducted by Diederix et al. (2009) nearby the Bucaramanga city led to the preliminary

139

identification of eight Holocene earthquakes with magnitudes ranging from 6.6 to 7.0 Ms and

140

spanning since 8300 to 930 yr/BP. In this context, it is worth highlighting that historical seismicity

2

4

141

within the SM comprises several destructive events like those reported in Pamplona (January 16,

142

1644; Mw = 6.9), Cúcuta (May 18, 1875; Mw = 7.0), Arboledas (July 8, 1950; Ms = 6.7) and Ocaña

143

(June 16, 1961; Ms = 6.5) (Cifuentes and Sarabia, 2009, 2007a, 2007b, 2006; Rodríguez et al.,

144

2018).

145

2. Regional setting

146

2.1 Geomorphological and climatic framework

147

The study area comprises three different landscapes where each one has different

148

geomorphological and climatic characteristics: (i) the mountainous area of the central SM where the

149

highest elevations are observed (Vetas High and Páramo de Guerrero, Fig. 1); (ii) the northern SM

150

between Ábrego and Guamalito with mean elevations of about 1300 m; and (iii) the Middle

151

Magdalena Valley Basin (MMV) to the west. The MMV can be subdivided into a flat area to the

152

north of La Esperanza and a low topography area between La Esperanza and Bucaramanga with

153

elevations ranging from 500-900 m (Fig. 1). Due to the high elevation of the Berlín Plateau and

154

surrounding areas, this landscape was affected by the maximum glaciation in the Colombian

155

Andes, which pre-dated the Last Glacial Maximum (Helmens, 2004). During this time, glaciers were

156

typical along the EC on elevations above 3000 m (Andriessen et al., 1993; Van der Hammen and

157

Hooghiemstra, 1996), leaving behind some remarkable glacial features as morainic deposits, U-

158

shaped and hanging valleys. The transition zone from the highest elevations of the central SM to

159

the lowlands of the Bucaramanga area is dominated by deep V-shaped valleys, especially those of

160

the Tona, Suratá and Frío rivers (Fig. 1). The Bucaramanga city is located on the lowest

161

topographic areas west of the Berlín Plateau, emplaced in an isolated block composed of

162

Quaternary thick fluvio-alluvial deposits of the informal Bucaramanga Formation (De Porta, 1959;

163

Jiménez et al., 2015). This unit is composed of a thick succession of conglomeratic to sandy beds

164

with well-rounded pebbles and subordinate muddy beds (De Porta, 1959), which has been recently

165

affected by erosion processes forming the so-called estoraques (i.e., hoodoos). These erosion

166

processes and geomorphic features are also observable at the Ocaña-Ábrego zone, where

167

badlands have developed on the thick Miocene to Pliocene (?) conglomeratic deposits of the

168

informal Algodonal Formation (Arias and Vargas, 1978).

169

The drainage network within these three vast landscapes also differs from one another, with most of

170

the drainages are tributaries of the MMV. From the central SM the drainage system is distributed to

171

the northern Catatumbo Basin through the Cucutilla, Sulasquilla and Pamplonita rivers; to the

172

Llanos Basin through the Cáraba and Chitagá rivers and to the MMV through the Suratá, Cáchira,

173

Negro and Lebrija rivers (Fig. 1). At the highest elevations within the central SM, the drainage

174

system is perpendicular to the structural grain, while to the north, there are transverse and

175

longitudinal rivers (e.g., Algodonal River, Fig. 1).

5

176

Regarding the climatic setting, an effective orographic barrier has been onset because of the

177

topographic building of the SM during the Neogene (Amaya et al., 2017). The orographic enhanced

178

precipitation pattern has resulted from just 2 km in elevation in the Alps (Willett, 1999) and about

179

1.3 km in the Central Andes (Bookhagen and Burbank, 2006). The SM easily exceeds 2 km in

180

elevation, especially at the central SM (Between Cáchira and Berlín plateaus, Fig. 1). Accordingly,

181

both flanks of the range trap the moist air masses coming from the Magdalena Valley to the west,

182

and the Táchira-Cúcuta area to the east (IDEAM, 2015), inducing a wetter climate on both sides

183

and a drier climate at the top of the SM where most of the moisture has been lost. This orographic

184

barrier is slightly asymmetrical because it produces about 4000 to 4200 mm/yr of precipitation in the

185

eastern foothills of the SM in the transition to the Catatumbo Basin while to the western foothills the

186

rainfall values vary between 3700-4000 mm/yr (Zones C1 and S1, Fig. 3). Therefore, the axial

187

zones of the SM have the lowest rainfall values of the study area, ranging from 200 to 700 mm/yr at

188

the Berlín Plateau and from 800 to 1300 mm/yr at the Ocañá-Ábrego zone (Fig. 3).

189

2.2 Geological framework of the study area

190

The SM and surrounding areas are part of a composite zone where three main regional tectono-

191

stratigraphic blocks interact: The Eastern Cordillera of Colombia, the Mérida Andes, and the

192

Serranía de Perijá (Fig. 1). In a sensu stricto, the SM is bounded by the Bucaramanga Fault to the

193

west (Ward et al., 1973), the Mutiscua-Las Mercedes Fault System (MMFS) to the east, the Rio

194

Servitá Fault to the south and the Haca Fault to the north (Fig. 2), this later separating the strike-slip

195

regime of the SM from the compressive regime of the Serranía de Perijá (Velandia, 2017). The

196

study area comprises the central-northern zones of the SM, the frontal deformation zone of the

197

Pamplona Indenter (Boinet et al., 1985), and some areas of the Middle Magdalena Valley Basin

198

(MMV) located to the west of the Bucaramanga Fault (Fig. 2).

199

The tectonic framework in the study area is dominated by a transpressive stress state induced by

200

wrenching along longitudinal faults (Kammer, 1999; Taboada et al., 2000) such as the

201

Bucaramanga and Guamalito faults (Fig. 2). Secondary transverse structures (NE-SW faults, e.g.,

202

Río Cucutilla and Suratá faults, Fig. 2) are located within tectonic domains bounded by longitudinal

203

faults in a domino-style faulting pattern (Velandia, 2017). These inner secondary fault systems show

204

oblique contraction kinematics, and they have been associated with Neogene exhumation events at

205

the central SM (Amaya et al., 2017). Longitudinal structures within the SM (N-S trending faults) as

206

the MMFS marks the eastern border of this tectonic domain. As the Río Servitá Fault, the MMFS

207

corresponds to an inversion structure of the former Jurassic-Early Cretaceous half-rift basin that

208

was separated into the Magdalena-Tablazo and Cocuy subbasins by the so-called Santander High

209

(Cooper et al., 1995; Sarmiento-Rojas et al., 2006). Because of the tectonic inversion process

210

during the Andean Orogeny (Mora et al., 2006), basement rocks and sedimentary sequences of the

211

Paleozoic and Jurassic crop out in the hanging wall of the MMFS, overthrusting the Cretaceous and

6

212

Paleogene units of the footwall (Fig. 2). The structural style of the eastern border of the SM along

213

the MMFS is controlled and segmented by the Río Cucutilla Fault (Fig. 2). To the north, the MMFS

214

is known as the Las Mercedes Fault that behaves as a thrust fault, while to the south, the Mutiscua

215

Fault with reverse kinematics dominates the system (Fig. 2).

216

Regarding the main strike-slip faults of the SM, the Bucaramanga Fault has been shown as one of

217

the major structures of the Eastern Cordillera and recognized as an active sinistral fault (Fig. 2),

218

especially by its morphological features (París et al., 2000; Diederix et al., 2009; Jiménez et al.,

219

2015; Velandia and Bermúdez, 2018). Together with the Bucaramanga Fault, the parallel

220

longitudinal faults of the Guamalito (to the NE) and the Lebrija fault (to the SW), constitute a

221

regional positive flower structure (Velandia, 2017). Between the major longitudinal faults, transverse

222

dextral faults are identified and interpreted as minor inner structures of a regional domino-style, the

223

same model that also explains deformation of the area of the Villa Caro and Haca faults, toward the

224

northern part of the SM (Velandia, 2017). Also, as a product of the tectonic evolution, the Vetas

225

High is interpreted by Velandia (2017) as a pop-up structure formed because of the influence

226

exerted by the Pamplona Wedge in the central SM (Fig. 1).

227

Besides the SM, the Pamplona Wedge, or “Indenter” in the sense of Boinet et al. (1985), is the

228

second large domain in the study area (Fig. 2). Reverse faults structurally characterize this domain

229

at the deformation front (e.g., Morro Negro Fault, Fig. 2) and strike-slip faults at the edges (southern

230

termination of the Boconó Fault, Fig. 2). This geometric array led to Boinet et al. (1985) to propose

231

an indentation mechanism to explain the arcuate shape of the structures and the tectono-

232

stratigraphic differences between the SM and the Pamplona area. Within the Pamplona Indenter,

233

the east-verging Labateca Fault, one of the most conspicuous structure bounding the Labateca

234

Block (Fig. 2), has been interpreted as a normal fault (Boinet et al., 1982), a footwall short cut of the

235

Servitá Fault (Corredor, 2003), or a back-thrust fault of the Pamplona deformation front (Velandia,

236

2017). The northern border of the Pamplona Indenter has been associated with the southern

237

prolongation of the Boconó Fault that Audemard and Audemard (2002) refer to as a transpressive

238

horse-tail termination.

239

Recent thermochronological studies of the SM have proposed that exhumation along the

240

Bucaramanga Fault was onset during the Eocene with the maximum rates reported during the

241

Andean Orogeny in Miocene times. (Amaya et al., 2017; van der Lelij et al., 2016). This later uplift-

242

related exhumation event was mostly controlled by inner structures within the SM. Meanwhile,

243

recent low-temperature thermochronology data in the Pamplona Wedge, have proposed that the

244

Labateca block exhumation began in Miocene-Pliocene times (Mora et al., 2015). Both, the Chitagá

245

and Labateca faults are the boundary of the so-called Labateca Block (Mérida Andes domain, Fig.

246

2), where a thick tabular sedimentary sequence spanning since Paleozoic to Cretaceous times are

247

exposed.

7

248

3. Geomorphic indices

249

The present study of the SM was conducted using a 30 m resolution DEM obtained from the ALOS

250

sensor (https://www.eorc.jaxa.jp/ALOS/en/aw3d30/index.htm). Koukouvelas et al. (2018) recently

251

compared the SRTM90, SRTM30, ASTER, and ALOS DEMs by obtaining several geomorphic

252

indices, suggesting this later is more accurate for tectonic geomorphology analysis. From this DEM,

253

the drainage network was extracted by using a D8 flow routine and by considering an accumulation

254

area of 1x106 m2. Then, we calculated the drainage network and 57 drainage basins (Fig. 3) by

255

using the Topographic Analysis Kit (Forte and Whipple, 2018) integrated with the TopoToolbox

256

codes for Matlab (Schwanghart and Scherler, 2014).

257

3.1 Swath profiles

258

The swath profiles are plots of elevations within an observation window or swath that are useful in

259

geomorphic studies because they avoid the subjective location of traditional cross-sections and

260

provide valuable information about tectonic uplift, faulting, river processes, among others (Telbisz et

261

al., 2013; Pérez-Peña et al., 2017). In recent times, swath profiles have become a valuable tool for

262

analyzing long-term landscape evolution, especially in mountainous areas where highly dissected

263

landscapes exposed to active incision/uplifting processes are typical (e.g., Molin et al., 2012;

264

Andreani et al., 2014; Godard et al., 2014; Scotti et al., 2014; Azañón et al., 2015; Calzolari et al.,

265

2016; Cheng et al., 2018). In this work, we calculated seven swath profiles by using the

266

SwathProfiler add-in provided by Pérez-Peña et al. (2017). Six profiles are perpendicular to major

267

structures, especially the Bucaramanga Fault System and the regional trend of the mountainous

268

area (Santander Massif), and one general profile (SP-G) is oriented NW-SE to observe along-strike

269

base-level changes (see Fig. 1 for location). The ArcGIS add-in calculates by default 50 lines

270

parallel to the baseline and extracts elevation points by using a sampling step-size of 1.5 times the

271

cell size of the DEM (Pérez-Peña et al., 2017). Every single transverse swath profile calculated in

272

this work has a length of about 90 km, and a width of 10 km while the SP-G swath is ~ 230 km in

273

length and 20 km width. Besides the maximum, minimum, and mean topographic elevations for

274

each swath, we extracted the local relief and the enhanced transverse hypsometry index (THi*).

275

The THi* is a modified index obtained from weighting the HI values with the relative local relief to

276

avoid significant differences in HI values calculated from swath profiles (Pérez-Peña et al., 2017).

277

3.2 Topographic analysis along the study area

278

Local relief maps of a specific area are an indicative morphometric parameter reflecting incision

279

states that could be associated with active tectonics (Molin et al., 2004). Relief maps can be

280

calculated subtracting the altitude difference (hmax-hmin) based on focal statistics within a square

281

moving window of 5x5 km. This window width should represent the typical valley width, and

282

therefore, this parameter is variable for different study areas. Besides the relief map, we obtained

8

283

the slope variability map (Ruszkiczay-Rüdiger et al., 2009; Matoš et al., 2016), which refers to the

284

difference between the minimum and maximum slope. As with the relief map, we used the focal

285

statistics tool package from ArcGIS and performed the index calculation with a square moving

286

window of 5x5 km.

287

Some authors have used a topographic filtering by implementing cut-off wavelengths ranging from 5

288

km up to 300 km to detect different topographic signals influenced by tectonics such as regional

289

surface dipping towards a preferred direction (e.g., Calzolari et al., 2016; Ghisetti et al., 2016) or

290

elastic flexure of the lithosphere (e.g., Faccenna et al., 2011; Molin et al., 2004, 2012). The filtered

291

topography (Molin et al., 2004) of the study area was obtained by passing a low-pass filter with the

292

Focal Statistics tool of ESRI ArcGIS for two different cut-off wavelengths oriented to discern

293

between crustal tectonics (10 km) and mantle dynamics (50 km). In the long-wavelength analysis,

294

we used 50 km as a cut-off value because crustal thickness along the study area has been

295

estimated in a range between 40-50 km (Yarce et al., 2014; Mora-Páez et al., 2016). Both the 10

296

km and 50 km low-pass filters were applied to a larger DEM to avoid edge effects (e.g., Ghisetti et

297

al., 2016).

298

3.3 Minimum bulk erosion (Ebulk)

299

Long-term erosion at regional scales can be assessed by obtaining the volume difference between

300

a pre-incision surface of a study catchment and the modern topography (Bellin et al., 2014). The

301

pre-incision surface is created by interpolating the altitude from present-day lateral divides for every

302

single catchment (Bellin et al., 2014). The interpolation procedure and the computing of this pre-

303

incision surface were performed with the 3D analyst toolbox from ArcGIS. The “eroded volume”

304

must be considered as a minimum bulk erosion (Ebulk) value because it does not consider interfluve

305

erosion (e.g., Brocklehurst and Whipple, 2002; Menéndez et al., 2008). Analysis of Ebulk in recent

306

times has provided vital insights into recent surface uplift pulses and erosion patterns in different

307

tectonic settings (Menéndez et al., 2008; Pérez-Peña et al., 2010; Giaconia et al., 2012b; Azañón et

308

al., 2015; Gaidzik and Ramírez-Herrera, 2017). Under uniform lithological and climatic conditions,

309

high Ebulk values are indicative of active uplifting and dissection along a study catchment. The Ebulk

310

values of the 57 watersheds were normalized by the catchment area.

311

3.4 Watershed and drainage analysis along the study area

312

In order to quantify the short-term evolution of the study area, we carried out a drainage analysis

313

based on several geomorphic indices. River longitudinal profiles are presented as normalized

314

profiles (Demoulin, 1998), which are an optimal form to compare watersheds with different sizes,

315

besides observing the shape of the river and estimates whether equilibrium or transient states

316

dominates river processes. Normalized river profiles have been successfully applied to infer tectonic

317

influence on mountainous valleys (e.g., Demoulin, 1998; Molin et al., 2004; Ruszkiczay-Rüdiger et

9

318

al., 2009; Antón et al., 2014; Rossetti et al., 2017). These profiles were obtained using the NProfiler

319

ArcGIS add-in algorithm, and they were automatically smoothed with a factor of 2 to better

320

represent the river profile (Pérez-Peña et al., 2017). Besides, the concavity factor (Cf), the

321

maximum concavity (MaxC), and its position concerning river source (dL) are also obtained. The Cf

322

index is the area on the plot between the river profile and a straight line connecting the source and

323

outlet of the drainage basin; this index varies between 0.0 (0%) to 0.5 (100%), and high values are

324

indicative of concave profiles which represent graded rivers (Demoulin, 1998; Ruszkiczay-Rüdiger

325

et al., 2009).

326

In recent years the analysis of a stream power law that correlates the channel slope (S) with the

327

upstream contributing drainage area (A) has been successfully employed to recognize regional

328

patterns of tectonic uplift. The use of the normalized concavity steepness (ksn) has the main

329

objective to highlight any external driver deviating the river profile from an equilibrium state into a

330

transient state (Whipple and Tucker, 1999; Whipple, 2004; Wobus et al., 2006; Whittaker et al.,

331

2008; Kirby and Whipple, 2012). The ksn index responds to a power law as follows (Flint, 1974):
=   

332

Where θref is the reference concavity that often varies from 0.4 and 0.6 (Wobus et al., 2006), thus,

333

we normalized this index by using a θref = 0.45 as many other works (e.g., the Colombian Eastern

334

Cordillera, Struth et al., 2017), and a critical threshold drainage area of about 1x10 m . This index

335

was calculated with the TopoToolbox codes for Matlab (Schwanghart and Scherler, 2014).

336

The hypsometric integral (HI), an index obtained to quantify the hypsometric curve, is often used to

337

estimate the incision state of a given landscape (Strahler, 1952; Keller and Pinter, 2002). The

338

advantage of the HI index is that drainage basins of varied sizes can be compared as the

339

hypsometric curve is plotted as a function of total area and total elevation (Keller and Pinter, 2002).

340

The HI can be calculated as follows:

7

2

=   −  /  −  

341

High values of the HI index (convex curves, HI>0.5) suggest a highly-incised drainage basin,

342

intermediate values (S-shaped curves, 0.4
343

values (concave curves, HI<0.4) are related to poorly-incised basins where erosion dominates over

344

tectonic processes (El Hamdouni et al., 2008; Menéndez et al., 2008; Pérez-Peña et al., 2010;

345

Giaconia et al., 2012a; Kothyari et al., 2016). In some cases, the hypsometric curve deviates from

346

previous shapes and presents small convexities that some authors have associated with the

347

rejuvenation of the drainage basin because of recent uplift or piracy events (El Hamdouni et al.,

348

2008; Giaconia et al., 2012b). Small convexities along hypsometric curves could represent poorly

349

eroded areas associated not only to tectonic influence and basin rejuvenation but to lithological

10

350

contacts and competent bedrock. The HI index for each drainage basin was calculated with the aim

351

of the Topographic Analysis Kit (Forte and Whipple, 2018).

352

The ratio of valley floor width to valley height (Vf) is a useful geomorphic index that has been used

353

to better constraint incision patterns (Bull and McFadden, 1977). This index is helpful to differentiate

354

between “V” shaped valleys where an active incision is undergoing and “U” shaped valleys. Low Vf

355

values are characteristic of “V” shaped-valleys while high Vf values are more related to “U” shaped-

356

valleys (Keller and Pinter, 2002; Silva et al., 2003; El Hamdouni et al., 2008; Pérez-Peña et al.,

357

2010). The Vf index can be calculated as follows:  = 2!/"#$ − #%& + #($ − #%&)

358

where Vfw is the valley width, Eld and Erd are the elevations of the left and right flank of the valley,

359

respectively, and Esc is the elevation of the valley floor. Finally, we explored the drainage basin

360

shape index (Bs), which is a useful index to differentiate between elongated basins and more

361

circular basins (Cannon, 1976; El Hamdouni et al., 2008). In tectonically active mountains subjected

362

to surface uplift, drainage basins tend to show an elongated and steeped landscape while in low

363

tectonic activity settings, erosion produces drainage basin widening (Ramírez-Herrera, 1998). The

364

Bs index can be calculated as follows: *% = */*!

365

where Bl is the length of the drainage basin measured from the divide to the outlet, and Bw is the

366

width of the drainage basin at its widest section.

367

4. Results

368

4.1 Topographic analysis

369

The SP-G oriented NW-SE cuts the study area along the Guamalito, Ocaña, Ábrego, Cáchira, and

370

Berlin zones (Fig. 4). The profile is characterized by an increase in topography towards SE, where

371

the highest altitudes are observed (~ 4500 m, Fig. 4). From NW to SE, minimum topography is

372

associated with the Catatumbo River that drains to the Catatumbo Basin, the Cáchira, and Suratá

373

valleys draining into the Magdalena Basin and the Cáraba valley which drains to the Llanos Basin.

374

Between Guamalito and Ábrego, the mean elevation ranges from 900 to 1600 m, while the highest

375

altitudes remain constant along this segment with values ranging from 2400 to 1500 m. To the

376

south of Ábrego, there is an increase in topography with the mean elevation topography passing

377

from 2200 (valley of the Cáchira river) up to 3800 m. Local relief increases progressively from

378

Ábrego to the SW up to ~2350 m at the Páramo de Guerrero, the upper catchment of the Cáchira

379

river (Fig. 4). The southern segment of the profile is dominated by a high elevation low relief area of

380

the so-called Páramo de Berlin or “Berlín Plateau”. The Berlin Plateau has a mean topography of

381

about 3200 m with a local relief ranging from 900 to 1600 m (Fig. 4).

11

382

Transverse NE-SW oriented profiles show several differences along the strike of the Bucaramanga

383

Fault (1) and the western Santander Massif. The SP1 profile crosses from SE to NW, the MMV, the

384

Filo Jaramillo, and the low topography areas draining to the east into the Catatumbo Basin (Fig.

385

5a). Topography rapidly increases from the MMV from 200 m up to ~2150 m at the Filo Jaramillo;

386

this increase in topography matches well with an increase in local relief up to 1200 m. Just to the

387

east of the Guamalito Fault (16) area, the mean topography remains constant at ~1300 m while

388

local relief decreases up to 200 m. At the eastern segment of the SP1 profile, mean topography

389

decreases rapidly, ranging from ~400 to 800 m; however, local relief increases up to ~1450 m with

390

higher values than observed along the hanging wall of the Bucaramanga Fault (1).

391

Along the SP2 profile (Fig. 5b), topography varies drastically from west to east, passing from the

392

low-altitude, low-relief MMV basin to the medium-high topography and low-relief area of the Ocaña-

393

Ábrego zone and the eastern boundary of the Santander Massif. On the hanging wall of the

394

Bucaramanga Fault (1), between Aguachica and Ocaña, there is an increase in local relief up to

395

~1050 m; however, it rapidly decreases at the Ábrego zone with a relief value of ~120 m. To the

396

east, the increase in topography is associated with the positive flower structure between the Villa

397

Caro and Haca faults (15 and 17 in Fig. 5b). Minimum topography is associated with fault-controlled

398

drainage at the catchment of the Catatumbo River. Eastward of the Haca Fault (17) and the

399

hanging wall of the Las Mercedes Fault (14) is characterized by a decrease in maximum and mean

400

topography but with an increase in local topography up to ~1440 m, the highest value of the profile

401

(Fig. 5b).

402

Along the SP3 (Fig. 5c), two high topography areas are observed: between the MMV and the

403

Orocué ridge with a maximum topography of ~2660 m and between Ábrego and Filo El Romero (El

404

Romero ridge) with a maximum topography of ~2715 m (Fig. 5c). Eastward of the low relief Ábrego

405

zone, on the hanging wall of the Haca Fault (17), topography increases up to ~ 2700 m, with local

406

relief of 1500 m (Fig. 5c). The highest local relief values are obtained on the hanging wall of the Las

407

Mercedes Fault (1570 m), although topography decreases towards the Catatumbo basin.

408

The SP4 is characterized by a maximum topography of about 3700 m in elevation (Fig. 6a). A

409

metamorphic-cored uplifted block characterizes this area with Jurassic and Cretaceous sedimentary

410

remnants (Fig. 2) located at the maximum topographic areas (Cáchira high). On the eastern block

411

of the Bucaramanga Fault (1), local relief increases rapidly from 200 m to 900 m and a maximum

412

topography of about 1300 m. Between the Bucaramanga (1) and Guamalito (16) faults, maximum

413

topography increases from 1300 m up to ~2600 m while local relief increases up to 1200 m. The

414

highest local relief reaches ca. 1500 m and coincides with the eastern side of the Páramo de

415

Guerrero (Fig. 6a).

416

Along the SP5, we observe the northern remnants of the Berlín plateau, which is currently being

417

incised by the Negro River (increase in local relief, Fig. 6c). The most significant results are that the

12

418

influence of NE-SW faults becomes more critical. Between the MMV and the Bucaramanga (1) fault,

419

maximum topography varies from 300 m to 1200 m with a local relief value of about 900 m.

420

Between the Bucaramanga (1) and the Suratá (11) faults, topography increases; however, local

421

relief remains almost constant up to the hanging wall of the Suratá (11) Fault where local relief

422

increases up to 1300 m, and THi* surpasses 0.5 (Fig. 6b). At the Vetas High, local relief remains at

423

a value of around 1200 m; however, THi* values increase over 0.5 at the highest altitudes and the

424

eastern foothills, which suggests an active incising landscape. To the east, the influence of the

425

Morro Negro (8) fault and the front deformation zone of the Pamplona Indenter is observed with a

426

maximum topography of about 2900 m and an increase in local relief up to 1400 m (Fig. 6b).

427

Along the SP6 profile, between the Lebrija (12) and Bucaramanga (1) faults, there is a low

428

topography low relief area where the Bucaramanga city is emplaced. From the Bucaramanga city

429

(Fig. 1) to the east, maximum topography rapidly increases up to 3700 m at the Berlin plateau (Fig.

430

6c). The Berlin plateau is a high topography-low relief area (low THi* values, Fig. 6c) affected by

431

glacial erosion in the Quaternary. The Berlin plateau is bounded to the east-northeast by the Sevilla

432

(2) Fault, to the north by the Rio Charta Fault and to the southeast by the MMFS (Figs. 2 and 6c).

433

To the east of the SP6 profile, several local relief peaks, as well as an increase in THi* values,

434

suggest active incision activity (Fig. 6c). The highest local relief values obtained in the profile are in

435

the hanging wall of the Chitagá (4) Fault and within the Labateca block (Fig. 2), which is structurally

436

bounded by the Chinácota (7) and Labateca (6) faults (Fig. 6c). This zone represents the so-called

437

Pamplona indenter (Boinet et al. 1985) or Pamplona wedge sensu Velandia (2017), a fault-bounded

438

block representing the southern extension of the Mérida Andes. In the Pamplona indenter, within

439

the Labateca block, the Chitagá River has incised a deep canyon with the subsequent rise of the

440

local relief up to 2000 m (Fig. 6c).

441

Mean slope, slope variability, local relief, and integral hypsometry maps (Fig. 7) show some distinct

442

features highlighted before with the swath profiles. In the north, the Ocaña-Ábrego zone is

443

characterized by low-relief, low HI, and gentle slopes. The transition from this zone into the central

444

SM is marked by high values of local relief and slope variability (Fig. 7). To the southern areas, the

445

Berlín Plateau is observed in the local relief map as well as in the slope variability map (Fig. 7),

446

while the hypsometry map shows a moderately-eroded landscape that is under substantial incision

447

on its boundaries (Fig. 7).

448

Regarding the filtered topography, short-wavelength filtering (Fig. 8A) shows that the highest values

449

are constrained to the central-southeastern parts of the study area, particularly at the Páramo de

450

Guerrero and the transition zone between the Pamplona zone into the Mérida Andes (Fig. 1). On

451

the other hand, the central-northern zones are characterized by low values, supporting the above

452

interpretations based on local relief and hypsometry maps (Fig. 7). In the long-wavelength filtering

13

453

(Fig. 8B), the most exciting results are an anomaly zone observed in the southern boundaries of the

454

Berlín Plateau.

455

In terms of long-term erosion processes, we calculated an average normalized Ebulk of 151.37x10

456

m /km (Table 1). The most prominent average values were obtained for zones N1 and S2 with

457

average values of 161.34 x 10 m /km and 160.0310 m /km , respectively (Table 1). The highest

458

Ebulk values were obtained for basins B37 and B51 (Cáchira and Suratá rivers, Table 1) which are

459

two of the most essential drainage basins along the study area as they are in a critical zone where

460

longitudinal (NW-SE faults) and transverse (NE-SW faults) structures are acting and deforming the

461

central Santander Massif (Fig. 3).

462

4.2 Drainage analysis of the study watersheds

463

Normalized river profiles obtained from 20 selected watersheds along the study area (Fig. 3) are

464

presented in Figs. 9 and 10. To better represent drainage analysis, we divided the study area into

465

five zones (N1, N2, C1, S1, S2; Fig. 3). In the northern Zone N1, river profiles change from a more

466

concave profile (e.g., Basin B01, Fig. 9) to a straighter profile (e.g., B05, Fig. 9). At this zone, the

467

highest Cf value was calculated for watershed B01 (41.61%, Table 1). In zone N2, normalized

468

profiles tend to be straighter than in zone N1 (Fig. 9). There, we obtained an average Cf value of

469

33.70% with the highest and lowest values calculated for basins B10 and B19 (49.35% and

470

16.50%, respectively). Hypsometric curves in zone N1 vary from concave to irregular profiles (small

471

convexities at upper reaches) with HI values slightly increasing to the south from 0.35 to 0.54 (Table

472

1, Fig. 11). In zone N2, hypsometric curves are S-shaped with small irregularities at lower reaches

473

that could be associated with localized basin rejuvenation. An average HI value of 0.39 for basins in

474

zone N2 is indicative of a moderately-eroded landscape (Table 1).

475

In zone C1, river profiles show slightly concave profiles (Fig. 9) with an average Cf value of 20.92%

476

(Table 1). Hypsometric curves for zone C1 are concave to irregular with HI values ranging from 0.31

477

to 0.54 (Fig. 11, Table 1). It is worth noting that the lowest Cf values obtained in this area were for

478

basins B28 and B33 (-3.02 and -5.77, respectively), which show remarkably convex-shaped profiles

479

(Fig. 9).

480

In zone S1, we observed a slight increase in the average Cf value concerning zone C1, passing

481

from 20.92 to 23.70 (Table 1). The highest values of MaxC were obtained for larger watersheds as

482

the Suratá River (Basin B51, Fig. 10). As in zone C1, for zone S1, we obtained an anomalous

483

profile presenting a negative Cf of -3.81 (B47, Table 1). Regarding zone S2, we calculated an

484

average Cf of about 12.01 (Table 1), which is the lowest values of the study area, suggesting these

485

watersheds are in a transient state in terms of landscape evolution. Hypsometric curves of

486

watersheds in zone S1 are S-shaped with HI values ranging from 0.40 (Basin B40) to 0.53 (Basin

487

43, Fig. 11, Table 1). Irregular hypsometric curves obtained for basins B39, B40, and B47 in zone

3

6

2

6

3

2

6

3

2

14

488

S1, as well as basin B52 in zone S2, show significant convexities in the normalized profiles (Fig.

489

11).

490

The ksn index results show exciting patterns along the SM. In general terms, highest values are

491

concentrated along the central SM, where the ksn index reaches values up to 800 (Fig. 12A). Low

492

relief areas as the Ocaña-Ábrego zone (Fig. 12B) and the Berlín Plateau are highlighted with low ksn

493

values (Fig. 12C). Along the northern SM, high ksn values are related to drainage basins draining

494

transversely the SM, both into the MMV and the Catatumbo basin, while longitudinal rivers are

495

characterized by low ksn values (Fig. 12B). At the Ocaña-Ábrego zone, low ksn values (<50) were

496

calculated, being these values common of tectonically inactive areas as the MMV, on the footwall of

497

the Bucaramanga Fault. An increase in ksn values is observed along the Filo Orocué (Fig. 1) and

498

continues increasing up to 400 at the Páramo de Guerrero (Fig. 12A). At the central SM, the Vetas

499

high is characterized by high anomalous values of the ksn index with high values on both drainage

500

basins draining into the MMV and the Táchira basin (Fig. 12C). Some anomalous values are

501

concentrated at the upper reaches of the Cáraba River (Fig. 12C), representing thus the actively

502

incising patterns into the low-relief Berlín Plateau. Regarding the main structures, high ksn values

503

are better related to the Bucaramanga Fault and NE-SW faults bounding the Berlin Plateau, at the

504

central SM. In terms of the zones proposed above, zones C1 and S1 have the highest mean ksn

505

(139.86 and 160.03, respectively), while the lowest values were obtained for zones N1 and N2

506

(108.29 and 94.58, respectively).

507

Regarding the Vf index (Table 1), results prove along-strike variations in incision patterns. In the

508

northern watersheds (zones N1, N2, C1, Table 1), the mean Vf value is of about 0.70, with the

509

lowest value obtained for basins B29 and B34 (0.11, Table 1). On the other hand, southern

510

watersheds (zones S1 and S2, Table 1) have a mean Vf value of about 0.38 with the lowest values

511

obtained for basins B50 in zone S1 and B57 in zone S2 (0.11 and 0.05, respectively, Table 1). We

512

classified the Vf index into several classes to discriminate areas where tectonic activity is ongoing

513

and areas where tectonics quiescent and erosion processes dominate. Class 1 for active incising

514

fronts with very high tectonic activity (Vf < 0.5), class 2 for high to moderate incising processes (0.5

515

< Vf < 1.0) and class 3 for low incision activity and dominant erosion processes (Vf > 1.0).

516

Accordingly, zones N1, N2, C1, and S1 can be grouped, preferably into classes 2, and 3, while

517

watersheds in zone S2 are better grouped into class 1, and therefore, it reflects along-strike

518

variations in incision patterns and local base level. This along-strike variation in tectonic activity can

519

be better observed by comparing the Hi values with the Vf index (Fig. 13). Both the linear trends for

520

the HI and Vf index show a positive correlation with an increase in relative recent tectonic activity

521

varying along-strike and increasing from NW to SE. Regarding the Bs index, zones S1 with an

522

average of 2.25 as well as N2 and S2 with an average of 2.13 (Table 1) show the highest values of

523

the study area. In zone S1, the Bs index varies from 1.380 to 2.975, with the highest values

524

concentrated between basin B38 to B42 (Table 1).

15

525

5. Discussion

526

5.1 The climate of tectonics? What is the primary driver of landscape evolution in the

527

Santander Massif?

528

We test the influence of climate on the geomorphological indices by performing a linear regression

529

analysis considering the MAP dataset as the independent variable and the mean basin relief, mean

530

basin gradient, HI, mean ksn, and Vf as the dependent variables. Along with the fitted regression

531

curve, we plotted the R2 coefficient and the p-value (Fig. 14), this later evaluating whether the

532

independent and dependent variables correlate in a broader population. We used a 5% significance

533

level to test the null hypothesis that the independent variable does not correlate with the dependent

534

variables. For all the tested metrics, we obtained low R values suggesting a weak correlation

535

between the MAP dataset and topography. The mean basin relief, mean basin gradient, and HI

536

metrics gave low p-values; thus, we reject the null hypothesis and expect a meaningful behavior of

537

the dependent variable related to changes in the MAP pattern (Fig. 14). We attribute this weak

538

correlation between topography and orographic enhanced precipitation to a merely spatial

539

correlation that, in turn, does not imply an erosional influence on exhumation and landscape

540

modeling (e.g., Whipple, 2009). It is worth noting how the MAP dataset is well-correlated with

541

basins showing local relief exceeding 900 m (Fig. 14a), which is a threshold value to create

542

enhanced precipitation on windward slopes in the Andes (Bookhagen and Strecker, 2008).

543

Therefore, we attribute the topographic and drainage network anomalies in this work to the

544

influence of regional tectonics and the Quaternary activity of faulting.

545

5.2 Insights on the Quaternary landscape evolution of the Santander Massif

546

Results shown in this work demonstrate along-strike topographic variations in several metrics (Fig.

547

7), suggesting a diachronic recent landscape evolution at the SM and asymmetric tectonic activity

548

related to the main structures of the study area. To better describe the asymmetric tectonic activity

549

within the study area, we discuss our results by considering four main areas: central and northern

550

SM, the Pamplona Indenter, and the western block of the Bucaramanga Fault that we report as the

551

Lebrija domain.

552

5.2.1

553

To the south of the study area, on the upthrown fault block of the Bucaramanga Fault (central SM),

554

several factors could be the primary driver of its high relief, high mean slope, channel steepness,

555

and HI values. From a regional viewpoint, Pleistocene to present escape of the northern Andes to

556

the NE (Audemard, 1998, 1993; Audemard and Audemard, 2002; Egbue and Kellogg, 2010; Mora-

557

Páez et al., 2018) had led to the “collision” between two regional tectono-stratigraphic blocks, i.e.,

558

the SM (Eastern Cordillera) and the Mérida Andes. This “collision” induced some along-strike

559

changes in the tectonic regime at the SM, with the central part under an E-W shortening in a pure

2

Central Santander Massif

16

560

compressive regime and the northern SM under a pure strike-slip regime where a transpressive

561

stress state has induced a regional domino-style faulting pattern (Velandia, 2017). The continuous

562

westward movement of the Mérida Andes (Bermúdez et al., 2015; Audemard and Audemard, 2002)

563

into the central SM has propagated deformation and crustal thickening and thus, exhumation has

564

unroofed basement rocks (Fig. 2). Recent low-temperature thermochronological data (Mora et al.,

565

2016; van der Lelij et al., 2016; Amaya-Ferreira et al., 2017) suggest that Miocene to Pliocene

566

exhumation events have been concentrated on inner structures along the SM, the Pamplona wedge

567

and the Labateca Block (Mérida domain). We hypothesize this exhumation event is the leading

568

driver of the high topographic values observed in this area, especially along the Vetas High (Figs. 7

569

and 12c).

570

This hypothesis is also confirmed by the presence of several anomalies in the ksn index. An

571

interesting pattern on the concavity steepness supports the interpretation mentioned about recent

572

surface uplift concentrated at central SM, i.e., high values of the ksn index regionally distributed at

573

almost the same elevation, emphasizing that drainages are responding to a constant and regional

574

change in base-level (Whipple et al., 2013). This base-level fall is evidenced by ongoing strong

575

incision patterns on the edges of the low-relief Berlín Plateau (Fig. 15A, B) and the Vetas High,

576

where the drainage network has sculpted deep V-shapes valleys (Fig. 15C) into strong lithologies

577

like orthogneisses and schists (Fig. 2). The regional pattern of the ksn index at the central SM is

578

distributed along areas with little lithological variation (Fig. 2), signifying that the main driver in the

579

anomalous values of the index is a recent surface uplift event that we attribute to the westward

580

motion of the Pamplona Indenter towards the central SM.

581

The Bucaramanga Fault, a striking regional structure delimiting the SM from the MMV, also

582

presents geomorphological evidence for recent tectonic activity at the central SM. This hypothesis is

583

strongly supported by the presence of poorly-graded profiles in zones S1 and S2 (Fig. 10), as well

584

as S-shaped to slightly convex hypsometric curves (Fig. 11). Recent surface uplift associated with a

585

reverse displacement on the upthrown block of the Bucaramanga Fault induces local topographic

586

rejuvenation leading to the occurrence of anomalous hypsometric curves with convex lower

587

reaches. Besides this, the drainage network responses to surface uplift with increased erosion

588

through changes in local base-level, creating thus V-shaped gorges. Low Vf values averaging 0.38

589

in this area, as well as geomorphic features like strath terraces (Fig. 15D) in the lower reaches of

590

the Cáchira River (Fig. 1) suggest that streams on the eastern block of the Bucaramanga Fault are

591

strongly incising into the crystalline basement of the SM. This undoubted evidence underscores the

592

recent surface uplift interpreted along this remarkable structure. Considering the low Vf values in

593

zones S1 and S2, the straightness of the mountain front (Fig. 3) and the preservation of

594

morphostructural features evidencing the Quaternary tectonic activity of the fault, we should expect

595

an empirical uplift rate above 0.08 mm/yr (Silva et al., 2003).

17

596

Although the Bucaramanga Fault has been mostly recognized as a pure strike-slip fault with some

597

outstanding morphostructural features such as pressure ridges, sag ponds, shutter ridges, etc.

598

(e.g., Osorio et al., 2008; Galvis et al., 2014; Velandia and Bermúdez, 2018), recent

599

thermochronological works have accentuated the weight of the dip-slip component (oblique-

600

contraction) of the structure during topographic building of the SM (e.g., Siravo et al., 2019), an

601

approach that we comprehend is also supported by our geomorphic analysis.

602

In tectonically active areas, higher uplift rates are often compensated by an increase in erosion

603

rates that facilitates the equilibrium between tectonics and topography. Given the fluvial network is

604

continuously connected with surface uplift, bedrock rivers revoke the tectonic forcing through

605

channel steepening, prompting higher erosion rates (Ouimet et al., 2009; Wobus et al., 2006). Our

606

results in the ksn index, a proxy for erosion (Kirby et al., 2012), support the above interpretations of

607

ongoing surface uplift on the upthrown faulted block of the Bucaramanga Fault. The aligned

608

anomalous ksn values following the fault trace of the Bucaramanga Fault (Fig. 12a) are interpreted

609

as a temporal change in rock uplift (Wobus et al., 2006; Kirby and Whipple, 2012; Whipple et al.,

610

2013). The high ksn values provide compelling evidence of the continuing increase in channel

611

gradient that, in turn, promotes headward erosion and active incision in this area. Although the

612

Bucaramanga Fault has been considered in previous works as a left-lateral strike-slip structure,

613

evidencing lateral displacements of Quaternary non-consolidated deposits (e.g., Diederix et al.,

614

2009; Jiménez et al., 2015), we attribute the surface uplift pattern on the western edge of the SM to

615

a reverse component as a response to a transpressional stress state as emphasized (Siravo et al.,

616

2019). These authors reported more significant exhumation rates on the eastern block of the

617

Bucaramanga Fault than in the western block (Lebrija domain), explaining thus the noticeable

618

differences in topography resulting from the Andean activity of the fault. Hence, the

619

thermochronological data within the SM (van der Lelij et al., 2016; Amaya et al., 2017; Siravo et al.,

620

2019), along with the geomorphological observations made, strongly supports our hypothesis that

621

the Bucaramanga Fault has been sculpting the SM landscape both in the long (10 -10 yr) and the

622

short-term (10 -10 ).

623

5.2.2

624

Unlike the central SM, the northern SM is characterized by low relief, low mean slope, low HI and

625

medium to low ksn values, except for some areas as the faulted block between the Bucaramanga

626

and Guamalito faults (Figs. 7 and 12b), near the Filo Orocué (Fig. 1). From the MMV to the Filo El

627

Romero (Fig. 1), local relief has several peaks interpreted here as an evidence of sharp incision

628

after recent uplift along the Bucaramanga and Guamalito Fault, as well as fault activity associated

629

with the transverse structures (NE-SW striking faults, Fig. 5c). These transverse structures play a

630

crucial role as they behave as transverse zones, controlling the structural style and inducing block

631

segmentation. Transverse zones are lateral connectors transverse or oblique to the tectonic

5

3

6

4

Northern Santander Massif

18

632

transport direction that influence along-strike variations in structural style (Thomas, 1990; Garcia

633

and Jimenez, 2016). As it was mentioned above, in the northern zone of the SM, the tectonic

634

regime has a primary strike-slip component (Velandia, 2017). However, this structure presents an

635

increase in local relief (up to 1000 m, SP3, Fig. 5c) on the upthrown fault block towards the south,

636

which summed to the Q3 profile close to the maximum topography (Fig. 5c), depicts a young relief

637

that is being incised by a drainage network (e.g., Pérez-Peña et al., 2017), this later might

638

suggesting a significant dip-slip component deforming the inner SM near Filo Orocué.

639

On the other hand, the Ocaña-Ábrego zone is remarkable for being a low-relief intramontane basin

640

(Fig. 15E), which we assume as a relict landscape with an older drainage network preserved. We

641

based this interpretation on the presence of thick non-consolidated deposits that have not been

642

recycled by the orogen activity (Fig. 2). Preservation of Miocene-Pliocene (?) alluvial deposits of the

643

Algodonal Formation (Fig. 15F) suggests low vertical deformation along the Guamalito Fault and

644

dominant strike-slip kinematics. Reversal of the Algodonal River with a dramatic change in flow

645

direction from NE-SW to NW-SE and finally SW-NE to continue into the Catatumbo Basin

646

demonstrates that this area records a relict drainage network (white arrow, Fig. 12B). We

647

hypothesized that this relict drainage system drained the SM in a NE-SW direction into the MMV,

648

but recent surface uplift between the Bucaramanga and Guamalito faults isolated and diverted the

649

stream to an NW-SE direction, parallel to the structural grain of the SM. The drainage network was

650

later captured by headward erosion of rivers draining into the Catatumbo Basin. When a capture

651

event has been positive, the rerouting of the drainage network leaves behind a capture knickpoint

652

reflecting the height difference between the aggressor and the victim streams (Bishop, 1995). We

653

tentatively identified what seems a capture knickpoint where stream flow changes from NNW to

654

NNE towards the Catatumbo Basin (Fig. 12B). Besides, high ksn values on these streams draining

655

into the Catatumbo basin (Fig. 12B) are interpreted as a transient landscape responding to active

656

faulting along the faulted block between the Haca Fault and the MMFS. To the southeast of this

657

area, high ksn values were associated with recent tectonic activity along the Zulia Fault System

658

(Oviedo-Reyes, 2015); therefore, it could be interpreted that the eastern foothills of the SM are

659

under active deformation. If this scenario is feasible, the Algodonal Formation records the eroded

660

material coming from the unroofed basement rocks in the eastern foothills of the SM during the

661

most significant exhumation event associated with the Andean Orogeny.

662

Regarding the western foothills, the presence of knickpoints (Fig. 12B) within the tectonic domain at

663

almost constant contour lines (between 500 and 700 m in elevation) reveals a transient signal

664

migrating upstream in the channel network. In transient bedrock rivers, as we already stated within

665

the study area, those knickpoints mark the boundary between the adjusting and relict regions that

666

have been affected by a base-level fall (usually set by rock uplift rate) or a change in bedrock

667

erodibility (Whipple et al., 2013). Given the streams west of Aguachica drains variable lithologies

668

(mostly Jurassic sedimentary rocks, Fig. 2), we attribute these anomalies in the ksn index to a

19

669

persistent change in surface uplift that generated upstream migrating knickpoints (Whipple et al.,

670

2013). The knickpoints identified on the streams draining the western piedmont in the Northern SM

671

suggest that knickpoint formation is the result of a transient fluvial response to fault-related uplift

672

during the late Neogene activity of the Bucaramanga Fault. It has been observed that after fault

673

initiation (or in this case, reactivation), the subsequent uplift acceleration creates slope-break

674

knickpoints that propagates through the river network, causing the increase in the channel

675

steepness (Wobus et al., 2006; Whittaker and Boulton, 2012; Whipple et al., 2013; Liu et al., 2019).

676

If our interpretation is feasible, we understand that in the short-term, the reverse component of the

677

Bucaramanga Fault becomes more significant at the Aguachica area, where it facilitates the

678

topographic building of the orogen.

679

Both the qualitative and quantitative evidence reported in this work strongly suggests strain

680

partitioning (Fossen et al., 1994; Tikoff and Teyssier, 1994) in the domain bounded by the

681

Bucaramanga and Haca faults. Within this domain, the simple lateral shear is taken up along the

682

Haca and Guamalito faults while the remaining pure-shear component is partially consumed along

683

the Bucaramanga Fault and the segment of the Guamalito Fault near Ábrego. Although the

684

accretion of the Panamá Arc (Fig. 1) onto the western margin of the Northern Andes during middle

685

Miocene (Duque-Caro, 1990) has been stated as the responsible for the exhumation of the SM (van

686

der Lelij et al., 2016; Amaya et al., 2017), we interpret the recent landscape evolution of the range

687

as a consequence of the westward motion of the Pamplona Indenter towards the SM, which

688

transmitted a transpressional stress state and a more rapid uplift rates in those areas where the

689

inherited anisotropies take contractional deformation.

690

5.2.3

691

As we mentioned above, the higher uplift rates evidenced by the highest ksn values were recorded

692

for the central SM, in the deformation front of the Pamplona Indenter. However, the drainage

693

network within the Pamplona domain is showing a transient signal which we attempt to explain next.

694

Late Miocene to recent exhumation has been reported on the hanging wall of the Chitagá Fault

695

(Mora et al., 2015) within the Labateca Block (Fig. 12C). Although these authors reiterate previous

696

interpretations about climate-driven denudation is the primary agent shaping the landscape

697

evolution in the Eastern Cordillera of Colombia (e.g., Mora et al., 2008; Ramírez-Arias et al., 2012),

698

the short-term precipitation data in this area reveal MAP values below 1000 m that hardly promotes

699

fluvial unloading and climate-driven exhumation. Therefore, the noteworthy incision of the Chitagá

700

River into the Labateca Block is in the function of a regional base-level drop following the Neogene

701

exhumation history in this domain. Pliocene to Quaternary tectonic activity on the hanging wall of

702

the Chitagá Fault is revealed not only by younger AFT cooling ages (Mora et al., 2015) but also by

703

high ksn values above 200 (Fig. 12C). The faster uplift associated with the Labateca block suggests

704

that the two colliding blocks (Mérida Andes versus Santander Massif) have been deforming

Pamplona Indenter

20

705

reciprocally since the onset of deformation. Although both blocks have been deformed, the more

706

persistent and extended unroofing of basement rocks in the deformation front of the Pamplona

707

Indenter, at the central SM, and the more recent exhumation history within the Labateca Block are

708

here interpreted to evoke diachronous deformational history. This behavior is highly indicative of

709

lithospheric strength contrasts (Keep, 2000; Willingshofer et al., 2005), with the SM being weaker

710

than the Mérida domain. Therefore, when the oblique collision began, the SM deformed first at the

711

edges of the Pamplona Indenter through strike-slip deformation (e.g., the Boconó Fault, Fig. 2) and

712

further crustal thickening at the deformation front, creating the irregular topography of the central

713

SM (Fig. 7). Based on the published AFT data, the onset of this deformation event is Miocene (Fig.

714

12) (Mora et al., 2015; van der Lelij et al., 2016; Amaya et al., 2017). Continuing extrusion of the

715

SM and the accelerated escape of the Northern Andes during Pleistocene times (Egbue and

716

Kellogg, 2012) may create a response on the stronger crustal portion of the Pamplona Indenter,

717

leading to the unroofing of Paleozoic sedimentary rocks and the abrupt drainage network response

718

to tear down the topographic anomaly through river incision and denudation.

719

5.2.4

720

Topographic analysis on the western block of the Bucaramanga Fault suggests relatively moderate

721

to low tectonic activity. Swath SP6 shows that in this area, quartile Q3 separates from maximum

722

topography, suggesting a mature landscape; low values of THi* supports the assumption that there

723

has not been recent uplift within the block bounded by the Lebrija and Bucaramanga faults (Fig.

724

6b). Thick Quaternary fluvio-alluvial deposits of the Bucaramanga Terrace (up to 300 m in

725

thickness) located to the west of the Bucaramanga Fault evidence an isolated block where low dip-

726

slip deformation within this block during Pleistocene times favored deposition of eroded materials

727

from the central and southern SM (Julivert, 1958; De Porta, 1959; Jiménez et al., 2015). Low THi*

728

values, as well as the Q3 profile close to the mean topography in swath SP6, supports this

729

interpretation (Fig. 6c). The Bucaramanga area is recognizable by presenting low values in both the

730

relief and mean slope maps, funding the above interpretations that erosion and later aggradational

731

processes have dominated over tectonism since Pleistocene times. Localized Quaternary

732

deformation in this area is constrained to faulted Pleistocene deposits of the Bucaramanga Terrace

733

because of the Suárez Fault (Julivert, 1963).

734

5.3 Drainage evolution in the SM and surrounding areas

735

Analysis of normalized longitudinal profiles demonstrates that rivers draining the eastern flank of the

736

SM has an asymmetric behavior in their erosional state. Most rivers along the southern zones, at

737

the central SM, are larger, have low MaxC and Cf values, besides several convexities in the upper

738

reaches, which suggest that these basins are in a transient state (Ruszkiczay-Rüdiger et al., 2009;

739

Matoš et al., 2016). Conversely, rivers in the northern zones are shorter, and they are closer to an

740

equilibrium state than southern rivers (Figs. 9, 10 and 11). Moreover, the preservation of

Western block: Lebrija domain

21

741

longitudinal rivers along the northern SM and the reversal of the Algodonal river (Fig. 12A) suggest

742

that this region has been subjected to minor vertical deformation in recent times. Recent studies on

743

drainage systems along orogens have proposed that rivers evolve from a longitudinal to a

744

transverse pattern as the regional slope increases with mountain building (Babault et al., 2013).

745

This model has been invoked to explain the evolution of the drainage system at the central segment

746

of the Eastern Cordillera (Struth et al., 2015, 2017). According to our drainage analysis, the SM

747

shows two different stages in the evolutionary stage of the drainage system. The southern part

748

(central SM) corresponds to the most evolved landscape with slope-dominated transverse rivers

749

(Fig. 1) incising into the highest topographic areas like the Berlín Plateau (Fig. 15B) as a response

750

of deformation, uplift and further crustal thickening in Miocene-Pliocene times (Van der Lelij et al.,

751

2016; Amaya et al., 2017).

752

Conversely, the northern drainage basins (zones N1, N2 and C1, Fig. 3) preserve structurally

753

controlled rivers (Fig. 1) in an evolutionary state equal to the central Eastern Cordillera drainage

754

system. Accordingly, the Ocaña-Ábrego zone is an outstanding low-relief relict landscape (Fig. 15E)

755

where further studies can offer new insights on the exhumation and later uplift patterns along the

756

inner SM. This area represents a middle ground in the evolutionary state between longitudinal and

757

transversely slope-controlled rivers.

758

5.4 Limitations of this work and further research needs

759

This work is a DEM-based comprehensive geomorphological analysis with well-known geomorphic

760

indices that have proved to work correctly in tectonically active areas, and partially supported by

761

regional field survey carried out in the past five years. However, we underscore the need to

762

thoroughly test the hypotheses proposed regarding the Neogene influence of the Pamplona

763

Indenter in building the remarkable topography and relief at central SM. New thermochronological

764

data in this area will reduce the uncertainty in the exhumation patterns and the thermal influence on

765

the hanging wall of the Bucaramanga Fault. Although our work is in good agreement with published

766

low-temperature thermochronology and explains fairly good the kinematics of the main structures,

767

further works providing quantitative erosion rates and detailed structural information will shed light

768

on the assumptions made. The fundamental conclusion of our work that tectonics is the primary

769

factor shaping the long to short-term landscape evolution of the SM is in our thoughts, well-

770

supported by the regional erosion patterns described from the geomorphic metrics evaluated.

771

6. Conclusions

772

The quantitative geomorphological analysis conducted in this work has demonstrated that along-

773

strike topographic changes in the SM are controlled by differentiated tectonic activity in the long to

774

short-term. This tectonic activity can be separated into two different sceneries: (i) the widespread

775

deformation of the central SM induced by the westward motion of the Pamplona Indenter (Mérida

22

776

domain), which in turn is proposed as the main driver of the high values of local relief, mean slope,

777

filtered topography, HI and ksn in this zone; (ii) Late Neogene activity along the Bucaramanga Fault

778

(evidenced by aligned high ksn values) and the NE-SW faults. This second scenario is reinforced by

779

the identification of an erosional wave on streams draining the western piedmont of the SM that

780

reflects a transient fluvial response to fault-related uplift during the late Neogene activity of the

781

Bucaramanga Fault. Our quantitative data is in good agreement with published AFT data,

782

suggesting thus a coupling between long-term exhumation and short-term landscape evolution in

783

the SM. Considering the historical seismicity along the central SM and that NE-SW faults show

784

recent tectonic activity, further studies will be oriented to understand if these structures are related

785

to historical earthquakes.

786

On the other hand, minor surface uplift across the inner part of the northern SM, at the Ocaña-

787

Ábrego zone, has preserved a relict landscape where the north-trending internal drainage network

788

was recently captured by streams draining into the Catatumbo Basin. Fluvial reorganization in the

789

northern SM from longitudinal to transverse slope-dominated streams was induced by surface uplift

790

along the Haca Fault and the MMFS because of the recent tectonic activity in the eastern foothills of

791

the range. This drainage reorganization pattern shares similarities with the drainage evolution

792

model proposed for the Eastern Cordillera of Colombia. Quaternary tectonic activity in the northern

793

SM is better constrained to the faulted block between the Bucaramanga and Guamalito faults,

794

where late Neogene fault-related uplift has influenced the long to short-term landscape evolution in

795

this zone. Therefore, the northern segment of the Bucaramanga Fault (between La Esperanza and

796

Aguachica) had recent dip-slip deformation, and it is the primary driver of short-term landscape

797

evolution in the transition zone between the SM and the MMV.

798

Acknowledgments

799

The authors would like to thank the anonymous reviewers for their comments and criticism. We also

800

thank editor-in-chief Andrés Folguera for the handling of the manuscript. H. García is grateful to

801

Nicolás Villamizar for his support when interpreting low-temperature thermochronology data.

802

7. References

803

Acosta, J., Velandia, F., Osorio, J., Lonergan, L., Mora, H., 2007. Strike-slip deformation within the

804

Colombian

805

https://doi.org/10.1144/GSL.SP.2007.272.01.16

806

Amaya, S., Zuluaga, C.A., Bernet, M., 2017. New fission-track age constraints on the exhumation of

807

the central Santander Massif: Implications for the tectonic evolution of the Northern Andes,

808

Colombia. Lithos 282–283, 388–402. https://doi.org/10.1016/j.lithos.2017.03.019

Andes.

Geol.

Soc.

London,

Spec.

Publ.

272,

303–319.

23

809

Andreani, L., Stanek, K.P., Gloaguen, R., Krentz, O., Domínguez-González, L., 2014. DEM-based

810

analysis of interactions between tectonics and landscapes in the ore mountains and eger rift (East

811

Germany

812

https://doi.org/10.3390/rs6097971

813

Andriessen, P.A.M., Helmens, K.F., Hooghiemstra, H., Riezebos, P.A., Van der Hammen, T., 1993.

814

Absolute chronology of the Pliocene-Quaternary sediment sequence of the Bogota area, Colombia.

815

Quat. Sci. Rev. 12, 483–501. https://doi.org/10.1016/0277-3791(93)90066-U

816

Antón, L., De Vicente, G., Muñoz-Martín, A., Stokes, M., 2014. Using river long profiles and

817

geomorphic indices to evaluate the geomorphological signature of continental scale drainage

818

capture,

819

https://doi.org/10.1016/j.geomorph.2013.09.028

820

Arias, A., Vargas, R., 1978. Geología de las Planchas 86 Abrego y 97 Cáchira. Bol. Geológico Vol.

821

23, 3–38.

822

Audemard, F.A., 1998. Evolution Géodynamique de la Façade Nord Sud-américaine : Nouveaux

823

apports de l’Histoire Géologique du Bassin de Falcón, Vénézuéla, in: Transactions of the 3rd

824

Geological Conference of the Geological Society of Trinidad and Tobago and the XIV Caribbean

825

Geological Conference, Trinidad-1995. pp. 327–340.

826

Audemard, F.A., 1993. Néotectonique, Sismotectonique et Aláa Sismique du Nord-ouest du

827

Vénézuéla (Systeme de failles d’Oca-Ancón). Université Montpellier II, France.

828

Audemard, Felipe, Audemard, Franck, 2002. Structure of the Mérida Andes, Venezuela: Relations

829

with the south America-Caribbean geodynamic interaction. Tectonophysics 345, 299–327.

830

Azañón, J.M., Galve, J.P., Pérez-Peña, J. V., Giaconia, F., Carvajal, R., Booth-Rea, G., Jabaloy, A.,

831

Vázquez, M., Azor, A., Roldán, F.J., 2015. Relief and drainage evolution during the exhumation of

832

the Sierra Nevada (SE Spain): Is denudation keeping pace with uplift? Tectonophysics 663, 19–32.

833

https://doi.org/10.1016/j.tecto.2015.06.015

834

Babault, J., Teixell, A., Struth, L., Van Den Driessche, J., Arboleya, M.L., Tesón, E., 2013.

835

Shortening, structural relief and drainage evolution in inverted rifts: insights from the Atlas

836

Mountains, the Eastern Cordillera of Colombia and the Pyrenees. Geol. Soc. London, Spec. Publ.

837

377, 141–158. https://doi.org/10.1144/SP377.14

838

Bellin, N., Vanacker, V., Kubik, P.W., 2014. Denudation rates and tectonic geomorphology of the

839

Spanish

840

https://doi.org/10.1016/j.epsl.2013.12.045

and

Duero

Betic

NW

Czech

basin

Cordillera.

Republic).

(NW

Earth

Remote

Iberia).

Planet.

Sens.

Geomorphology

Sci.

Lett.

6,

7971–8001.

206,

390,

250–261.

19–30.

24

841

Bermúdez, M.A., Hoorn, C., Bernet, M., Carrillo, E., van der Beek, P.A., Garver, J.I., Mora, J.L.,

842

Mehrkian, K., 2015. The detrital record of late-Miocene to Pliocene surface uplift and exhumation of

843

the Venezuelan Andes in the Maracaibo and Barinas foreland basins. Basin Res. 29, 1–26.

844

https://doi.org/10.1111/bre.12154

845

Bishop, P., 1995. Drainage rearrangement by river capture, beheading and diversion. Prog. Phys.

846

Geogr. 19, 449–473. https://doi.org/10.1177/030913339501900402

847

Boinet, T., Bourgois, J., Mendoza, H., 1982. Tectónica de sobrecorrimiento y sus implicaciones

848

estructurales en el área de Pamplona-Labateca. Cordillera Oriental de Colombia. Bol. Geol. 15, 67–

849

79.

850

Boinet, T., Bourgois, J., Mendoza, H., Vargas, R., 1985. Le poinçon de Pamplona (Colombie) ; un

851

jalon de la frontière méridionale de la plaque caribe. Bull. la Soc. Geol. Fr. Huit. Ser. 1, 403–413.

852

Bookhagen, B., Burbank, D.W., 2006. Topography, relief, and TRMM-derived rainfall variations

853

along the Himalaya. Geophys. Res. Lett. 33, 1–5. https://doi.org/10.1029/2006GL026037

854

Bookhagen, B., Strecker, M.R., 2008. Orographic barriers, high-resolution TRMM rainfall, and relief

855

variations

856

https://doi.org/10.1029/2007GL032011

857

Brocklehurst, S.H., Whipple, K.X., 2002. Glacial erosion and relief production in the Eastern Sierra

858

Nevada, California. Geomorphology 42, 1–24. https://doi.org/10.1016/S0169-555X(01)00069-1

859

Bull, W.B., McFadden, L.D., 1977. Tectonic geomorphology north and south of the Garlock fault,

860

California, in: Doehering, D.O. (Ed.), Geomorphology in Arid Regions Proceedings at the Eighth

861

Annual Geomorphology Symposium. State University of New York, Binghamton, 23-24 September

862

1977, pp. 115–138.

863

Burbank, D.W., Anderson, R.S., 2012. Tectonic Geomorphology, 2nd ed, Wiley-Blackwell. Blackwell

864

Publishing. https://doi.org/10.1130/L15.1.

865

Calzolari, G., Della Seta, M., Rossetti, F., Nozaem, R., Vignaroli, G., Cosentino, D., Faccenna, C.,

866

2016. Geomorphic signal of active faulting at the northern edge of Lut Block: Insights on the

867

kinematic scenario of Central Iran. Tectonics 35, 76–102. https://doi.org/10.1002/2015TC003869

868

Cannon, P., 1976. Generation of explicit parameters for a quantitative geomorphic study of the Mill

869

creek drainage basin. Oklahoma Geol. Notes 36, 3–17.

870

Cederbom, C.E., Sinclair, H.D., Schlunegger, F., Rahn, M.K., 2004. Climate-induced rebound and

871

exhumation of the European Alps. Geology 32, 709–712. https://doi.org/10.1130/G20491.1

along

the

eastern

Andes.

Geophys.

Res.

Lett.

35,

1–6.

25

872

Cediel, F., Shaw, R., Caceres, C., 2003. Tectonic Assembly of the Northern Andean block, in The

873

Circum-Gulf of Mexico and the Caribbean: Hydrocarbon Habitats, Basin Formation and Plate

874

Tectonics. Am. Assoc. Pet. Geol. Bull. 79, 815–848.

875

Cheng, Y., He, C., Rao, G., Yan, B., Lin, A., Hu, J., Yu, Y., Yao, Q., 2018. Geomorphological and

876

structural characterization of the southern Weihe Graben, central China: Implications for fault

877

segmentation. Tectonophysics 722, 11–24. https://doi.org/10.1016/j.tecto.2017.10.024

878

Cifuentes, H., Sarabia, A.M., 2009. Estudio Macrosísmico del sismo del 16 de Junio de 1961,

879

Ocaña (Norte de Santander). Internal report.

880

Cifuentes, H., Sarabia, A.M., 2007a. Estudio macrosísmico del sismo del 16 de Enero de 1644,

881

Pamplona (Norte de Santander). Internal report.

882

Cifuentes, H., Sarabia, A.M., 2007b. Estudio macrosísmico del sismo del 8 de Julio de 1950,

883

Arboledas (Norte de Santander). Internal report.

884

Cifuentes, H., Sarabia, A.M., 2006. Estudio macrosísmico del sismo del 18 de Mayo De 1875,

885

Cúcuta (Norte De Santander). Internal report.

886

Cooper, M. al, Addison, F.T., Alvarez, R., Coral, M., Graham, R.H., Hayward, A.B., Howe, S.,

887

Martinez, J., Naar, J., Peñas, R., Pulham, A.J., Taborda, A., 1995. Basin development and tectonic

888

history of the Llanos basin, and Middle Magdalena Valley, Colombia. Pet. basins South Am. AAPG.

889

Mem. no. 62 10, 659–666. https://doi.org/10.1306/7834D9F4-1721-11D7-8645000102C1865D

890

Corredor, F., 2003. Eastward extent of the late Eocene-Early Oligocene onset of deformation

891

across the northern Andes: Constraints from the northern portion of the Eastern Cordillera fold belt,

892

Colombia. J. South Am. Earth Sci. 16, 445–457. https://doi.org/10.1016/j.jsames.2003.06.002

893

De Porta, J., 1959. La Terraza de Bucaramanga. Boletín Geol. 3, 5–13.

894

Demoulin, A., 1998. Testing the tectonic significance of some parameters of longitudinal river

895

profiles: the case of the Ardenne (Belgium, NW Europe). Geomorphology 24, 189–208.

896

https://doi.org/10.1016/S0169-555X(98)00016-6

897

Diederix, H., Hernández, C., Torres, E., Osorio, J.A., Botero, P., 2009. Resultados preliminares del

898

primer estudio paleosismológico a lo largo de la Falla de Bucaramanga, colombia. Ing. Investig. y

899

Desarro. 9, 18–23.

900

Duque-Caro, H., 1990. The choco block in the northwestern corner of South America: Structural,

901

tectonostratigraphic, and paleogeographic implications. J. South Am. Earth Sci. 3, 71–84.

902

https://doi.org/10.1016/0895-9811(90)90019-W

26

903

Egbue, O., Kellogg, J., 2010. Pleistocene to Present North Andean “escape.” Tectonophysics 489,

904

248–257. https://doi.org/10.1016/j.tecto.2010.04.021

905

El Hamdouni, R., Irigaray, C., Fernández, T., Chacón, J., Keller, E.A., 2008. Assessment of relative

906

active tectonics, southwest border of the Sierra Nevada (southern Spain). Geomorphology 96, 150–

907

173. https://doi.org/10.1016/j.geomorph.2007.08.004

908

Faccenna, C., Molin, P., Orecchio, B., Olivetti, V., Bellier, O., Funiciello, F., Minelli, L., Piromallo, C.,

909

Billi, A., 2011. Topography of the Calabria subduction zone (southern Italy): Clues for the origin of

910

Mt. Etna. Tectonics 30, 1–20. https://doi.org/10.1029/2010TC002694

911

Flint, J.J., 1974. Stream Gradient as a Function of Order, Magnitude, and Discharge. Water Resour.

912

Res. 10, 969–973.

913

Forte, A.M., Whipple, K.X., 2018. Short communication: The Topographic Analysis Kit (TAK) for

914

TopoToolbox. Earth Surf. Dyn. Discuss. 1–9. https://doi.org/10.5194/esurf-2018-57

915

Fossen, H., Tikoff, B., Teyssier, C., 1994. Strain modeling of transpressional and transtensional

916

deformation. Nor. Geol. Tidsskr. 74, 134–145.

917

Gaidzik, K., Ramírez-Herrera, M.T., 2017. Geomorphic indices and relative tectonic uplift in the

918

Guerrero

919

https://doi.org/10.1016/j.gsf.2016.07.006

920

Galvis, M., Velandia, F., Villamizar, N., 2014. Cartografía morfoestructural de la Falla de

921

Bucaramanga: geometría lenticular a lo largo del valle del río Chicamocha en Santander -

922

Colombia, in: XVII Congreso Peruano de Geología. Lima, Peru.

923

Garcia, H., Jimenez, G., 2016. Transverse zones controlling the structural evolution of the Zipaquira

924

Anticline (Eastern Cordillera, Colombia): Regional implications. J. South Am. Earth Sci. 69, 243–

925

258. https://doi.org/10.1016/j.jsames.2016.04.002

926

Ghisetti, F., Sibson, R.H., Hamling, I., 2016. Deformed Neogene basins, active faulting and

927

topography in Westland: Distributed crustal mobility west of the Alpine Fault transpressive plate

928

boundary

929

https://doi.org/10.1016/j.tecto.2016.03.024

930

Giaconia, F., Booth-Rea, G., Martínez-Martínez, J.M., Azañón, J.M., Pérez-Peña, J.V., Pérez-

931

Romero, J., Villegas, I., 2012a. Geomorphic evidence of active tectonics in the Sierra Alhamilla

932

(eastern

933

https://doi.org/10.1016/j.geomorph.2011.12.043

sector

(South

Betics,

of

the

Island,

SE

Mexican

New

forearc.

Zealand).

Spain).

Geosci.

Front.

Tectonophysics

Geomorphology

8,

693,

145–146,

885–902.

340–362.

90–106.

27

934

Giaconia, F., Booth-Rea, G., Martínez-Martínez, J.M., Azañón, J.M., Pérez-Peña, J. V., 2012b.

935

Geomorphic analysis of the Sierra Cabrera, an active pop-up in the constrictional domain of

936

conjugate strike-slip faults: The Palomares and Polopos fault zones (eastern Betics, SE Spain).

937

Tectonophysics 580, 27–42. https://doi.org/10.1016/j.tecto.2012.08.028

938

Godard, V., Bourlès, D.L., Spinabella, F., Burbank, D.W., Bookhagen, B., Fisher, G.B., Moulin, A.,

939

Léanni, L., 2014. Dominance of tectonics over climate in Himalayan denudation. Geology 42, 243–

940

246. https://doi.org/10.1130/G35342.1

941

Helmens, K.F., 2004. The Quaternary glacial record of the Colombian Andes, in: Ehlers, J.,

942

Gibbard, P.L. (Eds.), Quaternary Glaciations - Extent and Chronology, Part III. pp. 115–134.

943

https://doi.org/10.1016/S1571-0866(04)80117-9

944

Jiménez, G., Speranza, F., Faccena, C., Bayona, G., Mora, A., 2015. Magnetic stratigraphy of the

945

Bucaramanga alluvial fan: Evidence for a ≤3mm/yr slip rate for the Bucaramanga-Santa Marta

946

Fault, Colombia. J. South Am. Earth Sci. 57, 12–22. https://doi.org/10.1016/j.jsames.2014.11.001

947

Jiménez, G., Speranza, F., Faccenna, C., Bayona, G., Mora, A., 2014. Paleomagnetism and

948

magnetic fabric of the Eastern Cordillera of Colombia: Evidence for oblique convergence and

949

nonrotational reactivation of a Mesozoic intracontinental rift. Tectonics 33, 2233–2260.

950

https://doi.org/10.1002/2014TC003532

951

Julivert, M., 1963. Nuevas observaciones sobre la estratigrafía y tectónica del Cuaternario de los

952

alrededores de Bucaramanga. Bol. Geol. 41–59.

953

Julivert, M., 1958. La Morfoestructura de la zona de las mesas al SW de Bucaramanga (Colombia

954

S.A.). Bol. Geol. 1, 7–43.

955

Kammer, A., 1999. Observaciones acerca de un Origen Transpresivo de la Cordillera Oriental.

956

Geol. Colomb. 24, 29–53.

957

Keep, M., 2000. Models of lithospheric-scale deformation during plate collision: Effects of indentor

958

shape and lithospheric thickness. Tectonophysics 326, 203–216. https://doi.org/10.1016/S0040-

959

1951(00)00123-2

960

Keller, E., Pinter, N., 2002. Active Tectonics: Earthquakes, uplift and landscape, second. ed,

961

Pearson Education. Pearson Education.

962

Kirby, E., Whipple, K.X., 2012. Expression of active tectonics in erosional landscapes. J. Struct.

963

Geol. 44, 54–75. https://doi.org/10.1016/j.jsg.2012.07.009

28

964

Kothyari, G.C., Kandregula, R.S., Luirei, K., 2017. Morphotectonic records of neotectonic activity in

965

the vicinity of North Almora Thrust Zone, Central Kumaun Himalaya. Geomorphology 285, 272–286.

966

https://doi.org/10.1016/j.geomorph.2017.02.021

967

Kothyari, G.C., Rastogi, B.K., Morthekai, P., Dumka, R.K., Kandregula, R.S., 2016. Active

968

segmentation assessment of the tectonically active South Wagad Fault in Kachchh, Western

969

Peninsular India. Geomorphology 253, 491–507. https://doi.org/10.1016/j.geomorph.2015.10.029

970

Koukouvelas, I.K., Zygouri, V., Nikolakopoulos, K., Verroios, S., 2018. Treatise on the tectonic

971

geomorphology of active faults: The significance of using a universal digital elevation model. J.

972

Struct. Geol. https://doi.org/10.1016/j.jsg.2018.06.007

973

Liu, Z., Han, L., Boulton, S.J., Wu, T., Guo, J., 2019. Quantifying the transient landscape response

974

to active faulting using fluvial geomorphic analysis in the Qianhe Graben on the southwest margin

975

of Ordos, China. Geomorphology 351, 106974. https://doi.org/10.1016/j.geomorph.2019.106974

976

Matoš, B., Pérez-Peña, J.V., Tomljenović, B., 2016. Landscape response to recent tectonic

977

deformation in the SW Pannonian Basin: Evidence from DEM-based morphometric analysis of the

978

Bilogora

979

https://doi.org/10.1016/j.geomorph.2016.03.020

980

Menéndez, I., Silva, P.G., Martín-Betancor, M., Pérez-Torrado, F.J., Guillou, H., Scaillet, S., 2008.

981

Fluvial dissection, isostatic uplift, and geomorphological evolution of volcanic islands (Gran Canaria,

982

Canary

983

https://doi.org/10.1016/j.geomorph.2007.06.022

984

Molin, P., Fubelli, G., Nocentini, M., Sperini, S., Ignat, P., Grecu, F., Dramis, F., 2012. Interaction of

985

mantle dynamics, crustal tectonics, and surface processes in the topography of the Romanian

986

Carpathians:

987

https://doi.org/10.1016/j.gloplacha.2011.05.005

988

Molin, P., Pazzaglia, F., Dramis, F., 2004. Geomorphic expression of active tectonics in a rapidly-

989

deforming

990

https://doi.org/10.1126/science.3.53.32

991

Mora-Páez, H., Kellogg, J.N., Freymueller, J.T., Mencin, D., Fernandes, R.M.S., Diederix, H.,

992

LaFemina, P., Cardona-Piedrahita, L., Lizarazo, S., Peláez-Gaviria, J.-R., Díaz-Mila, F., Bohórquez-

993

Orozco, O., Giraldo-Londoño, L., Corchuelo-Cuervo, Y., 2018. Crustal deformation in the northern

994

Andes

995

https://doi.org/10.1016/j.jsames.2018.11.002

Mt.

area,

Islands,

A

forearc,

–

A

NE

Spain).

geomorphological

Sila

new

Croatia.

Massif,

GPS

Geomorphology

approach.

Calabria,

velocity

Geomorphology

Glob.

southern

field.

J.

132–155.

102,

Planet.

Italy.

263,

Change

Am.

South

J.

Sci.

Am.

189–203.

90–91,

304,

58–72.

559–589.

Earth

Sci.

29

996

Mora-Páez, H., Mencin, D.J., Molnar, P., Diederix, H., Cardona-Piedrahita, L., Peláez-Gaviria, J.R.,

997

Corchuelo-Cuervo, Y., 2016. GPS velocities and the construction of the Eastern Cordillera of the

998

Colombian Andes. Geophys. Res. Lett. 43, 8407–8416. https://doi.org/10.1002/2016GL069795

999

Mora, A., Parra, M., Strecker, M.R., Kammer, A., Dimaté, C., Rodríguez, F., 2006. Cenozoic

1000

contractional reactivation of Mesozoic extensional structures in the Eastern Cordillera of Colombia.

1001

Tectonics 25, 1–19. https://doi.org/10.1029/2005TC001854

1002

Osorio, J., Hernández, C., Torres, E., Botero, P., 2008. Modelo geodinámico del Macizo de

1003

Santander. Intern. Rep. INGEOMINAS 150.

1004

Ouimet, W.B., Whipple, K.X., Granger, D.E., 2009. Beyond threshold hillslopes: Channel

1005

adjustment to base-level fall in tectonically active mountain ranges. Geology 37, 579–582.

1006

https://doi.org/10.1130/G30013A.1

1007

Oviedo-Reyes, J.A., 2015. Geomorfología Tectónica del Sistema de Fallas del Zulia en el flanco

1008

occidental del Sinclinal del Zulia, Norte de Santander – Colombia. Diss. thesis.

1009

Paris, G., Machette, M.N., Dart, R.L., Haller, K.M., 2000. Map and Database of Quaternary faults

1010

and folds in Colombia and its offshore regions.

1011

Paris, G., Romero, R., 1994. Fallas Activas en Colombia. Bol. Geol. 34, 3-26.

1012

Pérez-Peña, J.V., Azor, A., Azañón, J.M., Keller, E.A., 2010. Active tectonics in the Sierra Nevada

1013

(Betic Cordillera, SE Spain): Insights from geomorphic indexes and drainage pattern analysis.

1014

Geomorphology 119, 74–87. https://doi.org/10.1016/j.geomorph.2010.02.020

1015

Pérez-Peña, J. V., Al-Awabdeh, M., Azañón, J.M., Galve, J.P., Booth-Rea, G., Notti, D., 2017.

1016

SwathProfiler and NProfiler: Two new ArcGIS Add-ins for the automatic extraction of swath and

1017

normalized

1018

https://doi.org/10.1016/j.cageo.2016.08.008

1019

Ramírez-Herrera, M.T., 1998. Geomorphic assessment of active tectonics in the acambay graben,

1020

Mexican

1021

https://doi.org/10.1002/(SICI)1096-9837(199804)23:4<317::AID-ESP845>3.0.CO;2-V

1022

Rodríguez, L., Diederix, H., Torres, E., Audemard, F., Hernández, C., Singer, A., Bohórquez, O.,

1023

Yepez, S., 2018. Identification of the seismogenic source of the 1875 Cucuta earthquake on the

1024

basis of a combination of neotectonic, paleoseismologic and historic seismicity studies. J. South

1025

Am. Earth Sci. 82, 274–291. https://doi.org/10.1016/j.jsames.2017.09.019

river

volcanic

profiles.

belt.

Earth

Comput.

Surf.

Process.

Geosci.

Landforms

104,

135–150.

23,

317–332.

30

1026

Rossetti, D.F., Alves, F.C., Valeriano, M.M., 2017. A tectonically-triggered late Holocene seismite in

1027

the

1028

https://doi.org/10.1016/j.sedgeo.2017.07.003

1029

Ruszkiczay-Rüdiger, Z., Fodor, L., Horváth, E., Telbisz, T., 2009. Discrimination of fluvial, eolian

1030

and neotectonic features in a low hilly landscape: A DEM-based morphotectonic analysis in the

1031

Central

1032

https://doi.org/10.1016/j.geomorph.2008.08.014

1033

Sarmiento-Rojas, L.F.F., Van Wess, J.D.D., Cloetingh, S., 2006. Mesozoic transtensional basin

1034

history of the Eastern Cordillera, Colombian Andes: Inferences from tectonic models. J. South Am.

1035

Earth Sci. 21, 383–411. https://doi.org/10.1016/j.jsames.2006.07.003

1036

Schwanghart, W., Scherler, D., 2014. Short Communication: TopoToolbox 2 - MATLAB-based

1037

software for topographic analysis and modeling in Earth surface sciences. Earth Surf. Dyn. 2, 1–7.

1038

https://doi.org/10.5194/esurf-2-1-2014

1039

Scotti, V.N., Molin, P., Faccenna, C., Soligo, M., Casas-Sainz, A., 2014. The influence of surface

1040

and tectonic processes on landscape evolution of the Iberian Chain (Spain): Quantitative

1041

geomorphological

1042

https://doi.org/10.1016/j.geomorph.2013.09.017

1043

SGC, 2015. Geological Map of Colombia 2015 Edition. 1:1.000.000. Compiled by Gómez, M.,

1044

Montes, M., Nivia, A., Diederix, H. Digital Edition.

1045

Silva, P.G., Goy, J.L., Zazo, C., Bardají, T., 2003. Faulth-generated mountain fronts in southeast

1046

Spain: Geomorphologic assessment of tectonic and seismic activity. Geomorphology 50, 203–225.

1047

https://doi.org/10.1016/S0169-555X(02)00215-5

1048

Siravo, G., Fellin, M.G., Faccenna, C., Maden, C., Gaia, S., Fellin, M.G., Faccenna, C., Maden, C.,

1049

2019. Transpression and the build-up of the Cordillera: the example of the Bucaramanga fault

1050

(Eastern

1051

https://doi.org/10.1144/jgs2019-054

1052

Strahler, A.N., 1952. Hypsometric (Area - Altitude) Analysis of Erosional Topography. Geol. Soc.

1053

Am. Bull. 63, 1117–1142. https://doi.org/10.1130/0016-7606(1952)63

1054

Struth, L., Babault, J., Teixell, A., 2015. Drainage reorganization during mountain building in the

1055

river system of the Eastern Cordillera of the Colombian Andes. Geomorphology 250, 370–383.

1056

https://doi.org/10.1016/j.geomorph.2015.09.012

southern

Amazonian

Pannonian

Basin,

analysis

Cordillera,

lowlands,

and

Colombia).

Brazil.

Hungary.

Sediment.

Geomorphology

geochronology.

J.

Geol.

Geol.

Soc.

104,

Geomorphology

London.

358,

13,

70–83.

203–217.

206,

37–57.

jgs2019-054.

31

1057

Struth, L., Teixell, A., Owen, L.A., Babault, J., 2017. Plateau reduction by drainage divide migration

1058

in the Eastern Cordillera of Colombia defined by morphometry and10Be terrestrial cosmogenic

1059

nuclides. Earth Surf. Process. Landforms 42, 1155–1170. https://doi.org/10.1002/esp.4079

1060

Taboada, A., Rivera, L.A., Fuenzalida, A., Cisternas, A., Philip, H., Bijwaard, H., Olaya, J., Rivera,

1061

C., 2000. Geodynamics of the northern Andes: Subductions and intracontinental deformation

1062

(Colombia). Tectonics 19, 787–813. https://doi.org/10.1029/2000TC900004

1063

Telbisz, T., Kovács, G., Székely, B., Szabó, J., 2013. Topographic swath profile analysis: a

1064

generalization and sensitivity evaluation of a digital terrain analysis tool. Zeitschrift für Geomorphol.

1065

57, 485–513. https://doi.org/10.1127/0372-8854/2013/0110

1066

Thomas, W.A., 1990. Controls on locations of transverse zones in thrust belts. Eclogae geol. Helv.

1067

83/3, 727–744. https://doi.org/10.5169/seals-166611

1068

Tikoff, B., Teyssier, C., 1994. Strain modeling of displacement-field partitioning in transpressional

1069

orogens. J. Struct. Geol. 16, 1575–1588. https://doi.org/10.1016/0191-8141(94)90034-5

1070

Van der Hammen, T., Hooghiemstra, H., 1996. The El Abra Estadial, a younger dryas equivalent in

1071

Colombia. Quat. Sci. Rev. 14, 841–851.

1072

van der Lelij, R., Spikings, R., Mora, A., 2016. Thermochronology and tectonics of the Mérida

1073

Andes

1074

https://doi.org/10.1016/j.lithos.2016.01.006

1075

Velandia, F., 2005. Interpretación de transcurrencia de las fallas Soapagá y Boyacá a partir de

1076

imágenes Landsat TM. Bol. Geol. 27 (1), 81–94.

1077

Velandia, F., Doctoral Dissertation 2017. Cinemática de las fallas mayores del Macizo de

1078

Santander - Énfasis en el modelo estructural y temporalidad al sur de la Falla De Bucaramanga.

1079

Universidad Nacional de Colombia, 222 pp.

1080

Velandia, F., Bermúdez, M.A., 2018. The transpressive southern termination of the Bucaramanga

1081

fault (Colombia): Insights from geological mapping, stress tensors, and fractal analysis. J. Struct.

1082

Geol. 115, 190–207. https://doi.org/10.1016/J.JSG.2018.07.020

1083

Ward, D., Goldsmith, R., R, J., A, C., Restrepo, H., Gómez, E., 1973. Geología de los

1084

Cuadrángulos H-12, Bucaramanga y H-13, Pamplona, Departamento de Santander. Boletín

1085

geológico 21, 1–132.

1086

Whipple, K.X., 2009. The influence of climate on the tectonic evolution of mountain belts. Nat.

1087

Geosci. 2, 97–104. https://doi.org/10.1038/ngeo413

and

the

Santander

Massif,

NW

South

America.

Lithos

248–251,

220–239.

32

1088

Whipple, K.X., 2004. Bedrock Rivers and the Geomorphology of Active Orogens. Annu. Rev. Earth

1089

Planet. Sci. 32, 151–185. https://doi.org/10.1146/annurev.earth.32.101802.120356

1090

Whipple, K.X., DiBiase, R.A., Crosby, B.T., 2013. Bedrock Rivers, Treatise on Geomorphology.

1091

Elsevier Ltd. https://doi.org/10.1016/B978-0-12-374739-6.00254-2

1092

Whipple, K.X., Tucker, G.E., 1999. Dynamics of the stream-power river incision model: Implications

1093

for height limits of mountain ranges, landscape response timescales, and research needs. J.

1094

Geophys. Res. Solid Earth 104, 17661–17674. https://doi.org/10.1029/1999JB900120

1095

Whittaker, A.C., Attal, M., Cowie, P.A., Tucker, G.E., Roberts, G., 2008. Decoding temporal and

1096

spatial patterns of fault uplift using transient river long profiles. Geomorphology 100, 506–526.

1097

https://doi.org/10.1016/j.geomorph.2008.01.018

1098

Whittaker, A.C., Boulton, S.J., 2012. Tectonic and climatic controls on knickpoint retreat rates and

1099

landscape

1100

https://doi.org/10.1029/2011JF002157

1101

Willett, S., 1999. Orogeny and orography: The effects of erosion on the structure of mountain belts.

1102

J.

1103

https://doi.org/https://doi.org/10.1029/1999JB900248

1104

Willingshofer, E., Sokoutis, D., Burg, J.P., 2005. Lithospheric-scale analogue modelling of collision

1105

zones

1106

https://doi.org/10.1144/GSL.SP.2005.243.01.18

1107

Wobus, C., Whipple, K.X., Kirby, E., Snyder, N., Johnson, J., Spyropolou, K., Crosby, B., Sheehan,

1108

D., 2006. Tectonics from topography: Procedures, promise, and pitfalls, in: Special Paper 398:

1109

Tectonics, Climate, and Landscape Evolution. Geological Society of America, pp. 55–74.

1110

https://doi.org/10.1130/2006.2398(04)

1111

Yarce, J., Monsalve, G., Becker, T.W., Cardona, A., Poveda, E., Alvira, D., Ordoñez-Carmona, O.,

1112

2014. Seismological observations in Northwestern South America: Evidence for two subduction

1113

segments, contrasting crustal thicknesses and upper mantle flow. Tectonophysics 637, 57–7.

1114

https://doi.org/10.1016/j.tecto.2014.09.006

1115

Fig. captions

1116

Fig. 1 (a) Shaded relief map of the study area with main rivers; (b) Inset on the right shows the

1117

regional location of the study area within the Northern Andes. SNSM = Sierra Nevada de Santa

1118

Marta; PR = Perijá Range; SP = Swath profile. Fault mapping from Velandia (2017)

response

Geophys.

with

a

times.

J.

Res.

pre-existing

Geophys.

Earth

weak

zone.

Res.

Surf.

Geol.

Soc.

Earth

Surf.

104,

Spec.

Publ.

117,

1–19.

28957–28981.

243,

277–294.

33

1119

Fig. 2 Generalized geological map of the study area with main structures within the SM and

1120

surrounding areas. (A) Quaternary sediments; (B) Neogene; (C) Paleogene; (D) Cretaceous; (E)

1121

Jurassic; (F) Devonian-Permian sedimentary rocks; (G) Jurassic rhyolites; (H) Jurassic intrusive

1122

rocks; (I) Paleozoic metasedimentary rocks; (J) Ordovician granites; (K) Orthogneisses; (L)

1123

Ordovician schists; (M) Precambrian (?) gneisses. Modified after SGC (2015)

1124

Fig. 3 Regional rainfall patterns and shallow seismicity of the SM and surrounding areas. Rainfall

1125

data obtained from the Tropical Rainfall Measuring Mission (TRMM) and modified after Bookhagen

1126

and Strecker (2008). MAR = mean annual rainfall. Study zones and watersheds (yellow polygons)

1127

are also presented in this figure, see text for further details

1128

Fig. 4 Regional swath profile across the SM with 230 km in length and 20 km width. See the

1129

location in Fig. 1

1130

Fig. 5 Swath profiles in the northern SM showing the regional correlation between topography, local

1131

relief, and faulting. The swaths are 90 km in length and 10 km width. The faults indicated in these

1132

profiles are Bucaramanga (1), Villa Caro (15), Guamalito (16), Haca (17), El Tarra (18), San Jacinto

1133

(19) faults. See the location in Fig. 1

1134

Fig. 6 Swath profiles in the central SM showing the regional correlation between topography, local

1135

relief, and faulting. The swaths are 90 km in length and 10 km width. The faults indicated in these

1136

profiles are Bucaramanga (1), Sevilla (2), Río Charta (3), Labateca (6), Chinácota (7), Morro Negro

1137

(8), Río Sulasquilla (9), Río Cucutilla (10), Río Suratá (11), Lebrija (12), MMFS (14), and Guamalito

1138

(16) faults. See the location in Fig. 1

1139

Fig. 7 Maps of (a) mean slope, (b) slope variability, (c) local relief, and (d) hypsometric integral of

1140

the SM and surrounding areas. Note the low values in all metrics at the Berlín Plateau and the

1141

Ocaña-Ábrego zone. Reference sites are the same as in Fig. 1

1142

Fig. 8 Filtered topography in the (a) short and (b) long-wavelength of the study area. See text for

1143

further details

1144

Fig. 9 Normalized river profiles for some basins in zones N1, N2, and C1. See Fig. 3 for the location

1145

of the mentioned zones and Table 1 for the metrics

1146

Fig. 10 Normalized river profiles for some basins in zones S1 and S2. See Fig. 3 for the location of

1147

the mentioned zones and Table 1 for the metrics

1148

Fig. 11 Hypsometric curves for selected watersheds. Note the southward lowering in the HI values

1149

Fig. 12 (a) ksn map of the study area. (b) Distribution of the ksn index at the Ocaña-Ábrego zone.

1150

The white arrow shows the reversal of the Algodonal River. See text for the explanation; (c)

1151

Distribution of the ksn index at the Berlín Plateau and surrounding areas. Note the high values of the

34

1152

index at the upper reaches of the Cáraba River, which is strongly incising the low relief area. BuF=

1153

Bucaramanga Fault, GuF = Guamalito Fault, MMFS = Mutiscua-Las Mercedes Fault System. AFT =

1154

Apatite Fission Tracks.

1155

Fig. 13 Along-strike plot of the Hi and Vf indices for the studied watersheds showing a differentiate

1156

landscape evolution between the northern and southern areas

1157

Fig. 14 Linear regression plots that correlate the mean basin metrics with the precipitation data

1158

(MAP) of basins draining the western piedmont of the SM. The table in the bottom right presents the

1159

results of the KS test for each index. Please refer to the text for more details

1160

Fig. 15 Panoramic views of the Berlín Plateau (a, b); (c) Valley of the Caraba River; (d) Strath

1161

terraces on the right bank of the Cáchira River; (e) Panoramic view of the low-relief Ocaña-Ábrego

1162

zone; (f) Badlands related to the Algodonal Formation within the Ocaña-Ábrego zone

1163

Table caption

1164

Table 1 Geomorphic indices of the studied basins. See text for abbreviations.

Area (km²)

Mea n relief (m)

Ebulk (x10 m³/km² )

B01

35.2

1094

188.76

B02

34.5

916

169.02

B03

89.7

1028

301.20

B04

6.2

577

74.41

52.4

882

182.92

B06

61.4

900

123.10

B07

8.7

1075

128.96

B08

16.9

1060

168.25

B09

12.8

1040

115.46

B10

47.7

882

104.62

B11

36.1

933

146.91

7.1

355

49.71

B13

44.4

1192

139.50

B14

79.3

1070

87.39

Drainag e basin

B05

B12

Zon e

N1

N2

HI 0.3 5 0.3 3 0.3 7 0.3 4 0.4 1 0.4 4 0.4 5 0.5 4 0.5 4 0.2 8 0.3 1 0.4 2 0.4 6 0.4

Cf (%) 41.6 1 32.0 1 34.0 2 21.1 1 25.6 6 25.6 6 19.9 7 25.2 6 3.88 49.3 5 49.2 1 31.2 2 36.6 7 44.3

Max C

Lma x

Mean ksn

0.379

0.278

94.49

0.28

0.38

86.36

0.27

0.33

116.2 7

0.222

0.486

47.59

0.21

0.29

0.253

0.451

0.158

0.553

0.206

0.318

0.074

0.427

0.402

0.325

72.86

0.422

0.369

81.46

0.255

0.412

34.50

0.271

0.506

0.358

0.286

100.6 7 106.3 4 130.0 3 136.2 1 156.6 8

145.3 0 120.2

Vf

Bs

0.6 4 1.0 9 0.8 3 0.2 4 2.1 7 0.2 4 0.3 7 0.3 2 0.2 9 0.3 4 0.3 2 1.4 8 1.2 2 0.2

3.46 3 3.08 9 1.38 0 1.85 3 1.78 0 1.26 4 2.13 2 1.41 4 1.11 8 1.34 6 1.44 9 3.65 6 1.50 7 2.32

35

B15

72.5

1013

70.37

B16

23.0

712

123.43

B17

31.0

956

199.83

B18

33.3

952

182.10

B19

52.8

958

253.66

B20

30.7

973

241.56

B21

24.3

873

122.19

B22

38.7

1179

110.04

B23

39.3

1049

124.64

B24

20.4

998

110.10

B25

58.9

1108

74.93

B26

16.8

794

141.62

B27

132. 6

1266

68.75

B28

27.3

737

90.61

B29

91.9

1405

148.93

23.5

972

25.64

B31

56.0

1526

127.92

B32

24.2

1658

183.62

B33

10.5

1400

77.65

B34

36.0

1249

69.40

B35

99.3

1108

74.46

1075

362.01

1153

535.64

B30

C1

110. 9 451. 4

B36 B37 B38

6.5

529

68.55

B39

37.8

915

196.03

B40

88.1

1014

266.67

B41

68.0

998

76.66

S1

1 0.4 4 0.2 6 0.3 7 0.3 9 0.4 5 0.4 4 0.3 3 0.5 0 0.5 4 0.5 1 0.4 8 0.3 1 0.3 9 0.4 0 0.4 7 0.3 4 0.4 5 0.4 3 0.4 6 0.3 7 0.4 8 0.4 9 0.4 6 0.4 7 0.4 2 0.4 0 0.4 6

4 30.2 2 43.6 9 19.5 6 25.3 5 16.5 0 20.3 9 39.2 1 32.4 0 11.9 8 16.4 6 21.2 4 44.9 2 17.7 0

3 124.0 4

0.254

0.443

0.349

0.29

35.62

0.149

0.278

94.55

0.225

0.447

94.45

0.136

0.576

0.175

0.478

0.309

0.282

0.284

0.373

0.097

0.4

0.181

0.204

0.194

0.302

0.361

0.314

39.23

0.201

0.522

155.7 4

n/a

n/a

64.81

0.147

0.416

174.8 5

0.284

0.263

96.20

0.325

0.349

0.238

0.435

-5.77

n/a

n/a

38.1 1

0.277

0.212

3.91

0.057

0.412

-3.02 19.3 4 33.7 0 40.5 7 30.2 0

10.4 7 34.0 3 25.1 4

0.111

0.451

0.274

0.38

0.233

0.506

9.04

0.116

0.616

0.207

0.412

0.175

0.255

24.9 4 21.5 9

123.4 3 104.6 4 56.05 142.4 3 132.9 9 114.6 2 126.9 3

228.6 1 243.9 8 151.5 7 139.1 1 139.8 0 133.9 1 155.5 4 56.62 106.2 9 112.1 9 107.3 0

1 0.5 6 0.4 7 1.0 7 0.5 0 0.9 9 1.7 0 2.3 0 0.2 1 0.3 7 0.1 4 0.6 0 0.9 2 0.6 2 1.3 1 0.1 1 0.4 8 0.7 3 0.4 2 0.5 5 0.1 1 0.3 9 0.5 1 1.1 3 0.6 4 0.7 4 2.2 7 0.1 2

7 1.62 3 1.41 5 1.98 1 3.26 3 2.57 3 2.39 9 2.20 4 1.89 5 2.03 2 2.46 0 1.72 4 1.94 1 1.44 2 1.72 4 1.19 9 2.99 1 1.34 6 1.87 6 2.46 1 1.85 0 2.11 3 2.00 0 1.70 5 2.31 8 2.63 1 2.64 5 2.34 4

36

B42

20.8

1088

132.59

B43

315. 8

1233

21.19

B44

72.7

971

24.03

B45

45.5

902

95.25

B46

11.4

639

78.31

B47

7.6

769

61.48

B48

170. 9

1020

350.55

B49

22.5

1058

171.08

B50

32.4

1079

99.60

1202

535.27

1223

373.80

8.9

860

77.85

46.1

1163

185.54

B55

5.6

931

87.26

B56

31.3

1206

183.29

B57

77.0

1000

52.45

473. 1 193. 9

B51 B52 B53 B54 S2

0.4 4 0.5 3 0.4 3 0.4 3 0.4 2 0.4 9 0.4 8 0.4 9 0.4 5 0.5 0 0.5 0 0.4 8 0.4 8 0.4 9 0.4 8 0.5 6

19.5 7 33.9 2 30.4 3 32.2 9 35.5 8 -3.81

125.7 2 185.8 4 118.4 7 108.0 1

0.176

0.243

0.261

0.314

0.267

0.314

0.29

0.212

0.29

0.271

54.62

n/a

n/a

63.50

0.191

0.106

0.214

0.29

0.249

0.451

0.305

0.318

0.215

0.404

0.138

0.612

1.53

0.035

0.714

17.5 6

0.161

0.271

8.00

0.082

0.537

7.24

0.119

0.161

17.7 7 21.8 5 29.4 0 34.0 2 26.0 2 11.7 3

134.0 1 114.7 0 110.0 5 180.1 1 183.7 7 114.2 3 132.7 1 120.4 0 165.1 1 130.4 3

0.5 5 0.1 9 0.2 6 0.3 7 0.2 9 0.1 7 0.3 8 0.1 2 0.1 1 0.1 9 0.1 8 0.2 1 0.4 8 0.0 6 0.1 8 0.0 5

2.49 7 1.53 3 2.97 5 1.46 5 2.43 6 2.95 8 2.09 9 1.38 0 2.48 1 1.74 4 1.74 1 1.71 1 1.74 5 2.69 7 2.81 8 2.09 1

1165

37

73°0'W

8°20'N

8°0'N

7°40'N

72°30'W

7°0'N

73°30'W

72°30'W

a

ksn 0.0 - 53

8°40'N

128 - 216

0

Fig. 12b 40 km

20

8°20'N

bb

378 - 811

8°0'N

MM FS

7°40'N 73°30'W

c

20 km

Knickpoint

0

10

20 km

6°40'N

AFT symbol coding

Mora et al., 2015

Chitagá River

BuF

BuF

7°0'N

Labateca Block

Vetas High

GuF

10

7°20'N

MM FS

Capture knickpoint? Algodonal River

0

216 - 378

Fig. 12c

6°40'N

53 - 128

Caraba River

Berlín Plateau

van der Lelij et al., 2016

Amaya et al., 2017

AFT color coding Pleistocene Pliocene Late Miocene

Early Miocene Oligocene Eocene

Mean basin gradient

1500 1000 500 0 1000

1 0.8 0.6 0.4 0.2 0 1000

2000

3000 MAP (mm)

4000

2000

300

3000 MAP (mm)

4000

200 100

2000

3000 MAP (mm)

4000

3.00

0 1000

2000

3000 MAP (mm)

4000

Metric

R²

p-value

Mean basin relief

0.09

0.01

Mean basin gradient 0.118

0.005

Mean precipitation (mm/year) Gráfico de

Vf

2.00 1.00

0.00 1000

0.70 0.60 0.50 0.40 0.30 0.20 1000

Mean ksn

Mean basin relief (m) HI

2000

2000

3000 MAP (mm)

4000

HI

0.06

0.036

Mean ksn

0.023

0.133

Vf

0.003

0.279

a

b

c

d

e

f

Ábrego

Berlín Plateau

73°0'W

72°30'W

a

b Ocaña 1961

8°40'N

Catatumbo Basin

9

Panamá Arc Nazca Plate

13

Guamalito

Caribbean SNSM Plate

PR

Mérida Andes

Northern Andes

8°40'N

73°30'W

Amazonian Craton

Aguachica

Ocaña

Filo Orocué

7°40'N 7°20'N

31 Reference sites

12

La Esperanza 4 SP

Cúcuta Zone

7 Cáchira High

5 SP

Cúcuta 1875

6

Páramo de Guerrero

5

Mérida Andes

Arboledas 1950

El Playón

10 Rionegro

14

Bucaramanga 6 SP

Vetas High

2 4 11

Pamplona 1796 Pamplona 1644

3

Berlín Plateau -G SP

1. Algodonal River 2. Suratá River 3. Chitagá River 4. Tona River 5. Pamplonita River 6. Peralonso River 7. Sardinata River 8. El Tarra River 9. El Carmen Creek 10. Negro River 11. Frío River 12. Cáchira River 13. Catatumbo River 14. Lebrija River

0 73°30'W

8°0'N

8

3 SP

Middle Magdalena Valley

7°0'N

Filo El Romero Ábrego

73°0'W

7°40'N

1

7°20'N

8°0'N

2 SP

Elevation (m) 4537

8°20'N

Filo Jaramillo

1 SP

7°0'N

8°20'N

El Carmen

25 72°30'W

50 km

73°0'W

72°30'W

Serranía de Perijá

Key Catatumbo Basin

8°40'N

19 Guamalito

18

B

F

J

C

G

K

D

H

L M

Covered fault Reverse fault

Ábrego

16

15

14

Filo Orocué

Reference sites 1. Bucaramanga Fault 2. Sevilla Fault La Esperanza 3. Río Charta Fault 4. Chitagá Fault 5. Chucarima Fault 6. Labateca Fault El Playón 7. Chinácota Fault 12 8. Morro Negro Fault 9. Río Sulasquilla Fault 10. Río Cucutilla Fault Rionegro 11. Río Suratá Fault 12. Lebrija Fault 13. Suárez Fault Bucaramanga 14. Mutiscua-Las Mercedes Fault 15. Villa Caro Fault 16. Guamalito Fault 17. Haca Fault 13 18. El Tarra Fault 19. San Jacinto Fault 20. Zulia Fault System 73°30'W

Left-lateral fault

8°0'N

Middle Magdalena Valley

Righ-lateral fault

17

Ocaña

Cúcuta Zone

20

a óF co n o B

st Sy ult

em

7°40'N

Aguachica

8°20'N

Fault

9

10

8

Pamplona Indenter

Pamplona

11

1

6

Labateca Block

3

2

7

4

5

0 73°0'W

7°20'N

8°0'N 7°40'N 7°20'N

I

Faults

1

7°0'N

E

7°0'N

8°20'N

El Carmen

A

8°40'N

73°30'W

25 72°30'W

50 km

73°0'W

8°40'N

Zone N1

72°30'W

Catatumbo Basin TRMM MAR (mm) 4576

8°40'N

73°30'W

Reference sites

Zone N2 Northern Santander Massif

8°20'N

8°20'N

168

Cúcuta Basin

Central Santander Massif

7°20'N

in oma

Left-lateral fault

ja D

Righ-lateral fault

Zone S1

Berlín Plateau

Covered fault Reverse fault

Zone S2 73°30'W

Pamplona Indenter

Vetas High

ri Leb

Legend Faults

7°0'N

7°40'N

Middle Magdalena Valley

7°20'N

Páramo de Guerrero

0 73°0'W

20

40 km 72°30'W

7°0'N

7°40'N

Zone C1

Fault

8°0'N

8°0'N

Ocaña-Ábrego Zone

NE

SW 2500 (a) SP1 Elevation (m)

2000 1500

1500

1000

1000

500

Magdalena Valley

500

1

1.0

19

16

0

0.5 0.0

Local relief (m)

Filo Jaramillo Guamalito

THi*

2500 (b) SP2

1500

1000

1000

500

Magdalena Valley

500 17 1

0

(c) SP3

3000

Elevation (m)

2000

18

1.0

0.5 THi* 0.0 Filo El Romero

Filo Orocué

Key

2500

16 15

Ábrego

1500

1500

1000

1000 Magdalena Valley

500

500 17

0

0

18000

1.0

16

1

15 36000

54000 Distance (m)

Local relief (m)

Elevation (m)

1500

Local relief (m)

Ocaña-Ábrego Zone

2000

0.5 THi* 72000

90000

0.0

SW

NE

4000

Páramo de Guerrero (a) SP4

3500

2500 2000 1500

1500 1000

1000

Magdalena Valley

500

500 1

0

14

16

12

1.0

Local relief (m)

Elevation (m)

3000

0.5 THi* 0.0 Vetas High

2500 (b) SP5 Key

1500

1500

1000

1000

1.0

Local relief (m)

Elevation (m)

2000

0.5

THi*

500

500 10

9 14

1

0

8

11

12

0.0 4000

Labateca Block

Berlín Plateau (c) SP6

3500

2500 2000

2000

1.0

Local relief (m)

Elevation (m)

3000

0.5

THi*

1500 1000

1000 500

7

0

12

3

2

1

6

8

0.0 0

18000

36000

54000 Distance (m)

72000

90000

73°30'W

73°0'W

72°30'W

b

7°30'N 7°0'N

Mean Slope (°) 67.9

7°0'N

7°30'N

8°0'N

8°0'N

8°30'N

8°30'N

a

0

0

25

Slope var. (°) 78.2 3.4

50 km 73°30'W

73°0'W

72°30'W

c

d

Local relief (m) 2408

HI

5

0.86 0.00

73°30'W

73°0'W

72°30'W

(a)

8°30'N 8°0'N

8°30'N

7°30'N

8°0'N F. Top. 10 km (m)

-2150 - -735

501 - 1200

-734 - -200

1201 - 2000 2001 - 3000 3001 - 4500

74°0'W

F. Top. 50 km (m)

3 - 500

7°0'N

7°0'N

7°30'N

(b)

73°30'W

-199 - 400 401 - 1000

0 73°0'W

25

50 km 72°30'W

1001 - 2150

Zone S1 1.0

1.0

Normalized elevation

1.0

0.0 B39 0.0 B40 0.0 1.0 0.0 Normalized distance

Zone S2 1.0

0.0 B52 0.0

1.0

1.0

1.0

0.0 0.0

0.0 0.0

1.0

B48 1.0

1.0

B54 1.0

0.0 0.0

B56 1.0

0.0 0.0

B51 1.0

a/A

1

0

0 Zone S1 1 B39

a/A

1

0

0

a/A

0.3

a/A

0

h/H 1

h/H 1

1

B56 HI=0.48

0.4

0

a/A

1

1

B37 HI=0.46

0

1

a/A

a/A

0.1

B48

1

B20

0

1

a/A

a/A

HI=0.44

0.2

B36

0

1

1

1

HI=0.48

0.2

B54

a/A

a/A

0

1

0

1

HI=0.49

0.2

0.1

B19

0

B40

HI=0.48

h/H 1

1

1

HI=0.45

1

a/A

0

1 HI=0.50

h/H 0.2

0

a/A

0.1

B28

HI=0.40

0.2

Zone S2 1 B52

1

HI=0.40

1

a/A

a/A

h/H

h/H 0

0

1

HI=0.42

0.3

0.1

h/H

h/H

HI=0.51

1 HI=0.39

1

0

h/H

0 Zone C1 1 B24

0.1

B18

h/H

0.1

1

h/H

1

a/A

h/H

0

B05

HI=0.41

h/H

0.1

HI=0.37

h/H

HI=0.33

1

B03

h/H

1

h/H

0 a/A Zone N2 1 B17 HI=0.37

1

B02

h/H

0.1

1

h/H

h/H

Zone N1 1 B01 HI=0.35

0.2

a/A

1

B51 HI=0.50

0

a/A

1

2

Vf

1.5 1 0.5 0

SE 0.6

0.5 0.4 Linear (Vf) Linear (HI) 0.3 Vf HI 0.2 0.1 0

HI

2.5 NW

NW

3700

Cáchira High

Local relief Max. elevation Mean elevation Min. elevation

Vetas High

SE

Berlín Plateau

Ocaña-Ábrego Zone

2800

2700 1800

1900 1000 100

Catatumbo River 35000

Cáchira River 70000

105000 Distance (m)

140000

Suratá River 175000

Caraba River 210000

900 0

Local relief (m)

Elevation (m)

4600

Zone N1 1.0

Normalized elevation

B01 0.0 1.0 0.0 Normalized distance

B02 0.0 0.0

1.0

1.0

1.0

1.0

B03 0.0 0.0

1.0

B05 0.0 0.0

1.0

Zone N2

B17 0.0 0.0

1.0

0.0 B18 0.0

1.0

1.0

1.0

1.0

1.0

0.0 B19 0.0

1.0

Zone C1 1.0

1.0

B24 0.0 0.0

1.0

B28 0.0 0.0

B36 0.0 0.0

1.0

1.0

1.0

1.0

0.0 B20 0.0

1.0

B37 0.0 0.0

1.0

Highlights

-

A DEM-based comprehensive landscape analysis of the Santander Massif and surrounding areas is presented. Quantitative and qualitative geomorphological data reflect along-strike variations in topography and recent surface uplift in the Santander Massif. The Bucaramanga Fault constitutes an active structure with higher uplift rates at central Santander Massif The relative westward motion of the Mérida Andes into the central Santander Massif controlled recent landscape evolution in this part of the Northern Andes. Northern Santander Massif records a Neogene relict landscape at the OcañaÁbrego zone with little vertical deformation.

AUTHORSHIP STATEMENT

Manuscript title: Along-strike variations in recent tectonic activity in the Santander Massif: new insights on landscape evolution in the Northern Andes All persons who meet authorship criteria are listed as authors, and all authors certify that they have participated sufficiently in the work to take public responsibility for the content, including participation in the concept, design, analysis, writing, or revision of the manuscript. Furthermore, each author certifies that this material or similar material has not been and will not be submitted to or published in any other publication before its appearance in the Journal of South American Earth Sciences. Authorship contributions Helbert García-Delgado: HGD Silvia Machuca: SM Francisco Velandia: FV Franck Audemard: FA Category 1 Conception and design of study: HGD Acquisition of data: HGD, SM Analysis and/or interpretation of data: HGD, SM, FA, FV Category 2 Drafting the manuscript: HGD, SM, FV Revising the manuscript critically for important intellectual content: HGD, SM, FV, FA Category 3 Approval of the version of the manuscript to be published (the names of all authors must be listed): HGD, SM, FV, FA Acknowledgements All persons who have made substantial contributions to the work reported in the manuscript (e.g., technical help, writing and editing assistance, general support), but who do not meet the criteria for authorship, are named in the Acknowledgements and have given us their written permission to be named. If we have not included an Acknowledgements, then that indicates that we have not received substantial contributions from non-authors. Best regards, Helbert García-Delgado Geologist – Colombian Geological Survey

Declaration of interests ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. ☐The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: