Holocene coastal evolution of the transition from transgressive to regressive barrier in southern Brazil

Catena 185 (2020) 104263

Contents lists available at ScienceDirect

Catena journal homepage: www.elsevier.com/locate/catena

Holocene coastal evolution of the transition from transgressive to regressive barrier in southern Brazil

T

⁎

L.G. Limaa, , C.K. Pariseb a

Laboratory for Studies in Geological Oceanography, Departament of Oceanography and Limnology, Federal University of Maranhao, Portugueses Ave 1966, 65080-805 Sao Luis, Brazil b Laboratory for Climate Studies and Modeling, Departament of Oceanography and Limnology, Federal University of Maranhao, Portugueses Ave 1966, 65080-805 Sao Luis, Brazil

A R T I C LE I N FO

A B S T R A C T

Keywords: Coastal barrier Ground-penetrating radar Sedimentary facies

In this study the evolution of a Holocene coastal barrier was determined based on a basal transgressive unit followed by a regressive unit. Standard penetrating test, vibrocore and ground-penetrating radar profiles were used to acquire stratigraphic data. Sedimentological, paleontological and geochronological analyses were performed to describe and interpret the sedimentary facies. The base of the Holocene record indicates the existence of pre-transgression continental and coastal environments (basal peat), which resulted from the initial flooding of the antecedent topography (Pleistocene substrate) due to rising sea levels. During this period, the continental environments were flooded by lagoon environments that occupied the landward displacement of the transgressive barrier, which had channels that connected the lagoon and the ocean. At this time, the coastal barrier had a transgressive configuration indicated by its morphology and characterized by washover fans. As the backbarrier accommodation space decreased due to the displacement of the barrier (transgressive maximum), the transition of the transgressive/regressive record began at approximately 7.200 years BP, restricting the overwash events and the dynamics of the inlets. However, before the highest level (eustatic maximum) of the Postglacial Marine Transgression (PMT) was reached, this transgressive barrier stopped its migration toward the continent, causing an inversion of the depositional record, which became a normal regression. Later, at the end of the PMT, sea levels began to fall, causing a forced regression that persists to the present day.

1. Introduction Coastal barriers are often described in the literature as having a relatively simple structure (transgressive or regressive) and are usually classified based only on their surface geomorphological characteristics. However, only the subsurface stratigraphic study of these barriers can determine their stratigraphic structure and, therefore, their transgressive and/or regressive nature. Whenever possible, an accurate identification of the nature of these deposits should consider a multidisciplinary approach (e.g., Kraft, 1971; Kraft and John, 1979). All modern coastal barrier systems originated as a result of rising sea levels during the Postglacial Marine Transgression (PMT) (Field and Duane, 1974; Swift, 1976; Swift and Thorne, 1991; Roy et al., 1994; Cowell et al., 1999). Throughout their transgressive trajectories across continental shelves, these coastal barriers occasionally became regressive (normal regression) due to a high sediment supply, decreased rates of sea level rise or even variables related to the antecedent topography

⁎

(Kraft, 1971; Belknap and Kraft, 1985; Stolper et al., 2005; Murray and Moore, 2018). This inversion of the depositional record from retrogradational (transgressive) to progradational (regressive) led to the preservation of an erosive surface (wave ravinement) between these deposits. In the Holocene, the shift of transgressive and regressive deposition in coastal barriers is found under the following conditions: 1 – The sea level is monotonically rising, as on the East Coast of the United States or on the Dutch coast (e.g., Curray et al., 1969; Dillon, 1970; Kraft et al., 1987; Beets et al., 1992; Cowell et al., 1999). 2 – Sea level rise is followed by a period of steady sea levels, as observed along Australia’s South East Coast (e.g., Thom and Roy, 1983; Thom, 1984; Roy, 1994; Roy et al., 1994; Lessa and Masselink, 2006). 3 – Sea level rise is followed by slow and progressive fall, as observed on the Brazilian coast (e.g., Dominguez and Wanless, 1991; Souza, 2005; Dillenburg et al., 2000; Dillenburg et al., 2006; Hein et al., 2012; Dillenburg et al., 2014). However, only the last condition (3) allows a detailed evaluation of

Corresponding author. E-mail address: [email protected] (L.G. Lima).

https://doi.org/10.1016/j.catena.2019.104263 Received 22 January 2019; Received in revised form 9 September 2019; Accepted 13 September 2019 0341-8162/ © 2019 Elsevier B.V. All rights reserved.

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

According to oxygen isotope stages (OIS), the older systems (Pleistocene) were estimated to have formed at approximately 400.000 years BP (stage 11), 325.000 years BP (stage 9) and 125.000 years BP (stage 5e). The modern, active system began to take form at approximately 7.000 years BP The coastal plain ranges from 15 to 100 km wide (it is 15 km in the study area) and is bordered landward by bedrock highlands. The climate is humid and temperate, characterized by warm to hot temperatures (a mean of 26 °C) in summer and cool temperatures in winter (a mean of 12 °C). Rainfall ranges from 1000 to 1500 mm and is evenly distributed throughout the year (Nimer, 1990). The prevailing wind is NE, and it changes 180° during and immediately after the passage of cold fronts (Calliari et al., 1998). These SE-SW winds are the most intense (Braga and Krusche, 2000). The southern coast of Rio Grande do Sul is oriented NE-SW and subjected to dominant swell waves approaching mainly from the SE-SW, which yield net northerly longshore sediment transport, and wind-generated waves produced by strong spring and summer NE sea breezes. The average significant wave height and period are 1 m and 10–11 s, respectively (Tozzi and Calliari, 2000). During autumn and winter storms, the wave height frequently exceeds 2 m, and storm surges can reach up to 1.3 m above the modern mean sea level (Calliari et al., 1998; Barletta and Calliari, 2001; Parise et al., 2009). Under these conditions, intensive beach erosion occurs along the southern portion of the protruding sections of the coast, producing a high concentration of heavy minerals (up to 30%) at the fore and backshore (Dillenburg et al., 2004). The coast is wave-dominated (microtidal) with semidiurnal tides that have a mean range of 0,3 m. A net northward littoral transport is evident in the coastal geomorphic features (Tomazelli and Villwock, 1992). Presentday Rio Grande do Sul beaches receive little inland sand because most of the bedload carried by the few streams and rivers that drain to the coast is trapped in lagoons and other coastal plain environments (Tomazelli et al., 1998). Because of changes in the coastline orientation (azimuth varying from 10° to 50°) and the inner shelf morphology and gradient (varying from 0,027° to 0,125°), Rio Grande do Sul beaches are exposed to different degrees of wave energy and subjected to variations

the transition between transgression/regression and the main factors that control it – sedimentary deposition and sea level variation. Thus, this condition allows the determination of an approximation of this relationship for a specific coastal region during a long period of time. This occurs due to the high preservation potential imposed by the fall of the NRM that keeps the coastal barrier intact under the context of the transgressive maximum. Three hypotheses for the transgressive/regressive inversion chronology (time) have been proposed: 1 – The inversion (or beginning of the forced regression phase) coincides with the highest sea level of the PMT, indicating an equality relation between the sedimentary deposition rates and the generation of accommodation space (deposition = accommodation). 2 – The inversion precedes the highest sea level of the PMT, indicating a period of high sedimentary deposition (deposition > accommodation), causing an initial phase of normal regression, followed by a forced regression phase (which occurs after the highest sea level of the PMT). 3 – The inversion occurs after the highest sea level of the PMT, indicating a sediment deficit (deposition < accommodation), resulting in a late forced regression stage. Thus, the present study aims to understand how sedimentary deposits and sea level variations affect the transition threshold (transgressive/ regressive) in the evolution of coastal barriers on the southern coast of Brazil.

2. Regional setting The Holocene barrier at Itapeva beach is located in Brazil’s southernmost coastal sector. This coastal sector belongs to the southern Brazilian Continental Margin, which is a rifted plate boundary formed in the Early Cretaceous. In the vicinity of Rio Grande do Sul (29°–34° south latitude) (Fig. 1), the deposition of a large quantity of post-rift, mainly clastic sediments produced a wide (100–200 km), shallow (100–140 m) and gently sloping (0,03–0,08°) continental shelf. On land, a low-relief coastal plain was formed during the Quaternary by the juxtaposition of the sedimentary deposits of four barrier/lagoon systems (Villwock et al., 1986) (Fig. 1).

Fig. 1. The location of Itapeva to Rondinha Nova beach and the general geology of the Rio Grande do Sul coast (modified from Tomazelli and Villwock, 1996). A Spot 1 image of the modern barrier surface illustrates the coastal dune system that dominates the present barrier, as it did in the past. The insets present Itapeva’s location, a cross-section showing the drill core locations and the GPR profile. 2

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

Fig. 2. Sea-level envelope and paleo-sea-level reconstructions for the Brazilian coast north of 28° (solid line and squares) and south of 28° (dashed line and circles), based on vermetid samples (taken from Angulo et al., 2006).

correlation between the geotechnical interface (deposit compaction) of the wind/beach facies and its corresponding wind/beach radar facies. In the sediment record retrieved from the surveys, 1-cm3 aliquots were collected every 20 cm of the record, totaling 40 samples that were subjected to analysis for palynomorphs and diatoms. The chemical processing of the samples followed the palynological techniques described by Faegri and Iversen (1989), adapting the cold treatment with HCl (5%) and KOH (5%). An aqueous ZnCl2 solution with a density of 2,2 g/cm3 was used to separate inorganic and organic particles. The particle size analyses were performed using a CILAS 1180 laser particle analyzer. The statistical treatment followed the techniques described by Folk and Ward (1957). The grain size mode of each sediment sample (100 grains) was classified according to the morphoscopy, adopting the Rittenhouse (1943) classification for sphericity, the Krumbein (1941) classification for roundness and the Bigarella et al. (1955) classification for surface texture. The total carbon of 82 sedimentary levels was evaluated according to the method used by Wetzel (1975). The color aspects of the sediment samples followed the parameters described by Munsell (2009). Analyses of 14C were performed using the accelerator mass spectrometry (AMS) method on 10 samples (2 organic sediment samples and 8 samples of mollusk shells in life position) at the Beta Analytic Radiocarbon Dating Laboratory in Miami, Florida, USA. Samples were calibrated following the MARINE04 (Hughen et al., 2004) and the INTCAL04 (Reimer et al., 2004) databases, interpolated according to the weighted cubic spline fit described by Talma and Voge (1993).

in longshore sediment transport (Dillenburg et al., 2000, Lima et al., 2001; Martinho et al., 2009). The current postglacial sea-level history of the Rio Grande do Sul coast extends from approximately 17.5 ka, when the sea level was approximately 130 m lower (Correa et al., 1995). Thereafter, the sea level rose at an average rate of 1.2 cm/yr, varying from 0.6 cm/yr (14–12 ka) to 1,9 cm/yr (8–6.5 ka) (Correa et al., 1995). Unfortunately, there are no reliable data on sea-level changes for the middle to late Holocene on the Rio Grande do Sul coast. However, the sea-level curves 130 km north of Rio Grande do Sul show the culmination of the PMT (approximately 6–5 ka), when the sea level reached a few meters (1–3 m) above its present level, which was followed by a slow sea-level fall (Martin et al., 2003; Angulo et al., 2006) (Fig. 2).

3. Materials and methods The present study is based on ground-penetrating radar (GPR) records, facies analyses and radiocarbon dating. The GPR records were obtained using a SIR-3000 GSSI acquisition module (Geophysical Survey Systems, Inc.) with an antenna with a center frequency of 200 MHz in a Common Offset arrangement. The geophysical record was interpreted based on the seismic stratigraphy adapted for GPR records (Neal, 2004). Guided by the GPR records, 6 standard penetration test (SPT) and 2 vibracore surveys were performed. In Brazil, the SPT technique is regulated by the NBR-6468 standard of the Brazilian Association of Technical Standards/Brazilian Civil Construction Committee (Associação Brasileira de Normas Técnicas/Comitê Brasileiro de Construção Civil - ABNT/CB) and consists of a dynamic resistance measurement combined with a survey for sediment analysis. This technique allowed great depths to be reached but in a discontinuous way; i.e., for each surveyed meter, 45 cm of intact sedimentary record (undisturbed) and 55 cm of disturbed sedimentary record (ditch sample) were obtained. Intact samples were extracted by the percussion of a falling weight (65 kg) on penetrating rods connected to a RaymondTerzaghi sampler. The penetration of this sampler provided a compaction index for the sedimentary deposit (number of strokes/sampler penetration). Disturbed samples (55 cm) were extracted by manual drilling with a drill assisted by circulation of a water and bentonite mixture. The vibracore surveys were performed by penetrating an aluminum pipe (7,5 cm in diameter and 6 m in length) with low-frequency vibration (vibration amplitude of 0.85 mm at 12,500 rpm). Positioning for both the survey and the GPR acquisition data were measured with a Leica Viva CS15 DGPS. They were correlated to the mean spreading point of the waves at Rondinha Nova beach and corrected by the tide table (DHN, 2011) for the Imbituba Port – Santa Catanina state (SC), located approximately 130 km north of the study area. GPR data were post-processed using the RADAN 6.6 and ReflexW software. The adjustment of the dielectric constant was defined by the

4. GPR records Ground-penetrating radar has been used in coastal regions to locate and identify sedimentary structures (Leatherman, 1987; Jol and Smith, 1991; Meyers et al., 1994; Bridge et al., 1995; Jol et al., 1996; Bristow et al., 2000; Anthony and Moller, 2002; Barboza et al., 2009; Dillenburg et al., 2011). Due to its non-invasive and high-resolution form of acquisition, GPR provides an often unique dataset (Neal and Roberts, 2000). When interpreting GPR data, the term radar facies is used to define repeated packages of reflectors with similar characteristics and geometries, whereas their sequence limits are determined by the termination of the reflectors. According to Van Overmeeren (1998), this definition involves the mappable differences in the reflection pattern of a GPR section, caused by tracts with structural and textural characteristics in the subsurface. Tracking the radar facies (Rf3 and Rf4) identified in the present study using the GPR method was relatively easy, mainly due to the high percentage of heavy minerals (> 3%) found in these facies horizons (e.g., Buynevich et al., 2004; Lima et al., 2013).

3

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

Fig. 3. GPR profile of the Holocene transgressive/regressive barrier at Itapeva. In detail, profiles A and B at the intersection of geological surveys. To the left of the surveys is the geotechnical profile (dynamic resistance to sampler penetration) in knots. (For the location, see Fig. 1).

deposition of washover fans entering the lagoon body in the backbarrier (Schwartz, 1982; Murakoshi and Masuda, 1991; Anthony and Moller, 2002; Neal et al., 2003) (Figs. 3 and 4).

4.1. Radar facies description 4.1.1. Rf1 – Transgressive dunes This radar facies is defined by high-amplitude subhorizontal reflectors that are laterally continuous and concordant and by low-amplitude and high-angle (15–20°) wavy reflectors with short and sometimes concave landward clinoforms. In the vicinity of the lagoon margin, these clinoforms collapse or dissipate, and only a wavy and morphologically undefined profile remains (Figs. 3 and 4).

4.1.5. Rf5 – Shoreface This radar facies comprises discontinuous, wavy, low-amplitude and low-angle (3–5°) seaward reflectors. They appear distinct from Rf3 mainly due to the shorter continuity of the reflectors. At the lower limit of this unit, the GPR signal is attenuated due to the presence of fine sediments in its composition (Figs. 3 and 4).

4.1.2. Rf2 – Foredune This radar facies comprises slightly wavy discontinuous reflectors of low amplitude and high angle (10°), with short, concordant and preferentially seaward clinoforms. Its reflectors do not extend more than 5 m, and a concordant stacking in a progradational seaward pattern is common (Figs. 3 and 4).

4.2. Retrogradational radar facies The GPR profiling was performed at the rear of the coastal barrier, close to the lagoon margin (Fig. 3). The topography of this profile is flat enough that topographic correction is unnecessary. This profile records the interface between the Rf4 and Rf3 radar facies (Fig. 4), which delimit a wave ravinement surface (RS) sensu Swift (1968). This surface is interpreted as the threshold between a transgressive phase (lower limit) and a regressive phase (upper limit) of the coastal barrier; i.e., it represents the interface between these two distinct (inverse) sedimentary depositional patterns. The origin of the RS is a result of the transgressive phase of the coastal barrier, when this erosive surface was still active, advancing landward and truncating preexisting deposits (washover fans - Rf4) due to coastline recession. The recording of this RS translation (migration) is evidenced in the truncated sets of Rf4 reflectors (Figs. 3 and 4). Rf4 reflectors, in turn, illustrate the main morphological aspect of a transgressive barrier, which is the deposition of washover fans. These depositional tracts always occur at the rear of coastal barriers, and the dip angle of their reflectors is used as an indicator of the water level position when the washover fans were

4.1.3. Rf3– Backshore/foreshore This radar facies consists of laterally continuous, symmetrical and concordant reflectors that extend for 30 m or more. These are highamplitude, sub-planar and slightly wavy seaward-dipping reflectors, with dip angles of 3–5°. This set of reflectors has an undefined contact with the upper (Rf2 and Rf1) and lower (Rf5) radar facies (Figs. 3 and 4). 4.1.4. Rf4 – Washover This radar facies contains continuous high-amplitude and concordant reflectors, with landward dip and toplap and downlap terminations. The low dip angles (1–5°) exhibit a slightly concave and wavy geometry, indicating deposition on areas emerging from the coastal barrier, whereas reflectors with higher angle (10°) indicate the distal 4

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

Fig. 4. Interpretation of GPR profiles showing the intersection of lithofacies (cores) with radarfacies (For the location, see Figs. 1 and 3).

point of transition between the retrogradational (transgressive) and the progradational (regressive) behavior of the coastal barrier. The continuity of these progradational reflectors is followed by a superelevation of the Rf3 radar facies, reaching the +2 m limit with respect to the relative sea level (RSL) in the IT-5 penetration survey (Figs. 3 and 4). The lower limits of the Rf3 radar facies mark the transition to the discontinuous reflectors from the shoreface (Rf5). On the Rf3 radar facies, the Rf2 radar facies exhibits partial continuity of reflectors and occupies the barrier surface in the oceanic sector, i.e., close to the current beach. This radar facies corresponds to the progradation of foredunes on the backshore/foreshore (Rf3), and its dip varies little, always following a seaward progradational pattern. This construction and the lateral addition of seaward foredunes has been described by Goldsmith (1973), Hesp (1988), Ritchie and Penland (1990), Bristow et al. (2000) and Barboza et al. (2013).

deposited (Schwartz, 1975). An abrupt geometry (high angle) of the reflection pattern points to underwater deposition reaching the backbarrier, and a smooth geometry (low angle) of the reflection pattern points to deposition in the subaerial positions of the coastal barrier. Thus, two types of deposition associated with this radar facies can be identified: Rf4 (washover fans), when the deposition reaches the backbarrier and generates high-angle reflectors, and Rf4 (typical washover), when the deposition does not reach the backbarrier and occurs only on the surface emerging from the barrier. When intercepted by the IT-3 survey, the Rf4 radar facies exhibits a discontinuous pattern of geotechnical compaction indices (Fig. 3). This pattern varies from little to very compacted, showing the washover deposition at the lagoon margin, where predominantly sandy sediments intersect layers of silty sediments. These silty sediments indicate the discontinuity of the washover fan deposition when the lagoon complex reoccupies the former positions of inactive washovers. Above the Rf4 radar facies lies the Rf1 radar facies, which corresponds to transgressive dunes that have remained secured and stabilized by both the vegetation and the moisture near the lagoon margin. In the vicinity of the lagoon margin, the typical clinoforms of this radar facies collapse or dissipate, leaving only a wavy and morphologically undefined profile. This type of tract is formed by deflating surfaces that remain after dune migration along the barrier surface and is preserved only in the vicinity of the lagoon margin (Figs. 3 and 4).

5. Depositional facies and stratigraphy The geotechnical surveys (SPT) allowed the compaction of sediments to be recorded. Thus, they were used to adjust the depth of the GPR data by correlating the compaction record of aeolian and shoreface deposits. Due to the interface between these deposits, there is an abrupt increase in the compaction index (Fig. 3, IT-4), which allowed this limit to be defined based on the change in configuration of the reflectors. Similarly, the arrangement between the records was obtained using a dielectric constant of 12. The sedimentary record of the surveys is briefly described using sedimentary criteria (lithofacies) that include geotechnical and geochronological properties.

4.3. Progradational radar facies The main architectural characteristic of the regressive (progradational) phase of the barrier is the deposition of the Rf3 radar facies, which forms the progradational stacking of backshore/foreshore clinoforms. This radar facies has reflectors whose onlap terminations are on the RS and on the shoreface facies (Rf5) (Figs. 3 and 4). The Rf3 reflectors represent the diagnostic radar facies of the progradational phase of the coastal barrier and extend continuously up to the current beach. Their landward boundary is at the interface with the RS and therefore has the truncated reflectors of Rf4. This interface is also the

5.1. Retrogradational lithofacies 5.1.1. Basal peat facies − BPF The base of the Holocene record was found in the IT-3 survey and corresponds to a well to moderately sorted and very compact 2 m-thick segment with a sandy texture (18% silt) and a dark gray color (5GY4/ 1). The base of the facies is essentially sandy, and it gradually becomes 5

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

Table 1 Ages of 14C samples. Sample/Laboratory Number

Dated Material

Depthc (m)

13

FS-17-08A/Betaa − 159104 IT-4 #21/Beta − 285324 IT-3 #20/Beta − 298863 IT-8/Beta − 298864 IT-5 #14/Beta − 310807 IT-6 #TOPO/Beta –310808 IT-6 #BASE/Beta – 310809 FS-17 #15/Beta – 310810 FS-17 #16/Beta – 310811 FS-17 #18/Beta – 310812

shell shell org. sediment org. sediment shelld shelld shelld shelld shelld shell

−6.6 −14.1 −15.5 −2.4 −11.6 −0.8 −2.2 −13.6 −14.6 −15.6

+1.3 0.0 −19.9 −21.0 +0.4 +2.0 +1.8 +1.1 +1.8 +1.9

a b c d

C/12C ratios (o/oo)

Conventional Age (14C yr BP)

Calibrated Age (yr BP)b

2.410 8.060 8.890 6.700 6.690 6.630 6.740 4.350 4.430 4.820

2.035 8.450 9.985 7.560 7.205 7.175 7.265 4.475 4.595 5.125

± ± ± ± ± ± ± ± ± ±

40 40 40 40 30 30 30 30 30 30

± ± ± ± ± ± ± ± ± ±

95 110 205 60 55 55 45 75 95 115

Beta Analytic Inc., Miami, Florida, USA. 2 sigma calibration (95% probability). Sampling depth relative to MSL. Bivalves in life position.

muddy near the top, where mud couplets are found. The fine sand grains are predominantly rounded (46–63%), with good sphericity (50–70%) and polished mamelonate (40%). A sample from the top of the facies, at a depth of −15,5 m from the RSL, indicated a volatile organic matter content of 2,9–7%, which allowed us to perform radiocarbon dating (AMS). The result was an age of 9.985 ± 205 years BP (Table 1). The basal peat facies (BPF) was sampled at three levels to perform micropaleontological analyses (Fig. 5). Interpretation: This facies is the base of the Holocene sedimentary record. It represents a flooded continental environment indicated by the dominance of opal phytoliths and palynomorphs of exclusively freshwater taxa. Combined with the age of approximately 9.985 years BP, these attributes allow them to be correlated to the BPF with basal peat environments present on the Pleistocene substrate (previous topography) during the early stages of the coastal flood that followed the PMT.

basal peats. The simultaneous presence of marine and estuarine mollusks with marine, estuarine and freshwater diatoms allows us to consider that this facies was formed in a lagoon environment (backbarrier) with a permanent connection with the ocean through one or more inlets. The marked presence of Chlorophytes and NAP-aquatics indicates the convergence of large river systems to this depositional environment, suggesting that its origin may be defined as typically estuarine. 5.1.3. Washover facies – WF The washover facies (WF) is 5–9 m thick and has a gradual contact with the ELF. The WF has a sandy composition. The sand varies from fine to very fine (97%) and is well to moderately sorted, with predominantly light gray color (5Y4/1). The sand is moderately to very compact and has heavy mineral and silt laminations. The intercalations of silt laminations reach 1–10 cm in thickness with 3,3–4,3% volatile organic matter, resulting in a large variation on the compaction of these facies (Fig. 3). In the IT-8 survey (Fig. 6), laminations of very fragmented, and highly abraded shells are found in the middle portion of the WF and cannot be identified. In the IT-4 survey, millimetric mud couplets occur associated with very fragmented, highly abraded and a little bioturbated A. brasiliana, C. protea, C. rhizophorae and O. puelchana bivalves and T. uruguaensis, A. isabellei, Arene microforis, P. uruguaensis and H. australis gastropods. This level has a large number of very fragmented and abraded Echinoidea spines as well as Cirripedia fragments (barnacles), also very abraded. There is an erosive truncation at the top of the WF, which is caused by the landward migration of the RS mapped on the profile A of the GPR section (Fig. 4). In the IT-6 survey, the Echinoidea, Mollusca and Crustacea classes are found. The remaining structures of these organisms found at the base of the WF are very fragmented, little abraded and moderately bioturbated. The mollusk specimens observed are Anadara sp., Diplodonta cf. notata, Chione paphia, Ostrea equestris, O. puelchana, Clausinella gayi, Mactra patagonica, Mactra isabelleana and Tivela sp. Among Echinoidea, regular echinoids are observed, indicated by spines of various sizes and carapace (shell) fragments with tubercles. Among irregular echinoids, the genus Mellita is identified. Crustaceans are represented only by unidentifiable Cirripedia fragments. At the −2,6 m level from the RSL, there is an interval with laminations of little fragmented, little abraded and moderately bioturbated shells, where bivalve specimens of Corbula contracta, Nucula semiornata (in life position), Mactra janeiroensis, Mactra petiti, Mactra patagonica, Amiantis purpurata, Crassostrea rhizophorae and Ostrea puelchana are identified. Among gastropods, Cylichna discus, Acteocina bullata, Acteocina lepta, Turbonilla sp., P. uruguaensis and H. australis are found. At this same level, a Nucula semiornata shell that was found in life position was subjected to 14C dating (AMS), and an age of 7.265 ± 45 years BP was obtained (Table 1). This mollusk species accounts for 80% of the total volume of macrofossils found in the IT-6 survey, and approximately

5.1.2. Estuarine/lagoon facies – ELF The estuarine/lagoon facies (ELF) occurs gradationally on the BPF, composed of fine sand at the base and poorly sorted fine silt at the top (18–86% silt), with a dark gray color (5Y2/1 to N3), a 12–20% volatile organic matter content and little compaction. No sedimentary structures are observed in this facies. At the depth of −2,4 m from the RSL, a sample of the organic sediment was subjected to 14C dating (AMS), and an age of 7.560 ± 60 years BP was obtained (Table 1). In the IT-6 survey (not shown in profile, see Fig. 1 for location), the ELF has millimetric mud couplets replete with typically estuarine mollusk shells. Regarding the taphonomic aspects, these shells are somewhat fragmented, abraded and bioturbated. Based on their composition, they resemble only three species: Anomalocardia brasiliana (in life position), Tagelus plebeius and Erodona mactroides (life position). An A. brasiliana shell found in life position at a depth of −1,2 m from the RSL was subjected to 14C dating (AMS), which indicated an age of 7.175 ± 55 years BP (Table 1). In the IT-4 survey, the base of the ELF has somewhat fragmented, abraded and bioturbated Protothaca antiqua, Heleobia australis, Rissoina sp., Parodizia uruguaensis, Anachis isabellei, Alabina cerithidioides, Turbolina uruguaensis and Architectonica nobilis gastropods. These shells occur among the bivalves Ostrea puelchana and Crassostrea rhizophorae (moderately fragmented, moderately abraded and little bioturbated) and Adrana japonensis, Crepidula protea, Pitar rostratum and Anomalocardia brasiliana. A single intact valve of C. rhizophorae found at a depth of −14,1 m from the RSL was subjected to 14C dating (AMS), and an age of 8.450 ± 110 years BP was obtained (Table 1 and Fig. 6). In the ELF facies was sampled at thirteen levels for micropaleontological analysis (Fig. 5). Interpretation: The fine sand/silt range observed along the ELF implies the development of low-energy lagoon bodies that reoccupy the 6

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

Fig. 5. Palynomorphs and siliceous elements (%) in drill cores IT-3, IT-4, and IT-8 and their respective facies. AP-Arboreal pollen; NAP-non-arboreal pollen; NAPaquatic non-arboreal pollen.

5.2. Progradational lithofacies

20–30% of them are specimens found in life position). In the surveys, the WF was sampled at nine levels for micropaleontological analysis (Fig. 5). Interpretation: Due to the predominance of sand and abraded fragments of mollusks and echinoderms, the WF seems to indicate a high-energy environment. These sediments are transported from the beach and adjacent dunes through washover fans during storms and then redeposited in the backbarrier. The palynomorphs are found only in millimetric silt couplets, reflecting the reestablishment of lagoon conditions on the newly formed washover deposits.

5.2.1. Lagoonal margin facies – LMF The lagoon margin facies (LMF) is composed of fine sand at the base, which is moderately to poorly sorted and has a light to dark gray color (5G to 5GY). Thick silt is found at the top (65% silt) and has a brownish color (5YR-10YR standard). The silt is poorly sorted, with many roots and organic material couplets that give this level 10–21,8% volatile organic matter In the IT-8 survey, the LMF was sampled at three levels for micropaleontological analysis (Fig. 5). 7

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

Fig. 6. Stratigraphic cross-section of the present Holocene barrier/lagoon system at Itapeva. (For the transect location, see Fig. 1).

articulated shell of C. contracta was subjected to 14C dating (AMS), resulting in an age of 4.475 ± 75 years BP (Table 1). Interpretation: The LSF has essentially silt depositional environments established beyond the closing depth. At the lower limits, there are residual elements of a transgressive lag embedded in the facies, where the yellowish coloration of the shells seems to indicate a certain diagenesis at the water/sediment boundary.

Interpretation: The LMF corresponds to the reworking of the WF by the action of waves in lagoon margin environments. The palynomorphs found reflect the dense paludal vegetation that occupies the margin and continues to develop up to the present day. The high frequencies of fungi indicate a high biological degradation rate imposed by the variation in the lagoon level. 5.2.2. Lower shoreface facies – LSF The silt lower shoreface facies (LSF) has a dark gray color (5Y 4/1) and is very poorly sorted and moderately compacted. Volatile organic matter occurs between 2,3 and 2,6%. Very fragmented, moderately abraded and slightly bioturbated shells occur at the base. Due to this high fragmentation, only Mactra patagonica and Mesodesma mactroides are identified. These shells are covered by iron oxide, which gives them a yellowish color. Three millimetric and disarticulated valves of M. patagonica were submitted for 14C dating (AMS), and an age of 5.125 ± 115 years BP was obtained (Table 1). Above the base level of this facies, the particle size decreases (phi 4.2), and there are fragmented and little abraded shells without bioturbation. At this level, Trachycardium muricatum, D. gemmula, Amiantis purpurata, M. mactroides and M. patagonica are identified. Two millimetric shells of M. patagonica in life position were submitted for 14C dating (AMS), and an age of 4.595 ± 95 years BP was obtained (Table 1). At this level, very fragmented pincers of crustaceans and well-preserved Cirripedia are found. At the top of this facies, the particle size analysis shows a phi value of 4,1, with the occurrence of moderately fragmented and little abraded shells with little bioturbation. Olividae and Anachis sp. gastropods are found, as well as the D. gemmula, C. contracta (in life position), Mactra petiti and M. patagonica (in life position) bivalve mollusks, which are little fragmented, abraded and bioturbated. Fragments of the Mellita sp. echinoid (sand dollar) are usually found along with many well-preserved pincers of decapod crustaceans. At this level, an

5.2.3. Upper shoreface facies − USF The upper shoreface facies (USF) is sandy and 5–7 m thick. The sand is fine to very fine with 3–15% silt. It has a greenish gray color (5Y 4/1) and is well to moderately sorted and very compact. There is a high concentration of macrofossils associated with mud couplets throughout this facies. The organic matter content of its sandy base varies from 0,5–2,3%. The lower limit of these facies is defined by relief in the compaction profile. The macrofossils present are moderately fragmented and little abraded and have no bioturbation. The shells identified are from H. australis, A. ovalis, D. gemmula, A. purpurata, M. petiti and M. patagonica, in life position, and from M. isabelleana, Ostrea sp. and C. contracta. In this facies, fragments of the irregular echinoid Mellita can be found. Among crustaceans, little fragmented and moderately abraded Cirripedia can be found. The top of the facies exhibits total carbon values lower than 0,5%, and only unidentifiable fragments are observed. These fragments were subjected to 14C dating (AMS), indicating an age of 2.035 ± 95 years BP (Table 1). Interpretation: The USF represents a high-energy environment deposited under the influence of waves above the closing depth. The taphonomic aspects of the macrofossils present in this facies indicate little reworking. 5.2.4. Foreshore/backshore facies – FBF The foreshore/backshore facies (FBF) is 3,5–4.5 m thick. Its top is 8

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

peat acumulation. The lagoon sedimentation linked to a transgressive coastal barrier began on this Pleistocene substrate. In this stratigraphic context, the BPF can be used as a reference for the previous topography (pre-Holocene) (e.g., Abbott, 1985; Belknap and Kraft, 1985; Demarest and Leatherman, 1985; Helland-Hansen and Martinsen, 1996). The particularities involving the BPF allow a regional stratigraphic correlation during the transgression, indicating the beginning of the Holocene sedimentation, as reported in several studies (e.g., Kraft, 1971; Kraft and John, 1979; Randall, 1989; Baeteman and Van Strijdonck, 1989; Beets et al., 1992). In the sequence stratigraphy, the BPF is equivalent to the continental end of the transgressive surface, free from wave ravinement or indicating a wide accommodation space during the transgression, when this facies is found below the transgressive surface (Van Wagoner et al., 1991; Emery and Myers, 1996; Samuelsberg and Pickard, 1999; Beets et al., 2003; Amorosi et al., 2005; Catuneanu, 2006). During the course of the PMT, the increased accommodation space created by rising sea levels transformed the initial paludal alluvial plain (BPF) into an estuarine/lagoon system (ELF) characterized by the presence of a channel between the lagoon and the ocean. This transformation first occurred in river valleys (depressions) and later in interfluvial and backbarrier regions (e.g., Boyd et al., 1992). The widespread preservation of phytolith aggregates found in the BPF (Fig. 5) indicates a lack of reworking and, therefore, an extensive preservation during the process of flooding by the estuarine/lagoon system (Lima and Medeanic, 2007). In the ELF, the presence of the estuary is indicated by the frequency of both freshwater (paludal) indicators (Bryophytes and Chlorophytes) and marine indicators (e.g., acritarchs, palynoforaminifera, silicoflagellates and marine diatoms, mainly Coscinodiscus) (Fig. 5). The interaction between the previous topography and the different migration rates of the transgressive barrier determined the different preservation potentials of the ELF when the RS retreated. Its greater preservation and, therefore, the larger thickness of the facies occurs near the lagoon margin. This feature is probably a result of the change in the behavior of barrier (from transgressive to regressive) during the final stages of the PMT, ending the RS migration process (Fig. 6). The evolution of this estuary (ELF) is marked a maximum percentage of silicoflagellates toward the ocean (IT-4 survey), which suggests a large penetration of marine waters into the backbarrier via inlets. This finding indicates that these channels were either more active or existed in greater numbers when compared with the late development of the ELF landward (IT-8 survey) and with the later stages of the PMT. Similar records of abundant silicoflagellates in the Holocene lagoon sediments of Rio Grande do Sul are also described by Medeanic and Corrêa (2007) and by Lima et al. (2013). This interpretation of the full connection between lagoon and ocean in the initial development stages of the ELF is a consequence of the stillrising sea levels at 8.450 ± 110 years BP, which made the adjacent coastal barrier narrower and possibly more segmented by inlets. This interpretation is also supported by the high density of benthic macrofauna in the ELF (IT-4 survey), forming a bank of C. rhizophorae oysters (dated 8.450 ± 110 years BP) due to these initial conditions of the ELF development stages (e.g., Kraft, 1971). This stratigraphic architecture indicates the essentially transgressive nature of the coastal barrier as it approaches and migrates landward. However, as the barrier stabilized near its current position to the detriment of its maximum landward advance (transgressive maximum), its connections with the ocean were closing, initiating a paludal development in the backbarrier, which is still present to this day. The transition from the estuarine to the paludal phase was established at 7.560 ± 60 years BP, when intercalations of H. australis and P. uruguaensis estuarine gastropods with C. rhizophorae end the marine evidence in the lagoon system, giving way to the dominance of Chlorophytes (Fig. 5). The agradational architecture developed from ELF facies and WF facies in their final stages of evolution indicates that the barrier stopped

characterized by the geotechnical compaction behavior (first maximum) in the surveys, whereas its base is limited by the relief in the compaction profile of the USF. This facies is sandy, with fine gray sand (5G6/1 and 5GY6/1), essentially well sorted and very compacted. Heavy mineral laminations are notably the most characteristic aspect of this facies. Interpretation: The FBF represents the high-energy environments deposited at the backshore and at the foreshore. 5.2.5. Aeolian facies – AF The Aeolian facies (AF) (dune/interdune) is sandy, and the sand is fine and well to moderately sorted, with an average of 2,4–2,6 phi. The sand is light to dark beige (10YR to 5Y) and little compacted. This facies occurs from the surface to the first maximum compaction in the SPT profile (Fig. 3). Ferruginous concretions occur near the top and merge with roots. The volatile organic matter content is 4–20% at near-surface levels and is positive for microfossils. In the surveys, the AF was sampled at eleven levels for micropaleontological analysis (Fig. 5). Interpretation: The AF represents the aeolian environments deposited in dunes and interdunes (deflation plains). Combined with the water table, the high positioning of the lagoon level conditions these environments to remain flooded during the winter due to greater local rainfall, which allows the preservation of microfossils in these sediments. 6. Discussion Within the Rio Grande do Sul Coastal Plain, the coastal barrier in Itapeva is the sector with the largest slope between continental basement rocks and the ocean. Due to this fact, there was intense river excavation in low sea-level stages. During the Last Glacial Maximum, this river excavation generated a large accommodation space that differentiate the characteristics of this coastal segment in relation to the rest of the coast (e.g., Milliman and Meade, 1983; Milliman and Syvitski, 1992; Syvitski et al., 2003). The base of the Holocene sedimentary record obtained corresponds to the BPF obtained in the IT-4 and IT-3 surveys. Its micropaleontological composition indicates a paludal origin, in which NAPaquatics, Chlorophytes, Bryophytes and freshwater Eunotia sp. diatoms are frequent (Fig. 5). These peats developed in response to rising sea levels during the PMT, which resulted in flooding by the water table of pre-transgression deposits at approximately 9.985 ± 205 years BP. These depositional environments represent the first and still continental stage (beginning of the record) of the PMT. Its continental affinity is expressed by the occurrence and diversity of phytoliths sampled in this facies (Fig. 5). The origin of this facies seems to be related to paleosols that were flooded by the elevation of the water table that followed the rising sea level. This flooding transposed/flooded environments that were formerly continental and internalized, transforming them into coastal peats in the course of the transgression. This transition is recorded by the gradual decrease in phytoliths, AP and NAP toward the top of the facies and, conversely, by a gradual increase in NAP-aquatics, Chlorophytes and Bryophytes (Fig. 5). At the southern end of Brazil, Lima et al. (2013) describe a facies that is very similar to the BPF in paleoecological, chronological and stratigraphic aspects. They define the origin of this facies as linked to the Holocene lagoon system established over the Pleistocene substrate, which underwent progressive flooding during the PMT. Although the present study did not directly intercept the Pleistocene substrate, the anomalous concentration of polished mamelonate grains recorded in the BPF may indicate the proximity of this substrate. According to Lima et al. (2007) and Lima et al. (2013), the lateral continuity of these basal peats stretches landward, covering the surface on Pleistocene barriers and remaining in constant development since its formation (9.985 ± 205 years BP) until the presente. The BPF is formed by the rise in sea level resulted in the rise in water table that provided the required anaerobic conditions for 9

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

The IT-6 survey is positioned on a washover fan remnant (WF) of approximately 1 km, which currently remains as a large geomorphological tract that enters the lagoon margin in the form of a large spit (Fig. 1). This tract represents a geomorphological inheritance of the transgressive phase of the barrier, being filled with very fragmented, slightly abraded and moderately bioturbated echinoids, mollusks and crustaceans, which indicates its oceanic origin, clearly in contrast to the low-energy depositional environment of the backbarrier. Echinoids of the genus Mellita widely distributed in the USF and LSF represent the most likely origin of the fragmented material found in the WF. Other taphonomic aspects found in the washover fans in the lagoon margin, such as the N. semiornata shells found in life position, indicate that in addition to biodetritus, the washover events dragged live specimens from the oceanic face to the backbarrier. The dating of one of these specimens indicates an age of 7.265 ± 45 years BP, which is the highest recorded in the WF with respect to the RSL (−1 m) and indicates the last penetration events of washover fans on the backbarrier. The beginning of the regressive phase of the barrier interrupted the dynamics of the washover fans, causing a recurrence of the lagoon/ estuarine depositional environments in the rear of the coastal barrier at approximately 7.175 ± 55 years BP. These environments recorded the last and highest marine/estuarine level in the backbarrier (−0,8 m with respect to the RSL), confirming that the lagoon still had a connection with the ocean at this time. The chronological similarity between the latter event and the top of the WF (7.265 ± 45 years BP) and the LSF (7.205 ± 55 years BP) indicate the correlation between the end of the transgressive phase and the beginning of the progradation of the barrier (USF). The establishment of the transgressive barrier in its terminal position probably involved an aggradational lagoon phase that finally closed the existing inlets, which cancelled the transfer of sediments along the component transverse to the coast and modified the relationship between the accommodation space and the sedimentary deposition in this coastal sector (e.g., Curray, 1964; Swift, 1975; Vail et al., 1977). Thus, as the sedimentary flows became restricted to the oceanic face of the barrier, the sediment deposition rate finally exceeded the sedimentary accommodation, triggering the beginning of the progradational phase of the barrier. This inversion of behavior (from transgressive to regressive) preceded the Holocene eustatic maximum according to the RSL curve proposed by Angulo et al. (2006) (Fig. 2). This event indicates that sedimentary deposition, now restricted to the oceanic face of the coastal barrier, began to overcome the accommodation space created by the RSL elevation rates at this time (7.265 years BP), which resulted in a condition of normal regression. This combination of regressive deposits covering transgressive deposits is not uncommon, with similar examples occurring in coastal barriers on the Australian coast (Thom, 1984; Roy, 1994; Roy et al., 1994; Cowell et al., 1995; Lessa and Masselink, 2006), on the US coast (Curray et al., 1969; Kelley et al., 2005), on the Dutch coast (Cowell et al., 1999; Beets et al., 1992), and on the Brazilian coast (Fitzgerald et al. 2007; Caldas et al., 2006). However, none of these studies precisely documents the transition from the transgressive phase to the regressive phase. Curray et al. (1969) and Roy et al. (1994) define the limit between the transgressive and regressive phases based on the composition of the sedimentary deposits of each phase. Caldas et al. (2006) and Fitzgerald et al. (2007), in turn, define this limit based on the preferential dip direction of the reflectors identified by the GPR technique, as also defined in the present study. At the moment of the transgression/regression inversion, the position of the coastline at the oceanic end of the emerged surface of the transgressive barrier represents the maximum landward position, i.e., the transgressive maximum position according to the definition by Curray (1964). The coastline at its maximum position is at the continental end of the RS between the Rf3 and Rf4 deposition (Fig. 4). The distance between this position (transgressive maximum) and the continent boundary within the washover fans (WF) indicates that the cross-

its landward migration when the backbarrier was already infilled. This aggradation phase in the lagoon represented the trigger for the inversion of the coastal barrier behavior (from transgressive to regressive), when inlets were restricted and closed, which caused the disappearance of Coscinodiscus marine diatoms in the IT-8 survey (Fig. 5). The deposition of the WF corresponds to beach and wind sediments of the coastal barrier that were dragged by storm waves to the backbarrier by subaquatic flow. This process originated the stratigraphic architecture indicative of coastline retreat due to the abrupt overlap of the adjacent lagoon/estuarine system (Leatherman and Williams, 1977). These deposits are considered diagnostic deposits of a transgressive coastal barrier (e.g., Pierce, 1969; Dillon, 1970), where sand, shell fragments and heavy minerals indicate changes in the hydraulic competence during storms (Kochel and Dolan, 1986). Because this deposition occurs episodically, it is always followed by the restoration of conditions previous to the deposition, which, in this case, was a lagoon margin environment (e.g., Morton, 1978; Ritchie and Penland, 1988; Leatherman and Williams, 1983; Davis et al., 1989; Donnelly et al., 2001). In the IT-3 survey, the geotechnical compaction profile of the WF alternates from very compacted to little compacted, indicating that the washover deposition alternated with the reestablishment of the sandy/muddy lagoon margin (Fig. 3). This alternation, however, does not have an impact on the diversity of diatoms and palynomorphs in the WF, which remains the same as that in the ELF, indicating that the backbarrier rapidly resumes its normal lagoon/estuarine deposition conditions after the storm event ceases. The main aspect in the contextualization of the WF is related to the macrofossils present in laminations of very fractured and abraded shells, with fragments of Cirripedes and regular echinoderms (sea urchins), the latter typical of rocky shores (Grosberg, 1981; Barnes, 1984). The taphonomy of these macrofossils indicates that they were removed from consolidated substrates, which were reworked in a beach environment, and only then transported to the backbarrier (lagoon/ estuarine) through the formation of washover fans. Because the WF results from beach erosion, the sand aggregates high concentrations of heavy minerals, making them easily traceable by the GPR method (e.g., Buynevich et al., 2004). In comparison with other radar facies, this facies is different because of the preferential dip direction of its reflectors, which is landward (Figs. 3 and 4). However, the geometry of these reflectors may vary from smooth (low-angle) to more abrupt (high-angle) geometries, emphasizing their position relative to the morphology of the barrier at the time of washover fan penetration (Figs. 3 and 4). In other words, high-angle reflectors are formed when the flow meets the lagoon margin, and the deposition occurs in the form of a typical washover fan, according to the definition by Schwartz (1975). Low-angle reflectors are formed in the rear of the foredunes, not reaching the lagoon complex. In Figs. 3 and 4, highangle reflectors are followed by low-angle reflectors, which implies the approach of the emergent portion of the barrier, occupying the lagoon margin in response to the landward migration of the barrier. The correlation between the WF in the lagoonal margin and the RS provides an approximation of the barrier geometry (horizontal dimension) in its transgressive configuration, i.e., the last erosive profile of the beach/foreshore associated with the transgressive phase, when the coastal barrier takes its current position isolating the lagoon complex at its rear (Fig. 6). The diagnostic criterion for recognizing the RS corresponds to the erosive truncation of the reflectors of the Rf4 radar facies. This truncation also indicates that the sedimentary deposits, required for the landward migration of the transgressive barrier, are obtained directly from the substrate of the barrier itself (WF) (e.g., Swift and Thorne, 1991). This morphostratigraphic pattern of the transgressive barrier indicates the erosional response, the retreat of the barrier (Sanders and Kumar, 1975), or even the retreat of the foreshore (Bruun, 1962; Swift, 1968), when the landward migration of the barrier truncates the pre-existing deposits by the action of the waves, creating the RS (Plint and Walker, 1987; Plint, 1988). 10

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

corresponds to the highest topographic boundary of the barrier in the study area. The beginning of the regressive phase (normal regression) was dated to 7.205 ± 55 years BP, corresponds to the foreshore sedimentation record (USF) and was deposited on the RS in the IT-5 survey (Fig. 6). This age agrees with that obtained by Dillenburg et al. (2006), confirming that the inversion of the transgressive/regressive depositional process occurred before the maximum sea level of the PMT. The progradational sequence of the beach/foreshore is limited at the base by an erosive discordance (RS) between the WF (washover fans) and the lower foreshore (LSF). In the particle size analysis, the LSF facies exhibits silt, with a low organic matter content and a high depth (−16 m), and it seems to reflect the dynamics of the internal continental shelf (e.g., Swift, 1975; Swift et al., 1985; Schieber, 1998). The dating of disarticulated M. patagonica valves resulted in an age of 5.125 ± 115 years BP for the LSF in the FS-17 survey. In this facies, both the shells and the sediments are iron oxide capped, indicating that the initial coverage of the RS may have aggregated siliciclastic and carbonate elements from a residual transgressive lag (e.g., Posamentier and Allen, 1999). The beginning of the progradational phase caused the deposition of Rf1 (transgressive dunes) immediately above the washover fans (Rf4) (Fig. 4, IT-3), indicating the first recorded development of the wind system. The origin of these dunes was probably associated with the decreased accommodation space generated by the closure of inlets and of the lagoon complex, as well as with lower rates of sea-level rise close to the Holocene eustatic maximum. This deficit in the accommodation space caused the dunes to migrate first on the surface of the inactive transgressive barrier and then on the regressive barrier as it advanced seaward. These transgressive dunefields did not move as the sea level continued to rise right before reaching the eustatic maximum, i.e., the normal regression phase of the barrier. This initial wind system exerted a great influence on the evolution of the barrier, increasing its height and protecting the backbarrier from washover (Donnelly, 2007; Williams and Flanagan, 2009; Priestas and Fagherazzi, 2010). The transgressive dunes that occur at the edge of the current barrier are probably a remnant of these first wind deposits anchored on the transgressive barrier (Fig. 6). This behavior of the wind system is similar to that currently operating in other sectors of the southern coast of Rio Grande do Sul, where transgressive dunes are connected with large transgressive barriers whose development is associated with a coastal sedimentary deficit and especially with the absence of washover fans (Dillenburg et al., 2004; Lima et al., 2013). The Rf2 radar facies is formed on the foreshore/backshore radar facies (Rf3) through the progradation of foredunes. This development coincides with the position of the highest PMT level (maximum elevation of Rf3 to +2 m above the RSL), indicating that the Rf2

sectional dimension of the transgressive barrier was 460 m at the moment before the transgressive/regressive transition (Fig. 6). This dimension of the transgressive barrier is similar to that of the existing transgressive barriers found in the Gulf of Mexico, which currently migrate landward as a result of the coalescence of washover fans (Morton and Sallenger, 2003; Rodriguez et al., 2004). The clearest sign of rising sea levels and therefore of the primordial force in the development of the transgressive barrier is the overlapping of the BPF by the ELF and of the latter by the WF. Together, these three facies define the transgressive sequence found in the present study. This stratigraphic pattern is commonly found in locations with transgressive coastal barriers (e.g., Fisher, 1961; Dillon, 1970; Demarest and Leatherman, 1985; Kochel and Dolan, 1986; Amorosi, 1995; Cattaneo and Steel, 2003; Buynevich et al., 2004; Lima et al., 2013). The spatial relationship between the base of the Holocene sediments (BPF) and the trajectory of the RS establishes the potential for the preservation of these transgressive deposits (e.g., Belknap and Kraft, 1981, 1985). The first recorded development of the progradational phase of the coastal barrier is seen within the reflectors of the Rf3, which, due to their high concentration of heavy minerals, represent the best-defined reflectors found in the present study. The continuity of the barrier development is monitored along almost all of the GPR profiling, except for the continental end of the RS (Fig. 4). These reflectors are located at a depth of −1 m with respect to the RSL, immediately above the RS. However, along the seaward GPR profiling (Figs. 3 and 4), they rise up to +2 m in the IT-5 survey, remaining in this position until they reach the current (modern) beach (Figs. 4 and 7). Thus, it is understood that in the initial development stage of the regressive barrier, the sea level was below the current level (-1 m). This topographic elevation of the FBF seaward indicates that the moment of the transgressive/regressive inversion was different from the eustatic maximum that occurred 6.000–5.000 years BP (Martin et al., 2003; Angulo et al., 2006). According to Dillenburg et al. (2006), the coastal barrier at Curumim, which is located 30 km to the south, was already undergoing progradation at 7.185 years BP. Thus, the point of inversion (transgression/ regression interface) was preserved to the west of the coastline (landward) and corresponded to the maximum sea level of the PMT (eustatic maximum), when the FBF facies reaches +2 m in the IT-5 and FS-15 surveys (Figs. 4 and 8). This result means that the initial progradation of the regressive barrier corresponded to a normal regression of the coastline and was later followed by a forced regression that persists until the present day. In summary, this transgressive/regressive inversion correlates with the transgressive maximum of the coastal barrier, whereas the maximum sea level of the PMT (eustatic maximum) is preserved in the regressive phase. This phase can be correlated to the point of inversion between normal and forced regression. This divergence between normal and forced regression corresponds to the location of the RS-389 highway (Fig. 1), which, on average, also

Fig. 7. Backshore and foreshore at Itapeva Beach. 11

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

Fig. 8. Stratigraphic cross-section of the present Holocene barrier/lagoon system at Rondinha Nova. (For the transect location, see Fig. 1).

indicating that the morphology of the adjacent barrier was segmented by connecting channels and that there was at least one important fluvial discharge in the backbarrier, which made this hydrodynamic condition (lagoon/estuarine) possible.

progradation is correlated with the beginning of decreasing sea levels (post-eustatic maximum); i.e., it develops in synchrony with the forced regression phase of the barrier. Thus, the development of transgressive dunes (Rf1) is associated with a normal regression phase, whereas the progradation of foredunes (Rf2) is related to the forced regression phase (Fig. 4). Therefore, foredune ridges cover the surface of the oceanic face of the barrier, whereas the internal compartment corresponds to the juxtaposition of relict transgressive dune ridges, interspersed with vegetated deflation plains (Hesp et al., 2007). According to Hesp et al. (2007), several phases of dune transgression eventually covered the original progradational surface of the barrier (Rf2). This covering by transgressive dunes (Rf1) occurred both in the normal regression phase (internal compartment of the barrier) and in the forced regression phase (oceanic compartment of the barrier). In the deflation plains between dune ridges, the occurrence of Chlorophytes, palynomorphs and freshwater diatoms indicates the stability of the water table in this compartment, modulating both the migration and the stabilization of these transgressive dunes (Figs. 4 and 5).

7.2. Middle holocene (maximum landward marine transgression) During the climax of the PMT, the coastal barrier systems present in this coastal segment reached the maximum rate of landward sediment transport, resulting in extensive deposition of washover fans (Fig. 9, Stage 3). These deposits advanced to the lagoon margin, indicating that the configuration of the coastal barrier at this time was essentially transgressive, with small height and width. The erosive truncation of the reflectors associated with the radar facies (Rf4) defines the geometry of the transgressive/regressive interface of the coastal barrier, showing the RS maximum incursion landward. The contact between the foreshore/backshore radar facies (Rf3) and the RS defines the location of the transgressive maximum or maximum advance of the coastline toward the continent. The last washover fan events were dated to 7.265 ± 45 years BP, indicating the end of the landward migration of the transgressive barrier. In spite of this, the establishment of this small barrier with a transgressive configuration also allowed the existence of numerous connection channels that reached their apogee approximately 7.560 ± 60 years BP, when the estuarine dynamics between lagoon and ocean were at their maximum. This date also marks the estuarine paleolevels (maximum levels) associated with the transgressive phase of the coastal barrier. The wind deposition associated with this normal regression phase established the formation of transgressive dunes (Rf1) that advanced on the barrier surface until stabilizing along the lagoon margin.

7. The evolution of Itapeva’s transgressive/regressive barrier system 7.1. Early holocene (early transgression) The pre-transgression continental environments originated in the North Coastal Plain of Rio Grande do Sul approximately 9.985 ± 205 years BP at the margins of a lagoon-barrier system (Fig. 9, Stage 1). These were exclusively freshwater paludal (basal peat) depositional environments and indicate the first record of the flooding of the previous topography. This flooding occurred as a result of higher water tables that followed rising sea levels at the beginning of the Holocene. The continuity of the marine transgression process in the Holocene discordantly covered pre-transgression (basal peat) continental environments with a lagoon/estuarine environment approximately 8.450 ± 110 years BP (Fig. 9, Stage 2). The association between palynomorphs and mollusks found in these early stages of the Holocene indicates the evolution of paludal to mixohaline conditions,

7.3. Late holocene The inversion of the retrogradational/progradational behavior of the coastal barrier in the Itapeva lagoon sector comprised the interval between the end of the transgressive phase, when the last washover fans occurred, dated to 7.265 ± 45 years BP, and the beginning of the regressive phase, when the foreshore began its progradation, dated to 12

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

Fig. 9. Five stages characterizing the evolutionary model of the Holocene transgressive/regressive barrier at Itapeva (schematic and not to scale).

7.205 ± 55 years BP (Fig. 9, Stage 4). This beginning of the progradational phase corresponded to a normal regression of the coastline, which was recorded by ascending topographic levels of the FBF and the Rf3 radar facies when they reach +2,1 m above the RSL in the IT-5 survey. Immediately after the establishment of the highest sea level of the PMT, the FBF and Rf3 (foreshore/backshore) began to respond to falling sea levels, which started the forced regression phase of the barrier (Fig. 9, Stage 5). The wind deposition in this phase corresponded to the progradation of foredunes (Rf2) and the aggradation of transgressive dunes (Rf1).

outcrop, subsurface, and seismic data. In: Berg, O.R., Woolverton, D.G. (Eds.), Seismic Stratigraphy II: An Integrated Approach to Hydrocarbon Exploration. Angulo, R.J., Lessa, G.C., Souza, M.C., 2006. A critical review of Mid- to Late Holocene sealevel fluctuations on the eastern Brazilian coastline. Quat. Sci. Rev. 25, 486–506. Anthony, D., Moller, I., 2002. The geological architecture and development of the Holmsland Barrier and Ringkobing Fjord area, Danish North Sea Coast. Geografisk Tidsskrift, Danish J. Geogr. 102, 27–36. Amorosi, A., 1995. Glaucony and sequence stratigraphy: a conceptual framework of distribution in siliciclastic sequences. J. Sediment. Res. 4, 419–425. Amorosi, A., Centineo, M.C., Colalongo, M.L., Fiorini, F., 2005. Millennial-scale depositional cycles from the Holocene of the Po Plain, Italy. Mar. Geology. 222–223, 7–18. Baeteman, C., Van Strijdonck, M., 1989. Radiocarbon dates on peat from the Holocene coastal deposits in West Belgium. In: Baeteman, C. (Ed.), Quaternary sea-level investigations from Belgium. Prof. Paper Belg. Geo. Dienst 241, pp. 59–91. Barboza, E.G., Dillenburg, S.R., Rosa, M.L.C.C., Tomazelli, L.J., Hesp, P.A., 2009. Groundpenetrating radar profiles of two Holocene regressive barriers in southern Brazil. J. Coast. Res. SI 56, 579–583. Barboza, E.G., Rosa, M.L.C.C., Dillenburg, S.R., Tomazelli, L.J., 2013. Preservation potential of foredunes in the stratigraphic record. J. Coast. Res. SI v.2, 1265–1270. Barnes, R.D., 1984. Zoologia dos Invertebrados, 4ª ed. Editora Livraria Rocca Ltda, São Paulo, pp. 1179. Barletta, R.C., Calliari, L.J., 2001. Determinação da Intensidade das Tempestades que atuam no litoral do Rio Grande do Sul, Brasil. Pesquisas em Geociências 28 (2), 117–124 Porto Alegre, Brasil. Beets, D.J., van der Valk, L., Stive, M.J.F., 1992. Holocene evolution of the coast of Holland. Mar. Geol. 103, 423–443. Beets, D.J., de Groot, T.A.M., Davies, H.A., 2003. Holocene tidal backbarrier development at decelerating sea-level rise: a 5 millennia record, exposed in the western Netherlands. Sed. Geol. 158, 117–144. Belknap, D.F., Kraft, J.C., 1981. Preservation potential of transgressive coastal lithosomes on the U.S. Atlantic shelf. Mar. Geology. 42, 429–442. Belknap, D.F., Kraft, J.C., 1985. Influence of antecedent geology on stratigraphic preservation potential and evolution of Delaware’s barrier systems. Mar. Geol. 63, 235–262. Bigarella, J.J., Hartkopf, C.C., Sobanski, A., Trevisan, N., 1955. Textura superficial dos grãos de areias e arenitos (Contribuição à metodologia). Curitiba. Arq. Biol. Tecn. X (11), 253–275. Boyd, R., Dalrymple, R., Zaitlin, B.A., 1992. Classification of clastic coastal depositional environments. Sed. Geol. 80, 139–150. Braga, M.F., Krusche, N., 2000. Padrão de ventos em Rio Grande, RS, no período de 1992 a 1995. Atlântica 22, 27–40. Bridge, J.S., Alexander, J., Collier, R.E.L., Gawthorpe, R.L., Jarvis, J., 1995. Ground-penetrating radar and coring used to study the large-scale structure of point-bar

8. Conclusion The results of the present study support the evolutionary considerations on the establishment of a basal transgressive (retrogradational) barrier before a regressive (progradational) barrier. The boundary between these depositional units is preserved by a wave ravinement surface defined by the erosive truncation of the transgressive barrier washover facies. The transition between these contrasting styles of coastal barriers occurred before the highest sea levels of the PMT were established, which created a normal regression phase during the progradation of the coastal barrier. At the end of the normal regression and post-eustatic maximum, the coastal barrier of Itapeva began its forced regression phase, which persists to the present day. In synthesis, occurs a diachronism condition between the maximum transgressive and the maximum eustatic sea-level. This behavior of early inversion of transgression to regression illustrates how a condition of high sedimentary deposition can overcome the creation of an accommodation space even under rising sea level conditions. References Abbott, W.O., 1985. The recognition and mapping of a basal transgressive sand from

13

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

Helland-Hansen, W., Martinsen, O.J., 1996. Shoreline trajectories and sequences: description of variable depositional-dip scenarios. J. Sediment. Res. B66, 670–688. Hesp, P., 1988. Morphology, dynamics and internal stratification of some established foredunes in southeast Australia. Sed. Geol. 55 (1-2), 17–41. https://linkinghub. elsevier.com/retrieve/pii/0037073888900887https://doi.org/10.1016/00370738(88)90088-7. Hesp, P.A., Dillenburg, S.R., Barbosa, E.G., Clerot, L.C.P., Tomazelli, L.J., Ayup-Zouain, R.N., 2007. Morphology of the Itapeva to Tramandaí transgressive dunefield barrier system and mid- to late Holocene sea level change. Earth Surf. Proc. Land. 32, 407–414. Hughen, K.A., et al., 2004. Marine04 marine radiocarbon age calibration, 0–26 Cal kyr BP. Radiocarbon 46, 1059–1086. Jol, H.M., Smith, D.G., 1991. Ground penetrating radar of northern lacustrine deltas. Can. J. Earth Sci. 28, 1939–1947. Jol, H.M., Smith, D.G., Meyers, R.A., 1996. Digital ground penetrating radar (GPR): An improved and very effective geophysical tool for studying modern coastal barriers (examples for the Atlantic, Gulf and Pacific coasts, U.S.A.). J. Coast. Res. 12 (4), 960–968. Kelley, J.T., Barber, D.C., Belknap, D.F., Fitzgerald, D.M., Van Heterenc, S., Dickson, S.M., 2005. Sand budgets at geological, historical and contemporary time scales for a developed beach system, Saco Bay, Maine, USA. Mar. Geol. 214, 117–142. Kochel, R.C., Dolan, R., 1986. The role of overwash on a mid-Atlantic coast barrier island. J. Geol. 94, 902–906. Kraft, J.C., 1971. Sedimentary facies patterns and geologic history of a Holocene marine transgression. AAPG 82, 2131–2158. Kraft, J.C., John, C.J., 1979. Lateral and vertical facies relations of transgressive barrier. AAPG 63, 2145–2163. Kraft, J.C., Chrzastowski, M.J., Belknap, D.F., Toscano, M.A., Fletcher III, C.H., 1987. The transgressive barrier-lagoon coast of Delaware: Morphostratigraphy, sedimentary sequences and responses to relative rise in sea level. In: Nummedal, D., Pilkey, O.H., Howard, J.D. (Eds.), The Society of Economic Paleontologists and Mineralogists Special Publication No. 41, pp. 129–143. Krumbein, W.C., 1941. Measurements and geologic significance of shape and roundness of sedimentary particles. J. Sed. Petrol. 11, 64–72. Leatherman, S.P., Williams, A.T., 1983. Vertical sedimentation units in barrier island washover fans. Earth Surf. Process. 8 (2), 141–150. Leatherman, S.P., 1987. Coastal geomorphic applications of ground penetrating radar. J. Coast. Res. 3 (3), 397–399. Leatherman, S.P., Williams, A.T., 1977. Lateral textural grading in overwash sediments. Earth Surf. Proc. Landforms 2, 333–341. Lessa, G., Masselink, G., 2006. Evidence of a mid-holocene sea level highstand from the sedimentary record of a macrotidal barrier and paleoestuary system in Northwestern Australia. J. Coastal Res. 22, 100–112. Lima, L.G., Medeanic, S., 2007. A variação morfológica dos fitólitos de opala em duas espécies de gramíneas na planície costeira do rio grande do sul e sua importância nas paleoreconstruções. XI Congresso da ABEQUA, 2007, Belém. Os estudos do Quaternário e a responsabilidade sócio ambiental. Lima, L.G., Medeanic, S., Dillenburg, S.R., 2007. Reconstrução Paleoambiental de uma Turfeira na Praia do Hermenegildo, RS: palinomorfos e diatomáceas. XI Congresso da ABEQUA, 2007, Belém. Os estudos do Quaternário e a responsabilidade sócio ambiental. Lima, L.G., Dillenburg, S.R., Medeanic, S., Barboza, E.G., Rosa, M.L.C.C., Tomazelli, L.J., Dehnhardt, B.A., Caron, F., 2013. Sea-level rise and sediment budget controlling the evolution of a transgressive barrier in southern Brazil. J. S. Am. Earth Sci. 42, 27–38. https://doi.org/10.1016/j.jsames.2012.07.002. Lima, S.F., Almeida, L.E.S.B., Toldo Jr., E.E., 2001. Estimate of longshore sediments transport from waves data to the Rio Grande do Sul coast. Pesquisas 28 (2), 99–107. Martin, L., Dominguez, J.M.L., Bittencourt, A.C.S.P., 2003. Fluctuating Holocene sea-levels is eastern and southeastern Brazil: evidence from a multiple fossil and geometric indicators. J. Coast. Res. 19, 101–124. Martinho, C.T., Hesp, P.A., Dillenburg, S.R., 2009. Morphological and temporal variations of transgressive dunefields of the northern and mid-littoral Rio Grande do Sul coast, Southern Brazil. Geomorphology(2009). https://doi.org/10.1016/j.geomorph 2009. 11.002. Medeanic, S., Corrêa, I.C.S., 2007. Silicoflagellate Dictyocha Ehrenberg from the Middle Holocene sediments in the coastal Plain of Rio Grande do Sul, Brazil. Revista Espanõla de Micropaleontologia 39 (3), 73–86. Meyers, R.A., Smith, D.G., Jol, H.M., 1994. Ground penetrating radar investigation of the internal structure of a Pacific coast barrier spit: Abstr. with Prog. Geol. Soc. Am. 26, 69. Milliman, J.D., Meade, R.H., 1983. World-wide delivery of river sediment to the oceans. J. Geol. 91, 1–21. Milliman, J.D., Syvitski, J.P.M., 1992. Geomorphic/Tectonic control of sediment discharge to the ocean: the importance of small mountainous rivers. J. Geol. 100, 525–544. Morton, R.A., 1978. Large-scale rhomboid bed forms and sedimentary structures associated with hurricane washover. Sedimentology 25, 183–204. Morton, R.A., Sallenger Jr., A.H., 2003. Morphological impacts of Extreme Storms on Sandy Beaches and Barriers. West Palm Beach, Florida. J. Coastal Res. 19 (3), 560–573. Munsell Color Company I, 2009. Geological Rock-color charts. Baltimore, Maryland. Murakoshi, N., Masuda, F., 1991. A depositional model for a flood tidal delta and washover sands in the late Pleistocene Paleo-Tokio Bay, Japan. In: Reinson, G.E., Zaitlin, B.A., Rahmani, R.A. (Eds.), Clastic Tidal Sedimentology. Can. Soc. Pet. Geol., Mem 16, pp. 219–226. Murray, A.B., Moore, L.J., 2018. Geometric constraints on long-term barrier migration:

deposits in three dimensions. Sedimentology 42, 839–852. Bristow, C.S., Chroston, P.N., Bailey, I.D., 2000. The structure and development of foredunes on a locally prograding coast: insights from ground-penetrating radar surveys, Norfolk. Sedimentology 47, 923–944. Bruun, P., 1962. Sea-level rise as a cause of shore erosion. Prcoeedings of the American Society of Civil Engineers. J. Waterw. Harbors Divis. 88, 117–130. Buynevich, I.V., Fitzgerald, D.M., Heteren, V., 2004. Sedimentary records of intense storms in Holocene barrier sequences. Maine, USA. Mar. Geol. 210, 135–148. Caldas, L.H.O., Oliveira Jr., J.G., Medeiros, W.E., Statteger, K., Vital, H., 2006. Geometry and evolution of Holocene transgressive and regressive barriers on the semi-arid coast of NE Brazil. Geo-Mar. Lett. 26, 249–263. Calliari, L.J., Tozzi, H.A.M., Klein, A.H.F., 1998. Beach morphology and coastline erosion associated with storm surges in Southern Brazil - Rio Grande to Chuí. Academia Brasileira de Ciências 231–247. Cattaneo, A., Steel, R.J., 2003. Transgressive deposits: a review of their variability. Earth Sci. Rev. 62, 187–228. Catuneanu, O., 2006. Principles of Sequence Stratigraphy. Elsevier, Amsterdam, pp. 375. Correa, I.C.S., Martins, L.R., Ketzer, J.M., Elias, A.R.D., 1995. A Plataforma Continental Sul e Sudeste Brasileira Durante O Holoceno. In: VII Congresso Latinoamericano de Ciencias del Mar, 1995, Mar del Plata-Argentina, vol. 1. Anais, Mar del PlataArgentina, pp. 56. Cowell, P.J., Roy, P.S., Jones, R.A., 1995. Simulation of large-scale coastal change using a morphological behaviour model: Amsterdam. Mar. Geol. 126, 45–61. Cowell, P.J., Roy, P.S., Cleveringa, J., de Boer, P.L., 1999. Simulating coastal systems tracts using the Shoreface-Translation Model. Int. Assoc. Sedimentol. Spe. Publ. Oxford, Blackwell Scientific Pub 62, 165–175. Curray, J.R., Emmel, F.J., Crampton, P.J.S., 1969. Holocene history of a strandplain, Lagoonal Coast, Nayariti, Mexico. In: Costouares, A.A., Phelger, V.B. (Eds.), Lagunas Costeras-Un simposio. Univ. National Autonoma do Mexico, pp. 64–100. Curray, J.R., 1964. Transgressions and regressions. In: Miller, R.L. (Ed.), Papers in Marine Geology. Macmillan, New York, pp. 175–203. Davis Jr., R.A., Andronaco, M., Gibeaut, J.C., 1989. Formation and development of a tidal inlet from a washover fan, west-central Florida coast, USA. Sedime. Geol. 65, 87–94. Field, M.E., Duane, D.B., 1974. Geomorphology and Sediments of the Inner Continental Shelf, Cape Canaveral, Florida, CERC No. 42. US Army Engineer Waterways Experiment Station. Demarest, J.M., Leatherman, S.P., 1985. Mainland influence on coastal transgression: Delmarva Peninsula. Mar. Geol. 63, 19–33. Dillenburg, S.R., Roy, P.S., Cowell, P.J., Tomazelli, L.J., 2000. Influence of antecedent topography on coastal evolution as tested by the shoreface translation-barrier model (STM). J. Coast. Res. 16, 71–81. Dillenburg, S.R., Tomazelli, J.L., Barbosa, E.G., 2004. Barrier evolution and placer formation at Bujuru southern Brazil. Mar. Geol. 203, 43–56. Dillenburg, S.R., Tomazelli, L.J., Hesp, P.A., Barbosa, E.G., Clerot, L.C.P., Silva, D.B., 2006. Stratigraphy and evolution of a prograded, transgressive dunefield barrier in southern Brazil. J. Coastal Res. SI 39 (1), 132–135. Dillenburg, S.R., Barbosa, E.G., Hesp, P.A., Rosa, M.L.C.C., 2011. Ground Penetrating Radar (GPR) and Standard Penetration Test (SPT) records of a regressive barrier in southern Brazil. J. Coastal Res. SI 64, 651–655. Dillenburg, S.R., Barbosa, E.G., Hesp, P.A., Rosa, M.L.C.C., Angulo, R.J., Souza, M.C., Giannini, P.C.F., Sawakuchi, A.O., 2014. Discussion: -Evidence for a transgressive barrier within a regressive strandplain system: implications for complex response to environmental change- by Hein, (2013), Sedimentology 60, 469-502. Sedimentology (Amsterdam. Print) 61, 2205–2212. Dillon, W.P., 1970. Submergence effects on a Rhode Island barrier lagoon and inferences on migration of barriers. J. Geol. 78, 94–106. DHN, 2011. Diretoria de Hidrografia e Navegação. https://www.marinha.mil.br/chm/ sites/www.marinha.mil.br.chm/files/dados_de_mare/imbituba_2011.pdf. Donnelly, J.P., Bryant, S.S., Butler, J., Dowling, J., Fan, L., Hausmann, N., Newby, P., Shuman, B., Stern, J., Westover, K., Webb, T., 2001. 700 yr sedimentary record of intense hurricane landfalls in southern New England. GSA Bull. 113 (6). Donnelly, C., 2007. Morphologic change by overwash – establishing and evaluating predictors. J. Coast. Res. SI 50, 520–526. Dominguez, J.M.L., Wanless H.R., 1991. Facies Architecture of a falling sea level strandplain, Doce river coast, Brazil. In: Swift, D.J.P., Oertel, G.F., Tillman, R.W., Thorne, J.A. (Org.). Shelf Sand and Sandstone Bodies - Geometry, Facies and Sequence Stratigraphy – International Association of Sedimentologists 14. Blackwell Scientific Publications, Oxford, pp. 259–281. Emery, D., Myers, K.J., 1996. Sequence Stratigraphy. Blackwell Science, London, pp. 297. Faegri, K., Iversen, J., 1989. Textbook of Pollen Analysis, fourth ed. John Wiley & Sons, New York. Fitzgerald, D.M., Cleary, W.J., Buynevich, I.V., Hein, C.J., Klein, A.H.F., Asp, N., Angulo, R., 2007. Strandplain evolution along the southern coast of Santa Catarina, Brazil. J. Coast. Res. SI 50, 152–156. Fisher, A.G., 1961. Stratigraphyc record of transgressive seas in the light of sedimentation on the Atlantic coast of New Jersey. AAPG 45, 1656–1666. Folk, R.L., Ward, W.C., 1957. Brazos River Bar: study and significance of grain size parameters. J. Sediment. Petrol. 27 (1), 03–26. Goldsmith, F.B., 1973. The vegetation of exposed sea cliffs at South Stack, Angsley. I. The multivariate approach. J. Ecol. 61, 787–818. Grosberg, R.K., 1981. Competitive hability influences habitat choice in marine invertebrates. Nature 290, 700–702. Hein, C., Fitzgeral, D., Cleary, W., Albernaz, M., Menezes, J.T., Klein, A.H.F., 2012. Evidence for a transgressive barrier within a regressive strandplain system: implications for complex coastal response to environmental change. Sedimentology 59. https://doi.org/10.1111/sed.12265.

14

Catena 185 (2020) 104263

L.G. Lima and C.K. Parise

Technical Memo 61. U.S. Army Corps of Engineers, pp. 69. Schwartz, R.K., 1982. Bedform and stratification characteristics of some modern smallscale washover sand bodies. Sedimentology 29, 835–849. Souza, M.C., 2005. Estratigrafia E Evolução Das Barreiras Holocênicas Paranaenses, Sul Do Brasil. Curso De Pós-Graduação Em Geologia Ambiental. Tese De Doutorado. Departamento De Geologia, Ufpr, Curitiba, pp. 96. Stolper, D., List, J.H., Thieler, E.R., 2005. Simulating the evolution of coastal morphology andstratigraphy with a new morphological-behavior model (GEOMBEST). Mar. Geol. 218, 17–36. Swift, D.J.P., 1968. Coastal erosion and transgressive stratigraphy. J. Geol. 76, 444–456. Swift, D.J.P., 1975. Barrier-island genesis: evidence from the central Atlantic shelf, eastern U.S.A. Sed. Geol. 14, 1–43. Swift, D.J.P., 1976. Continental shelf sedimentation. In: Stanley, D., Swift, D.J.P. (Eds.), Marine Sediment Transport and Environmental Management. John Wiley & Sons, New York, pp. 311–350. Swift, D.J.P., Thorne, J.A., 1991. Sedimentation on Continental Margins, I - a general model for shelf sedimentation. Spec. Publ. Int. Assoc. Sedimentol. 14, 3–31. Swift, D.J.P., Niederoda, A.W., Vincent, C.E., Hopkins, T.S., 1985. Barrier island evolution, middle Atlantic shelf, USA, Part 1: shoreface dynamics. Mar. Geol. 63, 331–361. Syvitski, J.P.M., Peckham, S.D., Hilberman, R., Mulder, T., 2003. Predicting the terrestrial flux of sediment to the global ocean: a planetary perspective. Sed. Geol. 162, 5–24. Talma, A.S., Voge, L.J.C., 1993. A simplified approach to the calibration of Radiocarbon dates. Radiocarbon 35 (2), 317–322. Thom, B.G., Roy, P.S., 1983. Sea-level change in New South Wales over the past 15,000 years. In: Hopley, D. (Ed.), Australian Sea Levels in the Last 15,000 Years: A Review, James Cook University of North Queensland, Monograph Series, Occasional Paper 3. Geography Department, pp. 64–84. Thom, B.G., 1984. Transgressive and regressive stratigraphies of coastal sand barrier in southeast Australia. Mar. Geol. 56, 137–158. Tomazelli, L.J., Villwock, J.A., 1992. Considerações sobre o ambiente praial e a deriva litorânea de sedimentos ao longo do litoral norte do Rio Grande do Sul, Brasil. Instituto de Geociências, UFRGS. Porto Alegre. Pesquisas 19, 3–12. Tomazelli, L.J., Villwock, J.A., Dillenburg, S.R., Bachi, F.A., Dehnardt, B.A., 1998. Significance of present-day coastal erosion and marine transgression, Rio Grande do Sul, Southern Brazil. Anais da Academia Brasileira de Ciencias 70 (2), 221–229. Tomazelli, L.J., Villwock, J.A., 1996. Quaternary Geological Evolution of Rio Grande do Sul Coastal Plain, Southern Brazil. An. Acad. Bras. Ciencias. 68, 373–382. Tozzi, H.A.M., Calliari, L.J., 2000. Morfodinâmica da praia do Cassino. Pesquisas 27, 29–42. Vail, P.R., Mitchum, J.R., Todd, R.G., Widmier, J.M., Thompson III, S., Sangree, J.B., Bubb, J.N., Hatlelid, W.G., 1977. Seismic stratigraphy and global changes of sealevel. In: Payton, C.E. (Ed.), Seismic Stratigraphy—Applications to Hydrocarbon Exploration. American Association of Petroleum Geologists Memoir, pp. 49–212. van Overmeeren, R.A., 1998. Radar facies of unconsolidated sediments in The Netherlands: a radar stratigraphy interpretation method for hydrogeology. J. Appl. Geophy. 40, 1–18. van Wagoner, J.C., Mitchum, R.M., Campion, K.M., Rahmanian, V.D., 1991. Siliciclastic sequence stratigraphy in well logs, cores and outcrops: cencepts for high-resolution correlation of time and facies. Am. Assoc. Petrol. Geol. Meth. Explor. Ser. 7, 55. Villwock, J.A., Tomazelli, L.J., Loss, E.L., Dehnhardt, E.A., Bachi, F.A., Dehnhardt, B.A., 1986. Geology of the Rio Grande do Sul Coastal Province. In: In: Rabassa, J. (Ed.), Quaternary of South America and Antartic Peninsula, vol. 4. A.A. Balkema, Rotterdam, pp. 79–97. Wetzel, R.G., 1975. W.B. Sauders Company, Philadelphia, London, and Toronto. Limnology Xii, 743. Williams, H.F.L., Flanagan, W.M., 2009. Contribution of Hurricane Rita storm surge deposition to long-term sedimentation in Louisiana coastal woodlands and marshes. J. Coast. Res., Special Issue 56, 1671–1675.

from simple to surprising. In: Moore, L.J., Murray, A.B. (Eds.), Barrier Dynamics and Response to Changing Climate. Springer, New York. Neal, A., Roberts, C.L., 2000. Applications of ground-penetrating radar (GPR) to sedimentological, geomorphological and geoarchaeological studies in coastal environments. Geological Society London, Special Publications 175, 139–171. Neal, A., Richards, J., Pye, K., 2003. Sedimentology of coarse clastic beach ridge deposits, Essex, Southeast England. Sediment. Geol. 162, 167–198. Neal, A., 2004. Ground-penetrating radar and its use in sedimentology: principles, problems and progress. Earth-Sci. Rev. 66, 261–330. Nimer, E., 1990. Clima. In: IBGE. Geografia do Brasil: região Sul, vol. 2. Instituto Brasileiro de Geografia e Estatística, Rio de Janeiro, pp. 113–150. Parise, C.K., Calliari, L.J., Krusche, N., 2009. Extreme storm surges in the south of Brazil: atmospheric conditions and shore erosion. Braz. J. Oceanogr. 57 (3), 175–188. Pierce, J.W., 1969. Sediment budget along a barrier island chain. Sed. Geol. 3, 5–16. Plint, A.G., Walker, R.G., 1987. Morphology and origin of an erosional surface cut into the Bad Heart Formation during major sea-level change, Santonian of west-central Alberta, Canada. J. Sediment. Petrol. 57, 639–650. Plint, A.G., 1988. Sharp-based shoreface sequences and ‘‘offshore bars’’ in the Cardium formation of Alberta: their relationship to relative changes in sea level. In: Wilgus, C.K., Hastings, B.S., Kendall, C.G.Si.C., Posamentier, H.W., Ross, C.A., Van Wagoner, J.C. (Eds.), Sea-Level Changes—An Integrated ApproachSEPM, Special Publication 42, pp. 357–370. Posamentier, H.W., Allen, G.P., 1999. Silisiclastic Sequence Stratigraphy Concept and Aplication. Society for Sedimentary Geology, Tulsa. Priestas, A.M., Fagherazzi, S., 2010. Morphological Barrier Island Changes and Recovery of Dunes after Hurricane Dennis, St. George Island, Florida. Geomorphology 114, 614–626. Randall, W.P., 1989. Decelerating Holocene sea-level rise and its influence on Southwest Florida coastal evolution: a transgressive/regressive stratigraphy. J. Sediment. Petrol. 59 (6), 960–972. Reimer, P.J., et al., 2004. Radiocarbon 46, 1029–1058. Ritchie, W., Penland, S., 1988. Rapid dune changes associated with overwash processes on the deltaic coast of South Louisiana. Mar. Geol. 81, 97–122. Ritchie, W., Penland, S., 1990. Aeolian sand bodies of the south Louisiana coast. In: Nordstrom, K.F., Psuty, N.P., Carter, R.W.G. (Eds.), Coastal Dunes Form and Process. Wiley, London, pp. 105–127. Rittenhouse, G., 1943. A visual method of estimating two dimensional sphericity. J. Sed. Petrol. 13 (2), 79–81. Rodriguez, A.B., Anderson, J.B., Siringan, F.P., Taviani, M., 2004. Holocene evolution of the east Texas coast and inner continental shelf: along-strike variability in coastal retreat rates. J. Sediment. Res. 74 (3), 405–421. Roy, P.S., Cowell, P.J., Ferland, M.A., Thom, B.G., 1994. Wave dominated coasts. In: Carter, R.W.G., Woodroffe, C.D. (Eds.), Coastal Evolution, Late Quaternary Shoreline Morphodynamics. Cambridge University Press, Cambridge, pp. 121–186. Roy, P.S., 1994. Holocene estuary evolution—stratigraphic studies from southeastern Australia. In: In: Dalrymple, R.W., Boyd, R., Zaitlin, B.A. (Eds.), Incised-Valley Systems: Origin and Sedimentary Sequences. Special Publication, vol. 51. Society for Sedimentary Petrology, pp. 241–264. Samuelsberg, T.J., Pickard, N.A.H., 1999. Upper Carboniferous to Lower Permian transgressive–regressive sequences of central Spitsbergen Arctic Norway. Geol. J. 34, 393–411. Sanders, J.E., Kumar, N., 1975. Evidence of shoreface retreat and in-place ‘‘drowning’’ during Holocene submergence of barriers, shelf off Fire Island, New York. Geol. Soc. Am. Bull. 86, 65–76. Schieber, J., 1998. Deposition of mudstones and shales. Overview, problems and challenges. In: In: Schieber, J., Zimmerle, W., Sethi, P.S. (Eds.), Clay Minerals Vol I. Basin Studies, Sedimentology and Paleontology, vol. 35; no. 2. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, pp. 456–457. Schwartz, R.K., 1975. Nature and Genesis of Some Storm Washover Deposits. CERC

15