Geochemical signatures of bedded cherts of the upper La Luna Formation in Táchira State, western Venezuela: Assessing material provenance and paleodepositional setting

    Geochemical signatures of bedded cherts of the upper La Luna Formation in T´achira State, western Venezuela: Assessing material provenance and paleodepositional setting G. Garb´an, M. Mart´ınez, G. M´arquez, O. Rey, M. Escobar, N. Esquinas PII: DOI: Reference:

S0037-0738(16)30108-7 doi:10.1016/j.sedgeo.2016.11.001 SEDGEO 5128

To appear in:

Sedimentary Geology

Received date: Revised date: Accepted date:

6 June 2016 31 October 2016 4 November 2016

Please cite this article as: Garb´an, G., Mart´ınez, M., M´ arquez, G., Rey, O., Escobar, M., Esquinas, N., Geochemical signatures of bedded cherts of the upper La Luna Formation in T´ achira State, western Venezuela: Assessing material provenance and paleodepositional setting, Sedimentary Geology (2016), doi:10.1016/j.sedgeo.2016.11.001

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ACCEPTED MANUSCRIPT Geochemical signatures of bedded cherts of the upper La Luna Formation in Táchira State, western Venezuela: assessing material

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provenance and paleodepositional setting

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G. GARBÁNa, M. MARTÍNEZa,b, G. MÁRQUEZc,*, O. REYd, M. ESCOBARe and N. ESQUINASf a

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Instituto de Ciencias de la Tierra, Universidad Central de Venezuela, Caracas, 3895, 1010-A, Venezuela Facultad de Ingeniería, Universidad Estatal Península de Santa Elena, Vía La Libertad-Santa Elena s/n, 7047 c Departamento de Ingeniería Minera, Mecánica y Energética, Universidad de Huelva, Huelva, 21819 Huelva, Spain d Escuela de Geología, Minas y Geofísica, Universidad Central de Venezuela, Caracas, 3895, 1010-A, Venezuela e Facultad de Ingeniería, University of Zulia &CARBOZULIA, Av. 2, No. 55-185, Maracaibo, 4002-A, Venezuela f Departamento de Explotación y Prospección de Minas, Universidad de Oviedo, C/G. Gutiérrez, 33600 Mieres, Spain

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b

Abstract: Here we undertook an inorganic geochemical study of Cenomanian-Campanian bedded cherts (the Táchira

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Ftanita Member of the La Luna Formation) in the western region of the Táchira State, Venezuela. The aim of this study was to determine the paleo-oceanographic and paleo-environmental conditions that governed the deposition of chert beds and put forward a sedimentation model for the Táchira Ftanita Member in the study area. Seventy-two chert

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samples were collected and trace/rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Rb, Cs,

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Th, U, Y, Co, and Sc) and major/trace elements (SiO2, TiO2, Al2O3, Fe2O3, MgO, CaO, Na2O, K2O, P2O5, Mn, Ba, Sr, Cr, Ni, and V) were determined by ICP-MS and ICP-OES, respectively. On the basis of the stratigraphic abundance and distribution of relatively immobile elements, as well as the distribution of rare earth elements, we established that the

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detrital sediments associated with the sequences studied have matching characteristics with distinct continental materials, with an intermediate composition, thus pointing to the Guayana Massif as the main source of sediments. In addition, we also determined the influence of hydrothermal input on the chemical composition of some cherts from La Molina Mine. On the basis of geochemistry, we found a biological influence regarding the uptake of dissolved silica for

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forming chert beds. The application of parameters for relatively immobile elements allowed us to establish a still proximal continental-margin (hemipelagic) for most samples from the Zorca River and a continental-margin for almost all the cherts from the Delicias-Villa Páez section and the remaining samples from La Molina Mine. Finally, we propose that the rhythmicity that accompanies the sequence of bedded cherts is related to changes in the intensity of upwelling patterns of water and/or to variability in the supply of silica dissolved in the Táchira sub-basin. Keywords: bedded chert, Táchira Ftanita Member, depositional setting, provenance, modified Murray diagram.

1. Introduction The geochemical study of bedded chert sequences has wide application in the context of determining their genesis (Chen et al., 2006), depositional environments (Murray, 1994; Halamić et al., 2005; Yu et al., 2009; Udchachon et al., 2011; Kemkin and Kemkina, 2015), paleogeographic *

[email protected]

Tfn./Fax: +34959217325

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ACCEPTED MANUSCRIPT variations and global paleoenvironmental changes (Kato et al., 2002), paleo-upwelling zones and primary productivity areas (Ragueneau et al., 2000; Muttoni and Kent, 2007), and sediment

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provenance indicators (Owen et al., 1999; Eker et al., 2012). Dark gray to black lithofacies is a

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special group of bedded cherts which, depending on their location, tectonics and age, have been

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given a series of names (e.g., phthanites). These facies can be particularly rich in organic matter content, and the conditions under which they were deposited are associated with oceanic anoxic events, particularly those that occurred during the Late Cretaceous Period in the South American

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continent (Villamil, 1999) and elsewhere (Scopelliti et al., 2004; Takashima et al., 2004). In this regard, certain paleo-oceanographic conditions allowed the sedimentation of black bedded chert

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sequences in the west (La Luna Formation) and the east (San Antonio Formation) of Venezuela

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(Villamil et al. 1999).

One of the most conspicuous expressions of the black chert beds deposited in the northern part of

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South America is found in the state of Táchira, near the border between Venezuela and Colombia (Maceralli and DeVries, 1987). This regional extension, which has been referred to in the literature

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as Táchira Chert Member, is one of the most emblematic features of the La Luna Formation deposited during the Santonian-Campanian along the Depression of Táchira (see Fig. 1a showing worldwide palaeogeographic map of the Cretaceous Period), the latter being a sub-basin located between the so-called neritic and pelagic sedimentary provinces in northwestern South America (Macellari and DeVries, 1987). Apart from some studies of a local nature (Camero, 2002; Garbán and Martínez, 2007), no systematic geochemical data have been reported for Late Cretaceous cherts from the Táchira Ftanita Member. Here we present data on rare earth elements (REEs) and major/trace elements for black chert samples from the Zorca River (holostratotype), La Molina Mine, and Delicias-Villa Páez sections of the aforementioned Member in western Venezuela (Fig. 1b). In addition, we discuss the origin of the silica and detrital material that they contain, as well as their depositional settings. A regional lithostratigraphic correlation of these three outcrop sections 2

ACCEPTED MANUSCRIPT was carried out by Garbán (2010). In the present study, the geochemical features of the La Molina Mine cherts are compared with those of the Zorca River and Delicias-Villa Páez sections, in order

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to provide information on the paleo-oceanographic conditions that governed the deposition of the

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black chert beds in the region under study.

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Figure 1

Although the chemistry of these sedimentary rocks is controlled by several factors, such as the composition of the detrital material (elements such as Si, Al, Ti, Ca, Mg, K, Na or Th), the biogenic

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contribution and the components derived from hydrothermal input (Jones and Murchey, 1986), the most important contributor is the diagenetic fractionation caused by the high proportion of SiO2

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(c.a. 95 wt. %) and the subsequent dilution effect on the other elements (Murray, 1994). In this regard, the distribution of immobile trace elements, such as Zr, Hf, Ta and Nb, and especially rare

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earth elements (REEs), has been widely used as an indicator of depositional environments in which bedded chert sequences originated (Shimizu and Masuda, 1977; Murray, 1994; Yu et al., 2009;

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among others).

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2. Geological background

The Lake Maracaibo Basin is located towards the southern end of the Caribbean Sea in western Venezuela, near the border with Colombia. This basin comprises a thick sedimentary cover divided into various sequences on the basis of the following tectonic events: a Jurassic rift succession; an Early-Late Cretaceous passive margin sequence; the transition to a compressive regime in the Late Cretaceous-Early Paleocene deposits when the Pacific volcanic arc collision emplaced the “Lara Nappes” to the northern edge of the aforementioned basin; the formation of a Late PaleoceneMiddle Eocene foreland basin in front of the volcanic arc; and a Late Eocene-Pleistocene sequence related to the collision of the Panama arc with the South American plate (e.g., Mann et al., 2006; Escalona and Mann, 2011).

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ACCEPTED MANUSCRIPT According to González de Juana et al. (1980), the sedimentary column of the Depression of Táchira in the southwest of Lake Maracaibo Basin overlies the igneous-metamorphic basement and begins

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with the red-bed sediments of the Jurassic La Quinta Formation (Fig. 2). Later, during thermal

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subsidence of the passive margin of South America into the Early Cretaceous, the Río Negro, Apón,

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Capacho, and Aguardiente formations were deposited. The La Luna Formation was also deposited during a series of four marine transgressions of late Cretaceous age and related oceanic anoxic events (Parnaud et al., 1995; Pérez-Infante et al., 1996; Villamil, 1999; among others). The latter

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unit presents sedimentary structures such as parallel laminations to millimeter scale that suggest a lack of bioturbation (Macsotay et al. 2003). These transgressive episodes were followed by the

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beginning of a regressive succession with the shallow marine deposition of the Colon Formation as a result of oblique collision between the westward-migrating Caribbean island arc and the passive

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margin of South America (Lugo and Mann, 1995; Erlich et al., 1999). During the later Cretaceous period, the Mito Juan unit began to be deposited in deltaic settings (Sutton, 1946).

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Figure 2

The Late Cretaceous bedded chert sequence found outcropping in Táchira State has been

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recognized as a formal member of the La Luna Formation, thereby allowing its subsequent classification as Táchira Ftanita Member (Trump and Salvador, 1964). The Coniacian-Santonian Táchira Chert Member (80-100 m thick) is composed of rhythmically bedded (5 to 20 cm) and thinly laminate cherts, with minor interbedded black carbonatic shales, marls, and dark gray limestones (Renz, 1959). A detailed study (Marcucci, 1976) of the lithology of the Táchira Ftanita Member allowed the identification of three types of chert associated with this unit – these defined on the basis of varying proportions of clay minerals or calcite within a matrix of microgranular quartz. These cherts are characterized by two matrices, one formed by fine-grained cryptocrystalline quartz and another by megagranular quartz that is lighter in color (Garbán, 2010).

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ACCEPTED MANUSCRIPT It has been suggested that the deposition of the Táchira Ftanita Member took place between the neritic setting and the deep pelagic environment, and that it represents a transitional state between

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strongly anoxic depositional conditions and more oxidant conditions (Marcucci, 1976). The

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presence of poorly preserved radiolarian remains in black bedded cherts supports the hypothesis of

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a volumetrically significant contribution of biogenic silica (González de Juana et al., 1980). García Jarpa et al. (1980) postulated that the chert samples from the Táchira Ftanita Member have a diagenetic origin. On the other hand, several authors (e.g., Maceralli, 1988; Erlich et al., 2000)

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proposed that the sequence of chert beds in the La Luna Formation was evidence of strong

3. Samples and experimental methods

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3.1 Sampling

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upwelling currents, which promoted a high rate of productivity for silica-secreting microorganisms.

A set of seventy-two chert samples were collected from the Táchira Ftanita Member of the La Luna

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Formation near the Colombian-Venezuelan border. In detail, thirty-two samples (named as TZF) were collected from the Zorca River, about 10 km north of the San Cristobal city (coordinates equal

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to 7º49'12"N, 72º16'12"W); twenty-one samples (named as TLM) were also collected from the La Molina Mine section (7º55'30"N, 72º13'48"W), 27 km north of the city of San Cristobal, and nineteen samples (named as TVP) from a section (7º32'42"N, 72º27'00"W) along a site cut on the road between the villages of Delicias and Villa Páez, 60 km south-west of San Cristobal. The locations of the three sampling sites are shown in Figure 1. The location of each sample in the respective stratigraphic column is shown in Figure 3. Figure 3 3.2 Analytical procedures An aliquot (about 50 g) of each chert sample was crushed and pulverized using a Shatterbox 5540 with a tungsten carbide grinding container. Later, a portion (~0.1 g) of each freeze-dried and powdered sample was dissolved by microwave digestion and a series of dissolution and evaporation 5

ACCEPTED MANUSCRIPT steps involving HNO3, HF, HCl, and H2O2, following a procedure similar to that reported by Murray and Leinen (1996). Then, concentrated H3BO3 (5% wt/v) was added to remove excess HF.

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Once the samples were completely digested, solutions were diluted 100- and 1000-fold for trace and

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major/minor element analyses, respectively. Geochemical analyses of 9 major/minor elements

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(SiO2, TiO2, Al2O3, Fe2O3, MgO, CaO, Na2O, K2O, and P2O5), expressed as % w/w oxides, as well as Mn and 5 trace elements (Cr, Ni, V, Ba, and Sr), expressed as mg/kg, were determined by inductively-coupled plasma optical emission spectroscopy (ICP-OES) using a Jobin-YvonUltima-C

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spectrometer. Also, 7 trace elements (Rb, Cs, Th, U, Y, Co, and Sc) and REEs (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), expressed as mg/kg, were determined by inductively-

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coupled plasma mass spectrometry (ICP-MS) by means of a ThermoFinnigan VG Elemental Plasma QuadExCell. We have also considered previous sulfur content (S) and total organic carbon (TOC)

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data (Garbán, 2010) on the thirty-two chert samples from the Zorca River section (Appendix A-1).

4. Results

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Accuracy and precision values are shown in Appendices A-1, A-2, and A-3.

4.1.1. SiO2

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4.1. Major/minor elements

Appendix A-1 shows the content of major and minor element oxides in the samples on a dry, ash basis. Also, stratigraphic profiles of some proxies such as SiO2, Al2O3, CaO and Fe2O3 are shown in Appendix B. As expected, the samples were SiO2 enriched (generally about 90%), while being depleted in some other elements. The samples from the Zorca River and La Molina Mine were split into two clearly distinguishable groups: one corresponding to pure cherts (> 80% SiO2), which showed SiO2 concentrations averaging 88.49 %, and another group (13 samples) consisting of calcareous chert with an average SiO2 content of 74.10 %. However, the samples from the DeliciasVilla Páez section formed a homogeneous group with an average SiO2 concentration of 92.17%. This value would place this group in the so-called pure cherts identified in the previous two 6

ACCEPTED MANUSCRIPT sections. For the three sections studied, the SiO2 stratigraphic variations were not notable. SiO2 content showed a negative Spearman rank correlation (Rs) with the other major elements in the 3

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sections studied (see Appendix C-1). This negative correlation is attributed to the so-called SiO2

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dilution effect. We applied the Spearman´s coefficients to element abundance data and avoided

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making assumptions about frequency distributions (Rollison, 2014). 4.1.2. Al2O3, K2O, TiO2, and Fe2O3

There was a strong positive correlation (Rs) between the contents of Al2O3, K2O, TiO2, and Fe2O3 in

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all the sections studied (see Appendix C-1), thereby indicating that they are controlled by common chemical processes. Generally, these elements are associated with detrital aluminosilicate phases,

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which can include phases of resistates and authigenic minerals (Garbán, 2010). Samples from the Zorca River and La Molina Mine showed an average Al2O3 concentration of 1.37 and 0.56%,

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respectively, for pure cherts, while the group of calcareous chert averaged 1.93 and 1.34%. The samples from the Delicias-Villa Páez section showed an average Al2O3 content of 0.54%. Contents

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of K2O and TiO2 in samples from the Zorca River averaged 0.19 and 0.04 %, respectively, for pure cherts, and 0.28 and 0.05% for calcareous cherts. Regarding the La Molina Mine section, the

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average contents of K2O and TiO2 were 0.08% and 0.028% for pure cherts, and 0.14% and 0.04%, respectively, for calcareous cherts. Also, the K2O and TiO2 concentrations in samples from the Delicias-Villa Páez section averaged 0.06% and 0.018%. Finally, stratigraphic variations in the concentrations of these four major elements were minimal for the sections studied (Appendix A-1). 4.1.3. CaO The samples from the Zorca River and La Molina Mine showed an average CaO concentration of 5.12% and 3.61%, respectively, for pure chert, and an average of 13.65% and 13.86% for calcareous chert. Samples from the Delicias-Villa Páez section averaged a CaO content of 4.37%. On the other hand, positive Spearman rank correlations shown by CaO were not identical for the three sections studied (see Appendix C-1). For Zorca River cherts, CaO correlated positively with MgO and P2O5; in the La Molina Mine section, there was also a moderate positive correlation (Rs) 7

ACCEPTED MANUSCRIPT between CaO and Mn. In contrast, in the Delicias-Villa Páez section there was no correlation between CaO and MgO and CaO correlated positively with Na2O.

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4.1.4. P2O5

The P2O5 content in all chert samples from the three sections was below 1.00%. All the samples

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showed a low variability in P2O5 concentration, thereby suggesting that the phosphorus content was relatively constant. In the Zorca River, pure cherts showed an average concentration of 0.28%, and

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calcareous cherts of 0.71%. In the La Molina Mine, pure and calcareous cherts showed an average concentration of 0.13% and 0.22 %, respectively. Regarding the Delicias-Villa Páez section, the

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average P2O5 concentration was 0.16%.

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4.2. Rare earth elements

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Appendix A-2 shows the concentrations of 14 REEs of the lanthanide series (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb y Lu) for all the samples. Stratigraphic profiles of ΣREE are shown

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in Appendix B. Post-Archean Average Australian Shale (PAAS)- normalized concentrations of REEs are shown in Supplementary material I.

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4.2.1. REE terminology

The subscript “sn” indicates PAAS-normalized abundances. REE normalization to PAAS values is helpful becuase REE profiles for average shale and the average upper continental crust (McLennan, 1989) exhibit a similar behavior, among other aspects. In addition, the Ce and Eu anomalies are defined by the ratios Cesn/Ce* and Eusn/Eu*, with Ce* and Eu* being obtained by linear interpolation between Lasn and Prsn and between Smsn and Gasn, respectively (Murray et al., 1992a and b). Samples with Cesn/Ce* (or Eusn/Eu*) < 1 (> 1) are considered to have a “negative (positive) Ce (or Eu) anomaly”. Finally, variations in behavior across the REE series are denoted by the ratio of heavy REE (HREE) to light REE (LREE), here defined as Lasn/Ybsnor Lasn/Tmsn (Amstrong et

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ACCEPTED MANUSCRIPT al., 1999). Samples with Lasn/Ybsn< 1 (> 1) show HREE enrichment (depletion) when compared to LREE. Similarly, the subscript “n” indicates chondrite- or C1-normalized abundances. 4.2.2. ΣREE, Cesn/Ce*, Eusn/Eu* and Lasn/Ybsn

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Pure chert samples from the Zorca River and La Molina Mine showed average ΣREE values of

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19.42 (±20.71) and 17.69 ppm (±14.30) mg/Kg, respectively; while calcareous chert samples averaged 56.88 (±26.12) and 31.18 (±9.36) mg/Kg. For Delicias-Villa Páez cherts, ΣREE averaged 18.99 (± 6.70) mg/Kg. The stratigraphic variation in ΣREE did not show a definite trend in the

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sections studied. When comparing average ΣREE values for the Zorca River, La Molina Mine, and Delicias Villa-Páez sections (39.9, 43.9 and 35.9 mg/Kg) with those reported in the literature for

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PAAS (183 mg/Kg; Taylor and McLennan, 1985) or North American Shale Composite (173 mg/Kg; Gromet et al., 1984), significant differences were observed. Most pure chert samples

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(except TZF-160 and TZF-280) from the holostratotype showed a common REE pattern (Fig. 4a), showing moderate negative or positive Ce anomalies (Cesn/Ce* in the 0.70-1.56 range) and negative

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or slightly positive Eu anomalies (Eusn/Eu* between 0.60 and 1.05). It is also noteworthy that both Tb and Yb contents were close to the detection limit. However, a slight or no HREE enrichment

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was observed when compared to LREE (Lasn/Tmsnin the 0.35-1.01, averaging 0.65±0.18). In turn, TZF-160 and TZF-280 exhibited Lasn/Tmsn values of 1.87 and 1.59, respectively, denoting LREE enrichment with respect to HREE (see Fig. 4b). Moreover, the calcareous chert samples from the Zorca River (TZF-170, TZF-200, TZF-205, TZF-225, TZF-235, TZF-255, TZF-300 and TZF-400) showed almost identical profiles (see Fig. 4c), with negative Ce anomalies (Cesn/Ce* in the 0.710.83 range) and either small negative or no Eu anomalies (Eusn/Eu* between 0.89 and 1.00). Also, Lasn/Ybsn values slightly higher than unity (averaging 1.28±0.30) implied no considerable LREE enrichment. Figure 4 In contrast, pure chert samples from the La Molina Mine section generally displayed small negative or slightly positive Ce anomalies (Cesn/Ce* averages 1.10±0.18) and clear positive Eu anomalies 9

ACCEPTED MANUSCRIPT (Eusn/Eu* averaging 2.33±0.87), except TLM-145. Moreover, Lasn/Ybsn values were generally greater than unity (see Fig. 5a). Calcareous cherts from the La Molina Mine section (TLM-033,

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TLM-122, TLM-125, TLM-140, and TLM-200) showed a common REE pattern similar to that

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observed for the holostratotype (Fig. 5b), but with small or negligible Ce anomalies (Cesn/Ce*

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averaging 0.96±0.26) and positive Eu anomalies (Eusn/Eu* averaging 2.40±0.71), except TLM-033. Finally, samples from the Delicias-Villa Páez section exhibited PAAS-normalized REE patterns (see Fig. 5c) characterized by slightly or negligibly positive Ce anomalies (Cesn/Ce* in the range

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1.06-1.55; 1.28±0.14), negative Eu anomalies (Eusn/Eu* ranging from 0.11 to 0.97; 0.49±0.29), and a negligible LREE enrichment compared to HREE (Lasn/Ybsn data ranging between 0.71 and 1.30).

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Figure 5

4.3. Trace elements

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Appendix A-3 shows the concentrations of Mn and 12 trace elements in the samples. For samples from the Zorca River section, some elements, such as Sc, were present below the detection limit for

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at least 95% of the samples. However, for the sections of La Molina Mine and Delicias-Villa Páez,

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these elements were detected in most samples, in contrast to other elements such as Ag, Ga, and Tl.

Geochemical concentrations of redox-sensitive trace elements, normalized to average shale values reported by Wedepohl (1991), were compared using Al as detritus index and enrichment factors (EF: EFX equals to X/Alsample/X/Alaverage shale). If EFX is higher and lower than unity, then element X is enriched and depleted relative to average shales, respectively (Tribovillard et al., 2006). Figure 6 groups these elements for each section studied on the basis of the EF values obtained (very enriched when EF exceeds 10; enriched when EF is in the 3-10 range; and depleted when EF is below 1). Figure 6 Enrichment factors (EF) of redox-sensitive trace elements in the samples from the stratigraphic sections (Fig. 6) suggest significant authigenic enrichments of these elements (Tribovillard et al., 2006). Moreover, High Spearman´s correlation coefficients between S or TOC and V, Cr, or Ni for 10

ACCEPTED MANUSCRIPT samples from Zorca River (Appendix C-2) also indicate an authigenic –rather than detrital– source for the redox sensitive elements (Ross and Bustin, 2009). In addition to EF values, U/Th, V/Cr,

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Ni/Co, and V/(V +Ni) have been calculated and reported as cross-plots in Figure 7. These redox

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indices give information on the paleo-oxygen level of the depositional environments (e.g., Riquier

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et al., 2006). In each stratigraphic section, most samples are characterized by V/(V+Ni) and U/Th above 0.6 and 1.0, respectively. However, for the V/Cr and Ni/Co ratios, the distinction is not clear. Figure 7

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Shale-normalized trace-element concentrations were similar for samples from the Zorca River and La Molina Mine, showing enrichment in most of the trace elements analyzed. In contrast, Mn was

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depleted. In the Delicias-Villa Páez section, the enrichment pattern differed, with REEs such as La, Nd, Sm, Gd, Er, Yb and Lu being highly enriched or enriched in most samples, while Mn, Cs, Ce,

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Pr, Eu, Tb, Ho and Tm were depleted. Finally, Appendix C-2 shows the Spearman´s correlation coefficients for element pairs in relation to each stratigraphic section, where one of the elements is

5. Discussion

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(including REEs).

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Al or Co (plus TOC or S for Zorca River) and the other is one of the latter or a trace element

5.1. Provenance

The Si/(Si+Al+Ca+Fe) ratio has been used to determine the source of silica in siliceous rocks samples (Ruiz-Ortiz et al., 1989; Halamić et al., 2005); thus, values for this ratio between 0.8 and 0.9 in samples denote silica of predominantly biogenic origin. Si/(Si+Al+Ca+Fe) values of pure and calcareous cherts from the Táchira Ftanita Member were in the 0.87-0.99 and 0.80-0.99 ranges (see Appendix A-1), respectively. These results, together with the identification of numerous recrystallized poorly preserved radiolarian tests in most samples analyzed (Garbán, 2010), indicate that our chert samples originated mainly from diagenetic alteration of biogenic silica derived from radiolarians (Moore, 2008). However, contributions from other sources, such as an input of quartz 11

ACCEPTED MANUSCRIPT dust from arid environments through an eolian transport mechanism (Cecil, 2004), cannot be ruled out. In this respect, the detrital quartz particles present in the samples could be affected by

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dissolution-precipitation, thereby becoming a potential secondary source of silica in the system

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(Garbán, 2010).

Another important issue is the strong negative correlation (Rs) found between CaO and SiO2 contents in the bedded radiolarian cherts studied (see Appendix C-1). This finding is clear evidence

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of diagenetic replacement (silicification) undergone by the original carbonaceous particles and the possible presence of biosilica productivity cycles in the sub-basin under consideration. In addition,

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we observed a strong positive correlation (Rs) between the content of SiO2 and Co. This high positive correlation, together with the low correlation between Co and other elements such as Al,

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Ti, K, Fe, Rb, and Cs (see Appendices C-1 and C-2), as well as Co enrichment in our pure cherts, suggest that Co is closely associated with the migration of biogenic SiO2 during diagenesis into

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beds enriched in silica (Ran et al., 2015). In contrast, high Spearman´s correlation coefficients for element pairs (Appendix C-2), where one of the elements is Al (Fralick and Kronberg, 1997),

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allows confirmation of the relative immobility of lithophile elements such as Rb, Cs, Cr, Y, Ni, V, Th, and REEs (Cullers et al., 1988; Yan et al., 2006). It is therefore possible to use all these elements as indicators of the detrital sediment origin of our chert samples.

Figure 8 also shows the La–Sc–Th ternary diagram, which suggests that most of the samples derived from continental-margin or island-arc intermediate rocks in the La Molina Mine and Delicias-Villa-Páez sections (Bhatia and Crook, 1986). Therefore, our cherts gave values which may indicate a common source with an intermediate composition between mafic and felsic material when comparing them with data reported by Rudnick and Fountain (1995). In addition, various samples from the La Molina Mine lay closer to the granitic composition (see Fig. 8), showing notable proportions of La and low Sc abundances. In contrast, several samples from the Delicias12

ACCEPTED MANUSCRIPT Villa Páez section showed an increase in the abundance of Sc and lay closer to the basaltic composition (see Fig. 8), denoting a greater influence of the mafic contribution.

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Figure 8

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Another diagrammatic representation (Th/Sc versus La/Cr; Piovano et al., 1999) is shown for the

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samples taken from the sections of La Molina Mine and Delicias-Villa Páez (see Fig. 9). In our case, intermediate metamorphic sources yielded sediments of the Táchira Ftanita Member, although other mafic sources can not be ruled out given the Cr/V and Y/Ni values. However, it has been

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demonstrated that metamorphic and granitic rocks exhibit significant differences in numerous metal ratios (Piovano et al., 1999). Despite this drawback, these diagrams have been used as indicators of

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provenance; however, they all must be interpreted with caution. Furthermore, as reported in the literature (e.g., Amstrong-Altrin et al., 2004), mafic and felsic rocks have, respectively, low and

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high LREE/HREE ratios. In our case, LREE values were similar to those of HREE for most of the samples (see Supplementary material I). This finding would indicate that the chert samples derived

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from intermediate (neither mafic nor felsic) rocks. Figure 9

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Figure 10 shows the chondrite-normalized REE profiles (C1; Boynton, 1984) of the three sections sampled. C1-normalized REE concentrations for chert samples from the Zorca River and DeliciasVilla Páez sections exhibited a notable LREE enrichment and a clear negative Eu anomaly, whereas HREE trends were almost flat, except for a negative Yb anomaly (see Supplementary material II). These C1-normalized REE profiles are similar to those reported for sediments derived from sources dominated by old differentiated continental upper crust (Girty et al., 1996). Armstrong et al. (1999) reported similar patterns for chert samples from nearby basins at continental margins where the REE geochemistry is governed by the input of terrigenous detrital material. Moreover, the chondrite-normalized REE profiles for the samples from Zorca River and Delicias-Villa Páez sections are similar to that of Proterozoic intracratonic sediments (mainly associated with the Roraima Fm) from the Guayana Massif, as previously reported by Gibbs et al. (1986). Thus, we 13

ACCEPTED MANUSCRIPT state that the Guayana source supplied particulate detrital material to the cherts analyzed; however, we cannot rule out other possibilities, such as a sedimentary contribution from the Santander Massif

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or other nearby source areas where metamorphic rocks are exposed (Cooper et al., 1995), and the

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distant detrital material became incorporated into the sub-basin by eolian input (Garbán, 2010).

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Figure 10

Most of the samples from the La Molina Mine section exhibited a C1-normalized REE pattern with a slight LREE enrichment and positive Eu anomalies; in contrast, two pure (TLM-050 and TLM-

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145) and some calcareous (TLM-033, TLM-122, TLM-140, and TLM-200) cherts showed negative Eu anomalies (Supplementary material II). According to the literature (e.g., Murray et al., 1991;

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Cole et al., 2014), the latter features could be attributed to an appreciable influence of hydrothermal processes in REE profiles for some chert samples from La Molina Mine section. In this regard, it is

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noteworthy that high Fe and Mn contents in sediments and rocks have been used as indicators of hydrothermal input (Adachi et al., 1986; Yamamoto, 1998). Therefore, the Al/(Al+Fe+Mn) ratio

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can be used to distinguish hydrothermal from non-hydrothermal cherts. Al/(Al+Fe+Mn) values for cherts ranging from 0.30 to 0.37 and from 0.65 to 0.72 (see Appendix B) can denote hydrothermal

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input (Yamamoto, 1987) and the lack of hydrothermal influence (Yamamoto et al., 1997), respectively. Thus, we determined a significant hydrothermal input for a group of chert samples from the central part of the La Molina Mine section (see Fig. 2). The locations of the stratigraphic sections analyzed (Fig. 1) suggest that these latter cherts were influenced by a hydrothermal input, possibly related to existing fracture systems north of the Táchira sub-basin. In fact, Pindell and Kennan (2009) proposed a model that places the paleo-Galapagos hotspot in an area covering the Barinas Basin and the southern part of Lake Maracaibo Basin during Santonian-Campanian times.

5.2. Depositional environment. PAAS-normalized REE patterns (negative Ce anomalies, small Eu anomalies and a slight HREE enrichment compared to LREE) for almost all the samples from the Zorca River, as well as for most 14

ACCEPTED MANUSCRIPT samples from La Molina Mine, suggest a relatively distal (hemipelagic) continental margin environment, with a significant input of terrigenous material (Yamamoto, 1987; Murray, 1994).

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Furthermore, PAAS-normalized REE profiles (small positive Ce anomalies, negative Eu anomalies

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and a negligible LREE enrichment with respect to HREE) for the samples from the Delicias-Villa

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Páez section point to a continental margin depositional environment (Owen et al., 1999), with a strong input of material related to terrigenous detrital sediments.

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Figure 11 shows a modified Lasn/Cesn vs. Al2O3/(Al2O3+Fe2O3) discrimination diagram (Murray, 1994), together with a plot of Ce/Ce* against Eu/Eu* and a mixing diagram between

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LREEn/HREEn and MREEn/HREEn, for chert samples from the three sections studied. Most samples plotted near to or within the continental margin field. However, a large number of samples

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from La Molina Mine, which showed positive Eu anomalies with chondrite-normalized values, did not lie within or near the proximal part to spreading ridge, or the mid-oceanic (pelagic) or

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continental margin fields (see Fig. 11). For the latter samples, showing Al2O3/(Al2O3+Fe2O3) values below 0.4 and Lasn/Cesn around 1, we propose a zonation that may indicate a hydrothermal influence

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on cherts in a depositional setting with significant terrigenous input. Another important aspect is the delimitation of a possible subfield that corresponds to a hemipelagic setting. It should also be noted that the plots of the chert samples from the holostratotype and some samples from La Molina Mine lay within a subfield that overlaps with part of the continental margin field (see Fig. 11). Thus, we can interprete that the variation in Ce anomaly (espressed as Lasn/Cesn) is more sensitive to changes in the input of terrigenous material than the variation in Al2O3/(Al2O3+Fe2O3) for the chert beds addressed here. Figure 11 5.3. Depositional model for chert beds in Táchira According to Racki (1999), dissolved silica for the formation of cherts in the Táchira Ftanita Member derived principally from terrigenous detrital material from exposed areas (mainly the 15

ACCEPTED MANUSCRIPT Guayana Massif) located south of the Depression of Táchira, with an occasional contribution of hydrothermal activity. Therefore, the bedded chert sequence examined in the Táchira sub-basin was

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deposited in a relatively distal paleoenvironment when anoxic events were interrumped by

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upwelling currents in the overlying water column (Erlich et al., 2000). The interpretation of the

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discrimination diagrams proposed by Murray (1994) allowed us to establish a still proximal continental margin (hemipelagic) setting for our samples, with some hydrothermal input in the

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northern part of that sub-basin.

As for the deposition model for the bedded chert sequence studied itself, we postulated that the

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sedimentation of the Táchira Chert Member came about from a modification of the paleooceanographic conditions brought about by changes in weather and atmospheric patterns. These

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changes led to the replacement of a stagnant environment, in which there was a semi-constrained circulation of ocean waters, by a vigorous paleocirculation pattern during the sedimentation of our

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radiolarian cherts (Garbán, 2010). Figure 12 shows the paleogeographic reconstruction model for configuration of the study area during the Late Creataceous. The causes of upwelling regimes in the

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study area during Santonian-Campanian times have not been fully elucidated (see Parrish and Curtis, 1982; Manabe and Bryan, 1985; Rey et al., 2004; among others). Figure 12

Contents of some redox-sensitive trace element in our samples together with TOC, S, other previous geochemical results and chemostratigraphic divisions of the Zorca River section reported by Garbán (2010), suggest a transition from euxinic to low-oxygen marine bottom waters during deposition of the Táchira Chert Member. This agrees with that fact that once the North Equatorial Current upwelling system was active in the Táchira sub-basin during the Santonian-Campanian interval, the oceanic semi-constrained waters began circulating, thereby encouraging vertical flows along the water column (Rey et al., 2004). These new conditions (availability of dissolved O2 and nutrients) would have led to periods of high primary productivity, allowing silica-secreting organisms 16

ACCEPTED MANUSCRIPT (radiolaria) to flourish. Also, high primary productivities, as in cases like the present one, can also give rise to a high rate of consumption of dissolved oxygen by aerobic microorganisms and,

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therefore, the development of oxygen minimum zones below upwelling areas, which would explain

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the suboxic environment near the sediment-water interface (Borchers et al., 2005).

As previously reported in the literature (e.g., Decker, 1991; Tada, 1991), the rhythmic alternation characterizing the sedimentation of the black chert beds in the Táchira Ftanita Member can be

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interpreted from the occurrence of hemicycles of biosilica productivity, which are out of step with hemicycles of carbonatic productivity with a low contribution of detrital material. Such hemicycles

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of biosilica productivity could be controlled by two main factors: changes in the upwelling rate of ocean waters and/or variation in the supply of dissolved silica to the system. Later,the occurrence of

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diagenetic segregation would explain the formation of chert beds (≥ 90% en SiO2) through silicification of the carbonate remains present in the proto-cherts which do not exceed an average

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SiO2 content of 71% (Murray et al., 1992b). Finally, the end of the deposition of the Táchira Chert Member could have resulted from the absence of either of the two aforementioned factors. The

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depositional model established to explain the generation of biosiliceous productivity cycles related to the Táchira Ftanita Member is in coherence with that proposed by Erlich et al. (1996) on the occurrence of episodic upwelling events in the northern part of South America.

6. Conclusions On the basis of our results, we conclude that: - The Guayana Massif appears to have been the main source supplying particulate terrigenous detrital material to black bedded cherts in Táchira, with some hydrothermal contribution from the north of the Táchira sub-basin. The Táchira cherts originate basically from diagenetic alteration of biogenic silica derived from radiolarians.

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ACCEPTED MANUSCRIPT - Most of the chert samples occurred near or within the continental margin field. Also noteworthy is the delimitation of a novel subfield relative to the hemipelagic setting that characterizes the samples

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from the holostratotype and some samples from La Molina Mine.

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- Sedimentation of the Táchira Ftanita Member occurred as a result of climate change, which

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prompted the substitution of a semi-restricted circulation pattern of ocean waters by a vigorous circulation pattern. The rhythmically bedded radiolarian cherts in the Táchira sub-basin can be interpreted from the occurrence of hemicycles of biosilica and carbonatic production with a low

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contribution of detrital material.

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Acknowledgments

This research was funded by the Consejode Desarrollo Científico y Humanístico (Universidad

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Central de Venezuela), through the project 03.00.5661/07.

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ACCEPTED MANUSCRIPT Villamil, T., Arango, C., Hay, W., 1999, Plate tectonic paleoceanographic hypothesis for Cretaceous source rocks and cherts of northern South America. Geological Society of America,

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Special Paper 332, 191–202.

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Wedepohl, K., 1991. The composition of the upper Earth's crust and the natural cycles of selected metals. In: Merian, E. (Ed.), Metals and their compounds in theenvironment. VCH-

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Verlagsgesellschaft, Weinheim, pp. 3–17.

Yamamoto, K., 1987. Geochemical characteristics and depositional environments of cherts and

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associated rocks in the Franciscan and Shimanto Terranes. Sedimentary Geology 52, 65–108.

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Yamamoto, K., 1998. A possible mechanism of rhythmic alternation of bedded cherts revealed by

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their chemical composition. Journal of Earth and Planetary Sciences, Nagoya University, 45, 29–39.

Yamamoto, K., Nakamaru, K., Adachi, M., 1997. Depositional environments of “accreted bedded

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cherts” in the Shimanto terrane, Southwest Japan, on the basis of major and minor element compositions. Journal of Earth and Planetary Science, Nagoya University, 44, 1–19.

Yan, Y., Xia, B., Lin, G., Cui, X., Hu, X., Yna, P., Zhang, F., 2006. Geochemistry of the sedimentary rocks from the Nanxiong Basin, South China and implications for provenance, paleoenvironment and paleoclimate at the K/T boundary. Sedimentary Geology 197, 127–140.

Yu, B., Dong, H., Widom, E., Chen, J., and Lin, Ch., 2009, Geochemistry of basal Cambrian black shales and cherts from the Northern Tarim Basin, Northwest China: Implications for depositional setting and tectonic history. Journal of Asian Earth Sciences 34, 418–436.

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ACCEPTED MANUSCRIPT Figure captions Fig. 1: a) Worldwide palaeogeographic map of the Middle Cretaceous (Vrielynck and Bouysse, 2003) showing the location of the succession studied herein; b) map showing the location of the three sampling sites in the Táchira State.

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Fig. 2: stratigraphic column in the Táchira sub-basin.

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Figure 3: Stratigraphic position of each sample in the respective section.

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Fig. 4: a), b), c), and d) PAAS-normalized REE patterns for most of the pure cherts, TZF-160 and TZF-280, and calcareous cherts from the holostratotype.

Fig. 5: a), b), and c), respectively, PAAS-normalized REE patterns for the pure and calcareouschertsfrom the La Molina Mine, as well as the purechertsfrom the Delicias-Villa Páez section.

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Figure 6: Box plots of the enrichment factors (EF) of redox-sensitive elements (Co, U, V, Ba, Ni, Cr, Fe, and Mn) from pure cherts (PC) and calcareus cherts (CC) of the three sections studied.

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Fig. 7. Crossplot of redox indices: V/Cr vs. Ni/Co and V/(V+Ni) vs. U/Th.

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Figure 8: La–Sc–Th diagram showing the distribution of chert samples derived from mafic and intermediante rocks in the two parastratotypes. We included data from upper continental crust (Taylor and McLennan, 1985) and Roraima Fm (Gibbs et al., 1986).

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Fig. 9: Th/Sc against La/Cr diagram for chert samples from the Táchira Ftanita Member.

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Fig. 10: a), b), and c), respectively, C1-normalized REE patterns for the sampled cherts from the Zorca River, La Molina Mine (except TZF-140 and TZF-145), and Delicias-Villa Páez sections.

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Figure 11: Lan/Cen versus Al2O3/(Al2O3+Fe2O3) discrimination diagram, plot of Ce/Ce* against Eu/Eu*, and mixing diagram between LREEn/HREEn and MREEn/HREEn (LREEn=Lan+Prn+Ndn, MREEn=Smn+Eun+Tbn, and HREEn=Hon+Ybn+Lun) for chert samples from the three sections studied. Figure 12: Schematic representation of model for the deposition of the Táchira Chert Member in the study area.

Appendix A: TOC, sulfur, major and minor element contents (wt.%; A-1), rare earth element concentrations (mg/Kg; A-2), and trace-element concentrations (mg/Kg; A-3) in the chert samples.

Appendix B: Stratigraphic profiles of some proxies in the three sections studied.

Appendix C: Correlation matrices for Mn, Co, and major elements (C-1) and coefficients (Rs) between Al2O3 and Co (plus TOC and S for Zorca River) and trace elements (even REEs) studied (C-2) for the three sampling sites.

Supplementary material I: PAAS-normalized REE abundances for the samples and elemental concentrations (mg/Kg) of the PAAS standard. Supplementary material II: C1-normalized concentrations (mg/Kg) of REEs for the samples and elemental composition (μg/Kg) of the chondrite standard.

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Na2O 0.15 0.18 0.09 0.12 0.09 0.08 0.23 0.27 0.11 0.12 0.08 0.12 0.12 0.09 0.12 0.16 0.22 0.614 0.12 0.65 0.11 0.23 0.646 0.11 0.16 0.124 0.13 0.12 0.137 0.12 0.42 0.289 0.09 0.07 0.995 0.09 0.06 0.039 0.09 0.12 0.126 0.09 0.12 0.172 0.11 0.18 1.047 0.09 0.07 0.119 0.09 0.08 0.105 0.09 0.11 0.243 0.08 0.13 0.112 0.09 0.22 0.135 0.11 0.16 0.188 0.08 0.582 0.11 0.36 0.156 0.10 0.21 0.06 0.06 0.11 0.07 0.06 0.06 0.07 0.05 0.09 0.05 0.050 0.34 0.02 0.085 0.08 0.66 0.034 0.19 0.07 3.522 0.25 0.22 0.028 0.10 0.33 0.173 0.07 0.11 0.324 0.05 0.08 0.233 0.09 0.399 0.341 0.10 0.04 0.03 0.243 0.13 0.16 2.709 0.15 0.13 0.13 0.16

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MgO 0.22 0.20 0.08 0.15 0.09 0.02 0.12 0.03 0.09 0.58 0.08 0.17 0.23 0.17 0.27 0.20 0.11 0.12 0.13 0.08 0.18 0.12 0.61 0.12 0.18 0.09 0.30 0.12 0.16 0.13 0.22 0.20 0.614 0.12 0.65 0.527 0.13 0.11 0.23 0.646 0.18 0.11 0.16 0.124 0.05 0.13 0.12 0.137 0.03 0.12 0.42 0.289 0.05 0.09 0.07 0.995 0.13 0.09 0.06 0.039 0.08 0.09 0.12 0.126 0.03 0.09 0.12 0.172 0.08 0.11 0.18 1.047 0.05 0.07 0.119 0.10 0.09 0.105 0.10 0.09 0.11 0.13 0.08 0.112 0.03 0.09 0.22 0.135 0.11 0.16 0.188 0.12 0.23 0.08 0.582 0.11 0.156 0.16 0.07 0.09 0.05 0.10 0.10 0.10 0.09 0.06 0.02 0.07 0.05 0.41 0.09 0.05 0.050 0.11 0.34 0.02 0.085 0.20 0.08 0.66 0.034 0.23 0.19 0.07 3.522 0.16 0.22 0.028 0.15 0.10 0.173 0.10 0.07 0.11 0.07 0.02 0.08 0.233 0.22 0.09 0.399 0.341 0.10 0.04 0.11 0.12 0.03 0.243 0.12 2.709 0.06 0.04 0.57

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CaO 5.50 7.18 3.30 3.99 1.60 3.17 0.44 16.79 14.92 12.42 5.90 8.93 14.50 15.55 7.74 0.61 11.77 0.527 0.09 8.13 0.30 0.16 5.18 0.12 0.22 0.614 9.68 0.11 0.23 0.65 13.97 0.13 0.16 0.124 0.646 3.30 0.18 0.11 0.137 2.12 0.05 0.13 0.12 5.04 0.03 0.12 0.42 0.289 8.10 0.05 0.09 0.07 0.995 6.04 0.13 0.09 0.06 0.039 2.49 0.08 0.09 0.12 0.126 4.30 0.03 0.09 0.12 0.172 4.69 0.08 0.11 0.18 1.047 2.58 0.09 0.07 0.119 3.76 0.10 0.08 0.105 13.61 0.10 0.09 0.243 2.56 0.13 0.08 0.03 0.09 0.22 0.135 7.66 12.41 0.11 0.16 0.188 2.99 0.08 0.582 7.16 0.156 0.92 0.32 0.30 2.03 0.52 2.07 1.30 0.10 1.52 0.09 0.06 11.38 0.02 0.07 0.05 1.58 0.41 0.09 0.05 0.050 11.17 0.11 0.34 0.02 0.085 9.11 0.20 0.08 0.66 0.034 10.58 0.23 0.19 0.07 3.522 9.03 0.16 0.25 0.22 0.028 0.64 0.15 0.10 0.33 0.173 13.13 0.10 0.07 0.11 0.324 18.73 0.07 0.05 0.08 0.233 0.22 0.09 0.02 0.341 6.28 7.05 0.10 0.04 0.399 10.83 0.03 0.243 1.07 2.709 1.46 5.62

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Fe2O3 0.30 0.31 0.13 0.23 0.14 0.13 1.82 0.51 0.34 16.79 0.27 14.92 0.14 12.42 0.40 0.41 8.93 0.24 14.50 0.26 15.55 0.92 7.74 0.61 0.30 11.77 0.18 0.09 0.19 8.13 0.30 0.12 0.16 0.21 5.18 0.13 0.22 0.20 0.614 0.53 9.68 0.12 0.65 0.527 0.13 13.97 0.11 0.23 0.646 0.13 3.30 0.18 0.11 0.16 0.124 0.17 2.12 0.05 0.13 0.12 0.137 0.19 5.04 0.03 0.12 0.42 0.289 0.27 8.10 0.05 0.09 0.07 0.995 0.16 6.04 0.13 0.09 0.06 0.039 0.19 2.49 0.08 0.09 0.12 0.126 0.17 4.30 0.03 0.09 0.12 0.172 0.17 4.69 0.08 0.11 0.18 1.047 0.31 2.58 0.05 0.09 0.07 0.119 0.34 3.76 0.10 0.09 0.08 0.105 0.14 13.61 0.10 0.09 0.11 0.243 2.56 0.13 0.08 0.112 0.27 0.65 0.03 0.09 0.22 0.135 0.19 0.11 0.16 0.188 0.34 0.08 0.582 0.09 0.156 0.10 0.16 0.13 0.18 0.13 0.14 2.07 0.12 1.30 0.10 1.26 1.52 0.09 0.06 0.21 11.38 0.02 0.07 0.05 0.49 1.58 0.41 0.09 0.05 0.050 0.77 11.17 0.11 0.34 0.02 0.085 0.27 9.11 0.20 0.08 0.66 0.034 0.18 10.58 0.23 0.19 0.07 3.522 0.09 9.03 0.16 0.25 0.22 0.028 0.14 0.64 0.15 0.10 0.33 0.173 0.12 13.13 0.10 0.07 0.11 0.324 18.73 0.07 0.05 0.08 0.233 0.16 0.43 0.22 0.09 0.02 0.341 0.35 0.10 0.04 0.399 0.19 0.03 0.243 0.18 2.709 0.28

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TiO2 0.03 0.03 0.02 0.03 0.02 0.02 0.42 0.05 0.05 0.03 0.02 0.05 0.07 0.03 0.03 0.24 0.12 0.26 15.55 0.05 0.92 7.74 0.61 0.03 0.30 11.77 0.18 0.09 0.02 0.19 8.13 0.30 0.12 0.16 0.07 0.21 5.18 0.13 0.22 0.20 0.614 0.02 0.53 9.68 0.12 0.65 0.527 0.02 0.13 13.97 0.11 0.23 0.646 0.02 0.13 3.30 0.18 0.11 0.16 0.124 0.02 0.17 2.12 0.05 0.13 0.12 0.137 0.03 0.19 5.04 0.12 0.42 0.289 0.02 0.27 8.10 0.05 0.09 0.07 0.995 0.02 6.04 0.13 0.09 0.06 0.039 0.03 0.19 0.08 0.09 0.12 0.126 0.03 0.17 4.30 0.09 0.12 0.172 0.05 0.17 4.69 0.08 0.18 1.047 0.05 0.31 2.58 0.09 0.119 0.03 0.34 3.76 0.10 0.09 0.08 0.14 13.61 0.10 0.09 0.11 0.243 0.04 0.08 2.56 0.13 0.112 0.03 0.09 0.22 0.135 0.05 0.11 0.16 0.188 0.02 0.08 0.582 0.01 0.156 0.01 0.02 0.02 0.02 0.02 0.13 0.01 0.14 2.07 0.18 0.12 1.30 0.10 0.03 1.26 1.52 0.09 0.06 0.06 0.21 11.38 0.02 0.07 0.05 0.09 0.49 1.58 0.41 0.05 0.050 0.04 0.77 11.17 0.11 0.34 0.02 0.085 0.02 0.27 9.11 0.20 0.08 0.66 0.034 0.01 0.18 10.58 0.23 0.19 0.07 3.522 0.01 0.09 9.03 0.16 0.25 0.22 0.028 0.01 0.14 0.64 0.15 0.10 0.33 0.173 0.12 13.13 0.10 0.07 0.11 0.324 0.02 0.04 18.73 0.07 0.05 0.08 0.233 0.04 0.22 0.09 0.02 0.341 0.02 0.10 0.04 0.399 0.01 0.03 0.243 0.03 2.709

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Al2O3 1.70 1.61 0.89 1.30 0.02 0.60 0.03 0.59 0.02 9.03 0.02 2.44 0.42 2.21 0.05 1.38 0.05 0.60 0.03 2.25 0.02 1.95 0.05 1.04 0.07 1.55 0.03 4.46 0.03 0.24 1.66 0.12 0.26 15.55 1.11 0.05 0.92 7.74 0.61 1.08 0.03 0.30 11.77 0.18 0.09 2.42 0.02 0.19 8.13 0.30 0.12 0.16 0.62 0.07 0.21 5.18 0.13 0.22 0.20 0.614 0.68 0.02 0.53 9.68 0.12 0.65 0.527 0.79 0.02 0.13 13.97 0.11 0.23 0.646 0.66 0.02 0.13 3.30 0.18 0.11 0.16 0.124 1.19 0.02 0.17 2.12 0.05 0.13 0.12 0.137 0.79 0.03 0.19 5.04 0.12 0.42 0.289 0.91 0.02 0.27 8.10 0.05 0.09 0.07 0.995 0.87 0.02 0.16 6.04 0.13 0.09 0.06 0.039 1.25 0.03 0.19 2.49 0.08 0.09 0.12 0.126 2.02 0.03 0.17 4.30 0.09 0.12 0.172 1.42 0.05 0.17 4.69 0.08 0.11 0.18 1.047 0.83 0.05 0.31 2.58 0.09 0.07 0.119 0.03 0.34 3.76 0.10 0.09 0.08 0.105 0.68 3.06 0.14 13.61 0.10 0.09 0.11 0.243 0.76 2.56 0.13 0.08 0.112 1.70 0.03 0.09 0.22 0.135 0.05 0.11 0.16 0.188 0.00 0.08 0.582 0.29 0.156 0.16 0.00 0.03 0.01 0.02 0.08 0.02 0.13 6.03 0.01 0.14 2.07 0.28 0.18 0.12 1.30 0.10 1.77 0.03 1.26 1.52 0.09 0.06 3.58 0.06 0.21 11.38 0.02 0.07 0.05 0.74 0.09 0.49 1.58 0.41 0.05 0.050 0.58 0.04 0.77 11.17 0.11 0.34 0.02 0.085 0.00 0.02 0.27 9.11 0.20 0.08 0.66 0.034 0.35 0.01 0.18 10.58 0.23 0.19 0.07 3.522 0.31 0.01 0.09 9.03 0.16 0.25 0.22 0.028 0.01 0.14 0.64 0.15 0.10 0.33 0.173 0.63 1.25 0.12 13.13 0.10 0.07 0.11 0.324 1.45 18.73 0.07 0.05 0.08 0.233 0.40 0.22 0.09 0.02 0.341 0.24 0.10 0.04 0.399 0.85 0.03 0.243 2.709

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SiO2 87.49 84.51 92.66 90.77 96.08 93.32 84.55 66.01 70.13 75.45 88.36 80.63 70.91 70.00 83.73 1.04 72.08 1.55 0.03 82.78 4.46 0.03 0.24 88.96 1.66 0.12 0.26 15.55 80.95 1.11 0.05 0.92 7.74 0.61 71.22 1.08 0.03 0.30 11.77 0.18 0.09 93.00 2.42 0.02 0.19 8.13 0.30 0.12 0.16 95.11 0.62 0.07 0.21 5.18 0.13 0.22 0.20 0.614 89.65 0.68 0.02 0.53 9.68 0.12 0.65 0.527 84.29 0.79 0.02 0.13 13.97 0.11 0.23 0.646 87.19 0.66 0.02 0.13 3.30 0.18 0.11 0.16 0.124 94.24 1.19 0.02 0.17 2.12 0.05 0.13 0.12 0.137 90.83 0.02 0.03 0.19 5.04 0.12 0.42 0.289 90.18 0.91 0.16 0.27 8.10 0.05 0.09 0.07 0.995 93.49 0.87 0.02 2.49 6.04 0.13 0.09 0.06 0.039 90.39 1.25 0.03 0.19 0.08 0.09 0.12 0.126 73.33 2.02 0.03 0.17 4.30 0.11 0.09 0.12 0.172 94.08 1.42 0.05 0.17 4.69 0.08 0.07 0.18 1.047 0.83 0.05 0.31 2.58 0.09 0.105 85.88 0.119 77.76 0.03 0.34 3.76 0.10 0.09 0.08 80.88 0.14 13.61 0.10 0.09 0.11 0.243 86.43 2.56 0.13 0.08 0.112 95.01 0.03 0.09 0.22 0.135 89.58 0.11 0.16 0.188 96.71 0.08 0.582 94.20 0.156 93.89 86.72 87.41 0.03 98.79 0.01 0.02 76.32 0.08 0.02 0.13 85.74 6.03 0.01 0.14 2.07 75.25 0.28 0.18 0.12 1.30 0.10 78.64 1.77 0.03 1.26 1.52 0.09 0.06 81.92 3.58 0.06 0.21 11.38 0.02 0.07 0.05 80.01 0.74 0.09 0.49 1.58 0.41 0.05 0.050 87.75 0.58 0.04 0.77 11.17 0.11 0.34 0.02 0.085 80.52 0.00 0.02 0.27 9.11 0.20 0.08 0.66 0.034 73.64 0.35 0.01 0.18 10.58 0.23 0.19 0.07 3.522 0.31 0.01 0.09 9.03 0.16 0.25 91.28 0.22 0.028 88.03 0.01 0.14 0.64 0.15 0.10 0.33 0.173 83.12 0.12 13.13 0.10 0.07 0.11 0.324 96.80 18.73 0.07 0.05 0.08 0.233 96.53 0.22 0.09 0.02 0.341 91.39 0.10 0.04 0.399 0.03 0.243 2.709

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Height 13.0 15.0 19.0 21.5 92.66 24.0 90.77 25.0 96.08 31.0 93.32 33.0 84.55 39.0 66.01 40.0 70.13 42.0 75.45 43.0 88.36 44.0 80.63 46.0 70.91 48.0 1.04 50.0 83.73 0.03 51.0 72.08 1.55 0.24 55.0 82.78 4.46 0.03 15.55 57.0 88.96 1.66 0.12 0.26 0.61 59.0 80.95 1.11 0.05 0.92 7.74 0.09 61.0 71.22 1.08 0.03 0.30 11.77 0.18 0.16 63.0 93.00 2.42 0.02 0.19 8.13 0.30 0.12 0.614 65.0 95.11 0.62 0.07 0.21 5.18 0.13 0.22 0.20 67.0 89.65 0.68 0.02 0.53 9.68 0.12 0.65 0.527 69.0 84.29 0.79 0.02 0.13 13.97 0.11 0.23 0.646 71.0 87.19 0.66 0.02 0.13 3.30 0.18 0.11 0.16 0.124 73.0 94.24 1.19 0.02 0.17 2.12 0.05 0.13 0.12 0.137 74.0 90.83 0.79 0.03 0.19 5.04 0.12 0.42 0.289 76.0 90.18 0.91 0.02 0.27 8.10 0.05 0.09 0.07 0.995 77.0 93.49 0.87 0.02 0.16 6.04 0.13 0.09 0.06 0.039 79.0 90.39 1.25 0.03 0.19 2.49 0.08 0.09 0.12 0.126 81.0 73.33 2.02 0.03 0.17 4.30 0.09 0.12 0.172 94.08 1.42 0.05 0.17 4.69 0.08 0.11 13.0 0.18 1.047 16.0 0.83 0.05 0.31 2.58 0.09 0.07 0.119 17.0 0.03 0.34 3.76 0.10 0.09 0.08 0.105 18.0 0.14 13.61 0.10 0.09 0.11 0.243 19.0 2.56 0.13 0.08 0.112 21.0 0.03 0.09 0.22 0.135 22.0 0.11 0.16 0.188 23.0 0.08 0.582 24.0 0.156 25.0 26.0 86.72 27.0 87.41 0.03 28.0 98.79 0.01 0.02 30.0 76.32 0.08 0.02 0.13 31.0 85.74 6.03 0.01 0.14 2.07 32.0 75.25 0.28 0.18 0.12 1.30 0.10 33.0 78.64 1.77 0.03 1.26 1.52 0.09 0.06 34.0 81.92 3.58 0.06 0.21 11.38 0.02 0.07 0.05 43.5 79.99 0.74 0.09 0.49 1.58 0.41 0.05 0.050 46.0 87.75 0.58 0.04 0.77 11.17 0.11 0.34 0.02 0.085 49.5 80.52 0.00 0.02 0.27 9.11 0.20 0.08 0.66 0.034 73.64 0.35 0.01 0.18 10.58 0.23 0.19 0.0 0.07 3.522 1.0 0.31 0.01 0.09 9.03 0.16 0.25 0.22 0.028 3.0 0.01 0.14 0.64 0.15 0.10 0.33 0.173 5.0 0.12 13.13 0.10 0.07 0.11 0.324 6.0 18.73 0.07 0.05 0.08 0.233 7.0 0.22 0.09 0.02 0.341 0.10 0.04 0.399 0.03 0.243 2.709

AC

TZF-070 TZF-080 TZF-100 TZF-114 TZF-125 TZF-130 TZF-160 TZF-170 TZF-200 TZF-205 TZF-215 TZF-220 TZF-225 TZF-235 TZF-245 TZF-255 TZF-260 TZF-280 TZF-290 TZF-300 TZF-310 TZF-320 TZF-330 TZF-340 TZF-350 TZF-360 TZF-370 TZF-375 TZF-385 TZF-390 TZF-400 TZF-410 TLM-215 TLM-200 TLM-195 TLM-190 TLM-185 TLM-175 TLM-170 TLM-165 TLM-160 TLM-155 TLM-150 TLM-145 TLM-140 TLM-130 TLM-125 TLM-122 TLM-115 TLM-110 TLM-063 TLM-050 TLM-033 TVP-210 TVP-205 TVP-195 TVP-185 TVP-180 TVP-175

K2O 0.18 0.16 0.10 0.11 0.080 0.08 0.176 0.08 0.034 2.05 0.044 0.41 0.050 0.25 2.051 0.19 0.862 0.08 0.779 0.30 0.151 0.30 0.261 0.16 0.477 0.20 0.614 0.65 0.527 0.23 0.646 0.16 0.124 0.12 0.137 0.42 0.289 0.07 0.995 0.06 0.039 0.12 0.126 0.12 0.172 0.18 1.047 0.07 0.119 0.08 0.105 0.11 0.13 0.112 0.22 0.135 0.16 0.188 0.08 0.582 0.156 0.08 0.26 0.11 0.14 0.03 0.03 0.03 0.05 0.05 0.05 0.05 0.050 0.02 0.085 0.66 0.034 0.07 3.522 0.22 0.028 0.33 0.173 0.11 0.324 0.08 0.233 0.02 0.341 0.04 0.03 0.243 2.709 0.06 0.15 0.16 0.04 0.03 0.10

P 2O 5 0.105 0.060 0.080 0.176 0.034 0.044 0.050 2.051 0.862 0.779 0.151 0.261 0.477 0.614 0.527 0.646 0.124 0.137 0.289 0.995 0.039 0.126 0.172 1.047 0.119 0.105 0.243 0.112 0.135 0.188 0.582 0.156 0.074 0.235 0.049 0.187 0.040 0.059 0.034 0.060 0.020 0.050 0.085 0.034 3.522 0.028 0.173 0.324 0.233 0.341 0.399 0.243 2.709 0.063 0.205 0.275 0.285 0.062 0.171

ACCEPTED MANUSCRIPT Fe2O3 0.16 0.10 0.26 0.22 0.10 0.14 0.12 0.19 0.09 0.13 0.13 0.17 0.13 0.01

CaO 6.47 0.66 10.05 12.22 3.12 1.92 2.01 5.03 2.77 3.30 9.90 1.08 0.00 0.01

MA D TE CE P AC

44

MgO 0.05 0.05 1.32 0.45 0.02 0.08 0.24 0.07 0.04 0.04 0.06 0.04 0.01 0.01

Na2O 0.12 0.12 0.16 0.15 0.09 0.10 0.10 0.11 0.11 0.10 0.11 0.10 0.08 0.01

T

TiO2 0.01 0.01 0.03 0.03 0.01 0.01 0.01 0.03 0.01 0.02 0.01 0.02 0.02 0.01

IP

Al2O3 0.36 0.19 0.95 0.95 0.15 0.30 0.21 1.00 0.13 0.40 0.30 0.64 0.27 0.01

SC R

SiO2 90.57 94.99 82.02 80.83 94.67 93.96 91.85 87.36 93.23 93.09 87.02 91.38 98.77 0.01

NU

Height TVP-170 8.0 TVP-165 9.0 TVP-160 10.0 TVP-155 11.0 TVP-150 12.0 TVP-140 14.0 TVP-135 15.0 TVP-130 16.0 TVP-125 17.0 TVP-120 18.0 TVP-115 19.0 TVP-110 20.0 TVP-105 21.0 LOD -Note: LOD=limit of detection

K2O 0.04 0.02 0.09 0.11 0.02 0.03 0.03 0.09 0.02 0.04 0.03 0.05 0.03 0.01

P 2O 5 0.227 0.108 0.247 0.624 0.085 0.027 0.063 0.191 0.413 0.070 0.123 0.130 0.149 0.001

ACCEPTED MANUSCRIPT Table 2: Correlation matrices among major elements and Co for the three sampling sites Zorca River TiO2 -0.22 0.93 1.00

Fe2O3 -0.40 0.93 0.84 1.00

SiO2 1.00

Al2O3 -0.07 1.00

TiO2 -0.01 0.96 1.00

Fe2O3 -0.03 0.97 0.96 1.00

CaO -0.99 0.16 0.07 0.26 1.00

MgO -0.58 0.58 0.58 0.60 0.50 1.00

La Molina Mine

K2O -0.29 0.95 0.96 0.90 0.14 0.58 0.47 1.00

P2O5 -0.49 0.10 -0.04 0.14 0.50 0.07 0.57 0.10 1.00

Co 0.67 -0.51 -0.41 -0.51 -0.62 -0.48 -0.48 -0.47 -0.31 1.00

Na2O -0.01 0.70 0.67 0.71 0.00 0.04 1.00

K2O -0.06 0.94 0.96 0.93 0.08 0.28 0.59 1.00

P2O5 -0.42 -0.05 -0.10 0.03 0.40 -0.01 0.27 -0.07 1.00

Co 0.08 -0.56 -0.51 -0.54 -0.14 -0.13 -0.41 -0.53 -0.08 1.00

Na2O -0.81 0.06 0.13 0.13 0.81 0.26 1.00

K2O -0.32 0.82 0.88 0.78 0.23 0.20 0.41 1.00

P2O5 -0.65 -0.02 0.01 -0.02 0.65 -0.01 0.83 0.18 1.00

Co 0.30 -0.27 -0.29 -0.30 -0.29 -0.27 -0.33 -0.40 -0.21 1.00

MA

NU

MgO -0.78 0.31 0.27 0.25 0.76 1.00

D TE

SiO2 Al2O3 TiO2 Fe2O3 CaO MgO Na2O K2O P 2O 5 Co

CaO -0.99 0.09 0.01 0.04 1.00

Na2O -0.51 0.55 0.43 0.50 0.44 0.41 1.00

T

Al2O3 -0.31 1.00

IP

SiO2 1.00

SC R

SiO2 Al2O3 TiO2 Fe2O3 CaO MgO Na2O K2O P 2O 5 Co

Delicias-Villa Páez section Al2O3 -0.03 1.00

TiO2 -0.08 0.96 1.00

Fe2O3 -0.07 0.84 0.84 1.00

CE P

SiO2 1.00

AC

SiO2 Al2O3 TiO2 Fe2O3 CaO MgO Na2O K2O P 2O 5 Co

CaO -0.98 -0.11 -0.06 -0.05 1.00

MgO -0.22 0.08 0.12 0.09 0.22 1.00

45

ACCEPTED MANUSCRIPT

Pr

Nd

Sm

Eu

Gd

Tb

Dy

Ho

Er

Tm

Yb

Lu

4.9

8.3

1.0

3.4

0.7

0.13

0.6

0.1

0.5

0.1

0.3

0.1

0.1

0.1

5.2

8.8

1.1

3.4

0.7

0.14

0.7

0.1

0.6

0.1

0.4

0.1

0.1

0.1

2.0

2.9

0.4

1.2

0.2

0.03

0.2

0.1

0.2

0.1

0.1

0.1

0.1

0.1

3.4

4.7

0.6

2.1

0.4

0.08

0.4

0.1

0.4

0.1

0.3

0.1

0.1

0.1

1.6

2.4

0.3

0.9

0.2

0.03

0.1

0.5

0.1

0.1

0.1

0.1

0.1

0.1

1.9

2.9

0.3

1.1

0.2

0.03

0.2

0.1

0.2

0.1

0.1

0.1

0.1

0.1

35.7

65.5

8.3

25.7

3.8

0.37

1.2

0.2

1.2

0.3

0.9

0.2

1.0

0.1

18.8

26.5

3.7

13.1

2.5

0.51

2.6

0.4

2.5

0.6

1.6

0.2

1.2

0.2

5.6

9.0

1.2

3.8

0.7

0.14

0.6

0.1

0.6

0.1

0.4

0.1

0.3

0.1

7.0

9.1

1.1

3.6

0.7

0.13

0.7

0.1

0.7

0.2

0.6

0.1

0.4

0.1

2.2

3.3

0.4

1.4

0.3

0.05

0.2

0.1

0.3

0.1

0.2

0.1

0.1

0.1

7.0

10.6

1.5

5.0

0.9

0.19

0.9

0.1

0.9

0.2

0.6

0.1

0.4

0.1

9.6

12.8

1.8

6.2

1.1

0.23

1.2

0.2

1.2

0.3

0.8

0.1

0.6

0.1

4.9

6.4

0.9

3.2

0.6

0.13

0.7

0.1

0.7

0.2

0.5

0.1

0.2

0.1

6.7

10.3

1.3

4.4

0.8

0.16

0.8

0.1

0.8

0.2

0.5

0.1

0.3

0.1

16.0

24.9

3.2

10.5

1.9

0.35

1.7

0.3

1.7

0.4

1.1

0.2

0.9

0.1

5.8

10.3

1.2

4.1

0.8

0.14

0.7

0.1

0.6

0.1

0.4

0.1

0.2

0.1

15.2

15.5

0.5

1.6

0.3

0.06

0.3

0.1

0.3

0.1

0.2

0.1

0.1

0.1

4.3

0.6

1.8

0.3

0.06

0.3

0.1

0.3

0.1

0.2

0.1

0.1

0.1

15.1

2.0

6.4

1.1

0.22

1.1

0.2

1.0

0.2

0.7

0.1

0.6

0.1

2.0

3.5

0.4

1.4

0.3

0.05

0.2

0.1

0.3

0.1

0.2

0.1

0.1

0.1

1.8

2.7

0.3

1.2

0.2

0.03

0.2

0.1

0.2

0.1

0.2

0.1

0.1

0.1

3.0

4.9

0.6

1.9

0.4

0.07

0.3

0.1

0.3

0.1

0.2

0.1

0.1

0.1

7.2

10.6

1.3

4.7

0.9

0.18

1.0

0.1

1.0

0.2

0.7

0.1

0.5

0.1

3.7

6.5

0.8

2.7

0.5

0.09

0.5

0.1

0.5

0.1

0.3

0.1

0.1

0.1

2.0

3.4

0.4

1.4

0.3

0.05

0.2

0.1

0.2

0.1

0.2

0.1

0.1

0.1

3.0

4.7

0.6

2.2

0.4

0.09

0.4

0.1

0.4

0.1

0.3

0.1

0.1

0.1

2.9

5.0

0.6

2.0

0.4

0.07

0.3

0.1

0.3

0.1

0.2

0.1

0.1

0.1

4.0

7.2

0.9

2.8

0.5

0.10

0.4

0.1

0.4

0.1

0.3

0.1

0.1

0.1

2.8 9.2

D

TE

CE P

SC R

NU

MA 46

IP

Ce

AC

TZF070 TZF080 TZF100 TZF114 TZF125 TZF130 TZF160 TZF170 TZF200 TZF205 TZF215 TZF220 TZF225 TZF235 TZF245 TZF255 TZF260 TZF280 TZF290 TZF300 TZF310 TZF320 TZF330 TZF340 TZF350 TZF360 TZF370 TZF375 TZF-

La

T

Table 3: Rare earth element concentration (mg/Kg) in all the chert samples

1.5

4.9

0.9

0.18

0.8

0.1

0.8

0.2

0.5

0.1

0.3

0.1

7.3

11.9

1.5

5.1

1.0

0.18

0.9

0.1

1.0

0.2

0.7

0.1

0.6

0.1

2.5

4.1

0.5

1.6

0.3

0.06

0.3

0.1

0.3

0.1

0.2

0.1

0.1

0.1

5.5

9.4

1.1

5.2

1.0

0.41

0.8

0.2

0.8

0.1

0.2

0.1

0.2

0.1

7.3

11.8

1.4

6.6

1.4

0.38

1.1

0.2

1.1

0.2

0.4

0.1

0.4

0.1

3.9

7.3

0.7

2.7

0.6

0.46

0.4

6.2

10.6

1.3

6.2

1.4

0.46

1.2

La

Ce

Pr

Nd

Sm

Eu

Gd

2.2

4.4

0.3

1.3

0.3

0.12

0.1

2.0

4.0

0.3

1.1

0.3

0.10

3.1

8.2

0.6

2.5

0.5

0.15

2.6

4.8

0.4

1.6

0.3

2.3

4.4

0.3

1.2

0.2

2.2

4.4

0.3

1.3

0.3

2.4

4.6

0.3

1.4

2.4

7.5

0.5

2.2

33.9

69.2

3.0

5.8

7.6

11.9

SC R

IP

11.5

0.7

0.1

0.2

0.1

0.2

0.1

0.2

1.2

0.2

0.4

0.1

0.4

0.1

Tb

Dy

Ho

Er

Tm

Yb

Lu

0.1

0.4

0.1

0.1

0.1

0.1

0.1

0.1

0.1

0.4

0.1

0.1

0.1

0.1

0.1

0.4

0.1

0.3

0.1

0.1

0.1

0.1

0.1

0.17

0.2

0.1

0.5

0.1

0.1

0.1

0.1

0.1

0.10

0.1

0.1

0.4

0.1

0.1

0.1

0.1

0.1

0.13

0.2

0.1

0.4

0.1

0.1

0.1

0.1

0.1

0.3

0.14

0.2

0.1

0.4

0.1

0.1

0.1

0.1

0.1

0.4

0.03

0.3

0.1

0.3

0.1

0.1

0.1

0.1

0.1

D

MA

NU

0.1

TE

CE P

TLM185 TLM175 TLM170 TLM165 TLM160 TLM155 TLM150 TLM145 TLM140 TLM130 TLM125 TLM122 TLM115 TLM110 TLM063 TLM050 TLM033 TVP210 TVP205 TVP195 TVP185 TVP-

6.4

7.0

30.3

6.1

0.98

5.1

0.8

4.5

0.9

3.1

0.5

2.5

0.4

0.5

1.9

0.4

0.17

0.2

0.1

0.5

0.1

0.1

0.1

0.1

0.1

1.6

6.9

1.4

0.62

1.0

0.2

1.1

0.2

0.6

0.1

0.6

0.1

26.4

2.5

12.9

3.3

0.87

2.7

0.5

2.7

0.5

1.3

0.2

1.0

0.1

7.2

0.7

2.8

0.6

0.20

0.4

0.1

0.7

0.1

0.2

0.1

0.3

0.1

3.4

6.8

0.7

2.8

0.6

0.20

0.4

0.1

0.7

0.1

0.3

0.1

0.3

0.1

2.4

3.9

0.3

1.2

0.3

0.12

0.2

0.1

0.5

0.1

0.1

0.1

0.1

0.1

3.5

8.8

0.7

2.9

0.5

0.11

0.5

0.1

0.5

0.1

0.2

0.1

0.2

0.1

9.6

14.5

1.5

7.1

1.4

0.29

1.4

0.2

1.6

0.4

1.0

0.2

0.9

0.2

3.4

10.0

0.8

3.5

0.6

0.06

0.5

0.1

0.5

0.1

0.2

0.1

0.3

0.1

5.7

14.3

1.2

5.1

0.9

0.14

0.8

0.1

0.8

0.2

0.4

0.1

0.4

0.1

7.0

16.5

1.5

6.4

1.2

0.22

1.0

0.2

1.0

0.2

0.6

0.1

0.6

0.1

4.2

10.1

0.8

3.6

0.7

0.06

0.6

0.1

0.6

0.1

0.3

0.1

0.3

0.1

3.2

9.0

0.6

2.9

0.5

0.04

0.4

0.1

0.4

0.1

0.2

0.1

0.2

0.1

11.3 4.2

AC

385 TZF390 TZF400 TZF410 TLM215 TLM200 TLM195 TLM190

T

ACCEPTED MANUSCRIPT

47

11.9

0.9

3.8

0.7

0.12

0.6

0.1

0.6

0.1

0.3

0.1

0.3

0.1

3.6

9.3

0.7

3.1

0.6

0.05

0.5

0.1

0.5

0.1

0.2

0.1

0.3

0.1

2.5

7.6

0.5

2.3

0.4

0.01

0.3

0.1

0.3

0.1

0.1

0.1

0.1

0.1

4.4

11.6

0.9

3.8

0.7

0.12

0.6

0.1

0.5

0.1

0.2

0.1

0.3

0.1

6.3

14.4

1.2

5.3

1.0

0.19

0.8

0.1

0.8

0.2

0.5

0.1

0.5

0.1

2.4

4.6

0.2

2.6

0.4

0.03

0.1

2.1

4.4

0.2

2.5

0.4

0.03

0.1

2.6

5.1

0.3

2.8

0.5

0.03

0.1

4.8

9.1

0.7

4.7

0.8

0.08

3.2

5.3

0.3

3.2

0.5

0.02

3.6

6.1

0.4

3.4

0.6

3.2

6.8

0.5

3.2

0.6

4.3

7.5

0.6

4.1

3.2

5.9

0.4

0.1

0.1

0.1

SC R

IP

4.2

0.3

0.1

0.1

0.1

0.2

0.1

0.1

0.2

0.1

0.1

0.1

0.1

0.1

0.1

0.3

0.1

0.1

0.1

0.2

0.1

NU

0.1

0.1

0.6

0.1

0.4

0.1

0.4

0.1

0.2

0.1

0.5

0.1

0.3

0.1

0.3

0.1

0.02

0.2

0.1

0.4

0.1

0.3

0.1

0.3

0.1

0.01

0.3

0.1

0.5

0.1

0.3

0.1

0.3

0.1

0.8

0.08

0.3

0.1

0.6

0.1

0.3

0.1

0.4

0.1

3.3

0.6

0.01

0.2

0.1

0.4

0.1

0.2

0.1

0.3

0.1

0.1

0.1

0.01

0.1

0.1

0.1

0.1

0.1

0.1

0.1

0.1

CE P

TE

D

MA

0.2

AC

180 TVP175 TVP170 TVP165 TVP160 TVP155 TVP150 TVP140 TVP135 TVP130 TVP125 TVP120 TVP115 TVP110 TVP105 LOD

T

ACCEPTED MANUSCRIPT

48

ACCEPTED MANUSCRIPT Table 4: Trace-element concentrations (mg/Kg) in all the samples

49

Cs 0.41 0.43 0.18 0.31 0.14 0.15 4.76 0.87 0.54 0.47 0.21 0.69 0.61 0.35 0.46 1.40 0.52 0.29 0.30 0.88 0.20 0.15 0.23 0.23 0.33 0.21 0.25 0.25 0.25 0.44 0.38 0.20 0.43 0.55 0.56 0.44 0.73 0.74 0.31 0.80 0.83 0.74 0.75 0.30 1.62 0.91 0.98 1.26 0.91 0.89 0.60 0.18 0.09 0.28 0.45

T

Y 3.1 4.4 2.1 4.0 1.1 1.5 7.0 24.2 5.6 7.9 2.4 7.6 11.6 7.0 7.3 15.9 5.2 2.6 3.1 9.4 2.1 2.2 3.1 11.0 4.0 1.8 4.1 2.8 3.6 6.2 9.8 2.6 4.1 7.2 4.7 6.8 3.3 3.4 2.2 4.0 2.8 3.5 3.6 1.7 47.0 3.6 7.5 14.6 6.0 6.7 4.8 3.7 20.2 3.6 5.7

IP

Sr 210 234 158 155 55 102 108 612 605 474 219 283 480 626 256 342 262 179 322 391 93 73 134 263 162 78 124 134 100 125 298 74 250 362 191 260 113 65 78 122 73 144 110 73 581 100 303 274 256 277 72 287 518 142 150

SC R

Rb 7.8 7.0 2.8 4.3 2.4 2.7 95.3 18.2 10.6 7.8 2.7 13.0 14.0 5.4 8.0 30.9 10.8 6.1 4.9 18.9 2.8 1.9 4.3 3.8 7.4 2.9 3.8 4.9 5.6 9.8 7.7 3.1 3.7 8.0 5.2 5.2 2.3 2.4 4.8 2.7 2.8 2.4 2.6 3.8 24.2 4.2 12.9 19.7 5.2 4.4 1.7 4.1 3.3 1.2 5.8

NU

Ni 19.4 22.2 22.1 30.5 14.8 16.4 27.8 39.3 23.6 29.7 10.4 35.3 39.2 16.7 18.7 58.4 26.3 12.2 15.4 39.7 12.6 15.2 15.2 11.4 23.6 19.0 20.9 15.2 20.1 15.6 28.7 15.2 25.7 30.3 18.7 20.2 17.9 19.5 20.5 24.2 19.8 19.8 19.4 11.6 41.5 20.1 18.9 29.1 27.3 22.8 10.7 4.9 1.2 11.2 25.2

MA

Co 19.0 18.5 36.4 17.3 51.2 24.4 12.1 6.7 15.8 6.5 19.8 4.4 7.4 21.5 11.9 3.2 18.9 15.7 16.9 12.7 13.6 23.3 34.2 12.3 31.7 35.3 34.2 23.6 34.9 21.0 12.7 33.3 29.8 15.2 59.2 25.4 46.6 54.6 51.1 35.5 50.6 61.3 79.8 65.6 15.3 51.4 29.9 52.1 29.4 46.9 89.0 54.7 20.6 73.4 12.3

D

Cr 34.6 55.5 33.2 33.5 22.3 20.4 80.3 55.8 29.8 30.3 34.8 51.1 49.8 28.4 23.7 82.1 26.9 13.8 18.2 54.2 7.2 25.8 11.7 17.0 27.5 17.5 25.6 17.8 10.3 16.7 25.8 25.5 25.3 41.1 37.1 21.0 31.6 29.7 38.4 46.0 51.4 32.8 43.0 25.1 118.5 45.2 49.7 60.2 61.0 45.7 27.7 32.6 32.2 31.7 49.5

TE

V 203 75 94 145 109 98 430 180 100 175 43 209 215 71 62 321 137 35 54 121 29 57 48 41 73 56 31 56 41 28 106 36 161 212 120 136 110 70 94 95 166 84 86 64 407 109 146 223 140 108 34 35 33 181 90

CE P

Sc --------------------------------1.6 2.8 2.2 3.0 1.4 1.6 0.8 1.6 2.0 1.9 1.5 0.5 6.6 2.1 3.1 3.3 1.7 1.6 1.7 0.8 0.6 4.7 5.1

AC

TZF-070 TZF-080 TZF-100 TZF-114 TZF-125 TZF-130 TZF-160 TZF-170 TZF-200 TZF-205 TZF-215 TZF-220 TZF-225 TZF-235 TZF-245 TZF-255 TZF-260 TZF-280 TZF-290 TZF-300 TZF-310 TZF-320 TZF-330 TZF-340 TZF-350 TZF-360 TZF-370 TZF-375 TZF-385 TZF-390 TZF-400 TZF-410 TLM-215 TLM-200 TLM-195 TLM-190 TLM-185 TLM-175 TLM-170 TLM-165 TLM-160 TLM-155 TLM-150 TLM-145 TLM-140 TLM-130 TLM-125 TLM-122 TLM-115 TLM-110 TLM-063 TLM-050 TLM-033 TVP-210 TVP-205

Mn 20 30 11 19 16 9 36 58 31 26 26 27 22 21 61 30 30 21 22 12 15 7 16 35 19 17 24 17 22 24 29 9 17 18 23 15 9 19 8 11 18 20 23 6 24 25 40 25 28 24 20 12 10 8 21

Ba 447 514 240 216 168 234 380 343 351 486 287 359 456 624 385 305 297 146 202 293 205 160 306 205 419 379 300 253 368 382 297 271 449 210 1282 454 297 269 507 462 252 331 362 148 287 411 1458 412 409 352 301 336 271 164 207

Th 0.5 0.3 0.1 0.2 0.2 0.2 12.3 1.0 0.5 0.4 0.2 0.6 5.5 0.3 0.3 1.3 0.7 0.2 0.2 0.7 0.2 0.2 0.2 0.3 0.3 0.2 0.5 0.4 0.2 0.4 0.4 1.2 1.2 2.0 1.3 1.5 0.5 0.5 1.5 0.6 0.6 0.5 0.6 1.3 6.6 0.8 2.3 4.8 1.2 0.9 0.4 1.4 1.8 1.6 2.5

U 2.6 3.9 4.0 5.4 4.5 2.7 4.3 11.4 3.1 5.1 1.4 5.0 5.6 2.4 2.6 7.6 2.7 1.8 2.0 7.7 1.3 2.4 1.8 6.5 2.5 2.0 3.2 5.0 7.2 2.4 4.5 2.2 1.6 2.8 2.4 2.5 2.1 3.2 1.8 3.3 1.8 2.5 3.4 1.6 11.6 1.8 4.7 6.5 5.2 2.2 1.7 1.5 7.7 2.6 3.8

ACCEPTED MANUSCRIPT Ni 29.6 16.4 16.9 21.5 17.7 8.8 18.2 25.7 15.7 21.2 19.7 16.5 20.6 30.4 22.5 25.1 12.3 0.1

Rb 7.1 1.4 0.1 1.7 0.3 0.1 2.7 3.8 2.1 2.5 2.3 6.6 1.7 3.8 3.1 4.5 2.8 0.1

D TE CE P 50

Sr 225 62 55 119 139 48 159 226 74 60 60 136 95 86 194 62 41 1

Y 7.5 4.9 2.6 3.9 4.0 2.2 3.6 7.7 1.7 1.0 1.6 4.6 4.7 3.4 3.7 4.0 2.7 0.1

Cs 0.61 0.23 0.25 0.28 0.26 0.08 0.37 0.35 0.26 0.29 0.24 0.36 0.27 0.33 0.20 0.53 0.30 0.01

T

Co 10.4 25.5 37.3 23.6 41.6 44.3 30.6 21.9 31.3 48.9 33.5 26.2 83.8 49.0 49.8 95.0 97.2 0.1

IP

Cr 61.0 35.3 29.0 34.0 35.9 21.2 36.2 54.1 31.1 31.6 30.4 39.7 22.7 39.4 32.8 45.9 25.6 0.1

SC R

V 112 42 29 71 80 22 64 82 88 15 26 147 21 77 103 62 28 1

NU

Sc 10.2 8.8 7.1 7.3 7.6 7.5 7.2 6.6 7.1 6.5 6.4 6.8 6.7 7.2 7.1 6.9 6.4 0.1

MA

Mn 12 15 9 25 13 12 23 21 12 17 16 13 17 21 18 15 8 1

AC

TVP-195 TVP-185 TVP-180 TVP-175 TVP-170 TVP-165 TVP-160 TVP-155 TVP-150 TVP-140 TVP-135 TVP-130 TVP-125 TVP-120 TVP-115 TVP-110 TVP-105 LOD

Ba 289 157 180 271 185 169 268 300 197 214 211 285 207 235 166 285 228 1

Th 2.9 1.6 1.5 2.1 1.6 1.3 2.2 2.2 1.0 1.0 1.1 1.5 1.0 1.3 1.3 1.7 1.3 0.1

U 6.0 2.7 1.5 2.5 3.5 1.2 2.5 4.2 2.8 1.4 3.4 3.4 4.1 2.8 3.3 3.4 2.2 0.1

ACCEPTED MANUSCRIPT Table 5: Enrichment factors (EF) of REE and trace elements in cherts from the three stratigraphic sections under study U, V, Sr

V, Co, Sr, U

10 > EF > 1

REE, Cr, Ni, Cs, Co, Rb, Ba, Y, Th

REE, Cr, Ni, Cs, Rb, Sr, Ba, Y, Sc

EF < 1

Mn

Mn

T

EF > 10

Delicias-Villa Páez La, Dy, Co, Ba, Th, U Nd, Sm, Y, Er, V, Lu, Yb, Cr, Ni, Rb, Sr, Gd, Sc Mn, Cs, Ce, Pr, Nd, Eu, Tb, Ho, Er, Tm

IP

La Molina Mine

AC

CE P

TE

D

MA

NU

SC R

Zorca River

51

sampled

ACCEPTED MANUSCRIPT Table 6: Correlation coefficients (R) between Al2O3 or Co and or trace elements studied for the three sampling sites Delicias-Villa Zorca River La Molina Mine Páez Co -0.04 -0.27 -0.16 -0.31 -0.20 -0.23 -0.25 -0.15 -0.23 -0.39 -0.24 -0.33 -0.39 -0.39 -0.35 -0.35 -0.35 -0.32 -0.36 -0.32 -0.31 -0.28 -0.29 -0.28 -0.26 0.00

AC

CE P

TE

D

MA

NU

SC R

IP

T

Al2O3 Co Al2O3 Co Al2O3 Mn 0.49 -0.38 Mn 0.13 0.07 Mn 0.36 Sr 0.17 -0.58 Sr 0.11 -0.20 Sr -0.02 V 0.57 -0.37 V 0.53 -0.21 V -0.08 Cr 0.77 -0.52 Cr 0.61 -0.41 Cr 0.35 Ni 0.64 -0.46 Ni 0.69 -0.42 Ni 0.19 Rb 0.92 -0.46 Rb 0.89 -0.48 Rb 0.95 Y 0.27 -0.41 Y 0.01 -0.06 Y 0.09 Cs 0.92 -0.45 Cs 0.57 -0.13 Cs 0.93 Ba 0.15 -0.11 Ba 0.04 0.03 Ba 0.72 Th 0.66 -0.38 Th 0.64 -0.41 Th 0.82 U 0.29 -0.23 U 0.05 -0.15 U -0.01 La 0.53 -0.48 La 0.16 -0.15 La 0.44 Ce 0.61 -0.48 Ce 0.41 -0.25 Ce 0.57 Pr 0.58 -0.47 Pr 0.29 -0.20 Pr 0.53 Nd 0.54 -0.46 Nd 0.29 -0.21 Nd 0.55 Sm 0.50 -0.46 Sm 0.28 -0.19 Sm 0.51 Eu 0.41 -0.43 Eu 0.24 -0.16 Eu 0.51 Tb 0.32 -0.39 Tb 0.21 -0.18 Tb 0.38 Gd 0.38 -0.43 Gd 0.19 -0.16 Gd 0.38 Dy 0.37 -0.43 Dy 0.14 -0.13 Dy 0.30 Ho 0.33 -0.42 Ho 0.11 -0.13 Ho 0.20 Er 0.35 -0.42 Er 0.12 -0.12 Er 0.20 Tm 0.23 -0.34 Tm 0.13 -0.14 Tm 0.16 Yb 0.34 -0.44 Yb 0.13 -0.13 Yb 0.19 Lu 0.28 -0.34 Lu 0.12 -0.13 Lu 0.17 Sc --Sc 0.68 -0.31 Sc 0.05 Note: RAl-Co negative values of 0.51, 0.56 and 0.27, respectively, for Zorca River, La Molina Mine and Delicias-Villa Páez sections.

52

REE

ACCEPTED MANUSCRIPT Highlights

AC

CE P

TE

D

MA

NU

SC R

IP

T

Most of the Táchira cherts occurred near or within the continental margin field A hemipelagic subfield relative to the discrimination diagram has been established The Guayana Massif was the source supplying detrital material to sampled cherts

53

ACCEPTED MANUSCRIPT Appendix A-1: TOC, sulfur, major and minor element contents in chert samples from the three sections studied.

TLM-165 TLM-160 TLM-155 TLM-150 TLM-145 TLM-140 TLM-130 TLM-125 TLM-122 TLM-115 TLM-110 TLM-063 TLM-050 TLM-033 TVP-210 TVP-205 TVP-195 TVP-185

54

P 2O 5 0.105 0.060 0.080 0.176 0.034 0.044 0.050 2.051 0.862 0.779 0.151 0.261 0.477 0.614 0.527 0.646 0.124 0.137 0.289 0.995 0.039 0.126 0.172 1.047 0.119 0.105 0.243 0.112 0.135 0.188 0.582 0.156 0.074 0.235 0.049 0.187 0.040 0.059 0.034 P 2O 5 0.060 0.020 0.050 0.085 0.034 3.522 0.028 0.173 0.324 0.233 0.341 0.399 0.243 2.709 0.063 0.205 0.275 0.285

T

K2O 0.18 0.16 0.10 0.11 0.080 0.08 0.176 0.08 0.034 2.05 0.044 0.41 0.050 0.25 2.051 0.19 0.862 0.08 0.779 0.30 0.151 0.30 0.261 0.16 0.477 0.20 0.614 0.65 0.527 0.23 0.646 0.16 0.124 0.12 0.137 0.42 0.289 0.07 0.995 0.06 0.039 0.12 0.126 0.12 0.172 0.18 1.047 0.07 0.119 0.08 0.105 0.11 0.13 0.112 0.22 0.135 0.16 0.188 0.08 0.582 0.156 0.08 0.26 0.11 0.14 0.03 0.03 0.03 K2O 0.05 0.05 0.05 0.05 0.050 0.02 0.085 0.66 0.034 0.07 3.522 0.22 0.028 0.33 0.173 0.11 0.324 0.08 0.233 0.02 0.341 0.04 0.03 0.243 2.709 0.06 0.15 0.16 0.04

IP

Na2O 0.15 0.18 0.09 0.12 0.09 0.08 0.23 0.27 0.11 0.12 0.08 0.12 0.12 0.09 0.12 0.16 0.22 0.614 0.12 0.65 0.11 0.23 0.646 0.11 0.16 0.124 0.13 0.12 0.137 0.12 0.42 0.289 0.09 0.07 0.995 0.09 0.06 0.039 0.09 0.12 0.126 0.09 0.12 0.172 0.11 0.18 1.047 0.09 0.07 0.119 0.09 0.08 0.105 0.09 0.11 0.243 0.08 0.13 0.112 0.09 0.22 0.135 0.11 0.16 0.188 0.08 0.582 0.11 0.36 0.156 0.10 0.21 0.06 0.06 0.11 Na2O 0.07 0.06 0.06 0.07 0.05 0.09 0.05 0.050 0.34 0.02 0.085 0.08 0.66 0.034 0.19 0.07 3.522 0.25 0.22 0.028 0.10 0.33 0.173 0.07 0.11 0.324 0.05 0.08 0.233 0.09 0.399 0.341 0.10 0.04 0.03 0.243 0.13 0.16 2.709 0.15 0.13

SC R

MgO 0.22 0.20 0.08 0.15 0.09 0.02 0.12 0.03 0.09 0.58 0.08 0.17 0.23 0.17 0.27 0.20 0.11 0.12 0.13 0.08 0.18 0.12 0.61 0.12 0.18 0.30 0.12 0.13 0.22 0.20 0.09 0.12 0.65 0.527 0.16 0.13 0.11 0.23 0.646 0.614 0.18 0.11 0.16 0.124 0.05 0.13 0.12 0.137 0.03 0.12 0.42 0.289 0.05 0.09 0.07 0.995 0.13 0.09 0.06 0.039 0.08 0.09 0.12 0.126 0.03 0.09 0.12 0.172 0.08 0.11 0.18 1.047 0.05 0.07 0.119 0.10 0.09 0.105 0.10 0.09 0.11 0.13 0.08 0.112 0.03 0.09 0.22 0.135 0.11 0.16 0.188 0.12 0.23 0.08 0.582 0.11 0.156 0.16 0.07 0.09 0.05 MgO 0.10 0.10 0.10 0.09 0.06 0.02 0.07 0.05 0.41 0.09 0.05 0.050 0.11 0.34 0.02 0.085 0.20 0.08 0.66 0.034 0.23 0.19 0.07 3.522 0.16 0.22 0.028 0.15 0.10 0.173 0.10 0.07 0.11 0.07 0.02 0.08 0.233 0.22 0.09 0.399 0.341 0.10 0.04 0.11 0.12 0.03 0.243 0.12 2.709 0.06

NU

CaO 5.50 7.18 3.30 3.99 1.60 3.17 0.44 16.79 14.92 12.42 5.90 8.93 14.50 15.55 7.74 11.77 0.527 8.13 0.30 5.18 0.12 0.22 9.68 0.11 0.23 0.65 13.97 0.13 0.16 0.124 0.646 3.30 0.18 0.11 0.137 2.12 0.05 0.13 0.12 5.04 0.03 0.12 0.42 0.289 8.10 0.05 0.09 0.07 0.995 6.04 0.13 0.09 0.06 0.039 2.49 0.08 0.09 0.12 0.126 4.30 0.03 0.09 0.12 0.172 4.69 0.08 0.11 0.18 1.047 2.58 0.09 0.07 0.119 3.76 0.10 0.08 0.105 13.61 0.10 0.09 0.243 2.56 0.13 0.08 0.03 0.09 0.22 0.135 7.66 12.41 0.11 0.16 0.188 2.99 0.08 0.582 7.16 0.156 0.92 0.32 0.30 CaO 2.03 0.52 2.07 1.30 0.10 1.52 0.09 0.06 11.38 0.02 0.07 0.05 1.58 0.41 0.09 0.05 0.050 11.17 0.11 0.34 0.02 0.085 9.11 0.20 0.08 0.66 0.034 10.58 0.23 0.19 0.07 3.522 9.03 0.16 0.25 0.22 0.028 0.64 0.15 0.10 0.33 0.173 13.13 0.10 0.07 0.11 0.324 18.73 0.07 0.05 0.08 0.233 0.22 0.09 0.02 0.341 6.28 7.05 0.10 0.04 0.399 10.83 0.03 0.243 1.07 2.709

MA

D

Fe2O3 0.30 0.31 0.13 0.23 0.14 0.13 1.82 0.51 0.34 16.79 0.27 14.92 0.14 12.42 0.40 0.41 8.93 0.24 14.50 0.26 0.92 7.74 0.30 11.77 0.18 0.19 8.13 0.30 0.12 0.21 5.18 0.13 0.22 0.20 0.53 9.68 0.12 0.65 0.527 0.13 13.97 0.11 0.23 0.646 0.13 3.30 0.18 0.11 0.16 0.124 0.17 2.12 0.05 0.13 0.12 0.137 0.19 5.04 0.03 0.12 0.42 0.289 0.27 8.10 0.05 0.09 0.07 0.995 0.16 6.04 0.13 0.09 0.06 0.039 0.19 2.49 0.08 0.09 0.12 0.126 0.17 4.30 0.03 0.09 0.12 0.172 0.17 4.69 0.08 0.11 0.18 1.047 0.31 2.58 0.05 0.09 0.07 0.119 0.34 3.76 0.10 0.09 0.08 0.105 0.14 13.61 0.10 0.09 0.11 0.243 2.56 0.13 0.08 0.112 0.27 0.65 0.03 0.09 0.22 0.135 0.19 0.11 0.16 0.188 0.34 0.08 0.582 0.09 0.156 0.10 0.16 Fe2O3 0.13 0.18 0.13 0.14 2.07 0.12 1.30 0.10 1.26 1.52 0.09 0.06 0.21 11.38 0.02 0.07 0.05 0.49 1.58 0.41 0.09 0.05 0.050 0.77 11.17 0.11 0.34 0.02 0.085 0.27 9.11 0.20 0.08 0.66 0.034 0.18 10.58 0.23 0.19 0.07 3.522 0.09 9.03 0.16 0.25 0.22 0.028 0.14 0.64 0.15 0.10 0.33 0.173 0.12 13.13 0.10 0.07 0.11 0.324 18.73 0.07 0.05 0.08 0.233 0.16 0.43 0.22 0.09 0.02 0.341 0.35 0.10 0.04 0.399 0.19 0.03 0.243 2.709

TE

TiO2 0.03 0.03 0.02 0.03 0.02 0.02 0.42 0.05 0.05 0.03 0.02 0.05 0.07 0.03 0.03 0.12 0.26 0.05 0.92 7.74 0.03 0.30 11.77 0.18 0.02 0.19 8.13 0.30 0.12 0.07 0.21 5.18 0.13 0.22 0.20 0.02 0.53 9.68 0.12 0.65 0.527 0.02 0.13 13.97 0.11 0.23 0.646 0.02 0.13 3.30 0.18 0.11 0.16 0.124 0.02 0.17 2.12 0.05 0.13 0.12 0.137 0.03 0.19 5.04 0.12 0.42 0.289 0.02 0.27 8.10 0.05 0.09 0.07 0.995 0.02 6.04 0.13 0.09 0.06 0.039 0.03 0.19 0.08 0.09 0.12 0.126 0.03 0.17 4.30 0.09 0.12 0.172 0.05 0.17 4.69 0.08 0.18 1.047 0.05 0.31 2.58 0.09 0.119 0.03 0.34 3.76 0.10 0.09 0.08 0.14 13.61 0.10 0.09 0.11 0.243 0.04 2.56 0.13 0.08 0.112 0.03 0.09 0.22 0.135 0.05 0.11 0.16 0.188 0.02 0.08 0.582 0.01 0.156 0.01 TiO2 0.02 0.02 0.02 0.02 0.13 0.01 0.14 2.07 0.18 0.12 1.30 0.10 0.03 1.26 1.52 0.09 0.06 0.06 0.21 11.38 0.02 0.07 0.05 0.09 0.49 1.58 0.41 0.05 0.050 0.04 0.77 11.17 0.11 0.34 0.02 0.085 0.02 0.27 9.11 0.20 0.08 0.66 0.034 0.01 0.18 10.58 0.23 0.19 0.07 3.522 0.01 0.09 9.03 0.16 0.25 0.22 0.028 0.01 0.14 0.64 0.15 0.10 0.33 0.173 0.12 13.13 0.10 0.07 0.11 0.324 0.02 0.04 18.73 0.07 0.05 0.08 0.233 0.04 0.22 0.09 0.02 0.341 0.02 0.10 0.04 0.399 0.03 0.243 2.709

CE P

Al2O3 1.70 1.61 0.89 1.30 0.02 0.60 0.03 0.59 0.02 9.03 0.02 2.44 0.42 2.21 0.05 1.38 0.05 0.60 0.03 2.25 0.02 1.95 0.05 1.04 0.07 1.55 4.46 0.03 1.66 0.12 0.26 1.11 0.05 0.92 7.74 1.08 0.03 0.30 11.77 0.18 2.42 0.02 0.19 8.13 0.30 0.12 0.62 0.07 0.21 5.18 0.13 0.22 0.20 0.68 0.02 0.53 9.68 0.12 0.65 0.527 0.79 0.02 0.13 13.97 0.11 0.23 0.646 0.66 0.02 0.13 3.30 0.18 0.11 0.16 0.124 1.19 0.02 0.17 2.12 0.05 0.13 0.12 0.137 0.79 0.03 0.19 5.04 0.12 0.42 0.289 0.91 0.02 0.27 8.10 0.05 0.09 0.07 0.995 0.87 0.02 0.16 6.04 0.13 0.09 0.06 0.039 1.25 0.03 0.19 2.49 0.08 0.09 0.12 0.126 2.02 0.03 0.17 4.30 0.09 0.12 0.172 1.42 0.05 0.17 4.69 0.08 0.11 0.18 1.047 0.83 0.05 0.31 2.58 0.09 0.07 0.119 0.03 0.34 3.76 0.10 0.09 0.08 0.105 0.68 3.06 0.14 13.61 0.10 0.09 0.11 0.243 0.76 2.56 0.13 0.08 0.112 1.70 0.03 0.09 0.22 0.135 0.05 0.11 0.16 0.188 0.00 0.08 0.582 0.29 0.156 Al2O3 0.16 0.00 0.03 0.01 0.02 0.08 0.02 0.13 6.03 0.01 0.14 2.07 0.28 0.18 0.12 1.30 0.10 1.77 0.03 1.26 1.52 0.09 0.06 3.58 0.06 0.21 11.38 0.02 0.07 0.05 0.74 0.09 0.49 1.58 0.41 0.05 0.050 0.58 0.04 0.77 11.17 0.11 0.34 0.02 0.085 0.00 0.02 0.27 9.11 0.20 0.08 0.66 0.034 0.35 0.01 0.18 10.58 0.23 0.19 0.07 3.522 0.31 0.01 0.09 9.03 0.16 0.25 0.22 0.028 0.01 0.14 0.64 0.15 0.10 0.33 0.173 0.63 1.25 0.12 13.13 0.10 0.07 0.11 0.324 1.45 18.73 0.07 0.05 0.08 0.233 0.40 0.22 0.09 0.02 0.341 0.10 0.04 0.399 0.03 0.243 2.709

AC

TZF-070 TZF-080 TZF-100 TZF-114 TZF-125 TZF-130 TZF-160 TZF-170 TZF-200 TZF-205 TZF-215 TZF-220 TZF-225 TZF-235 TZF-245 TZF-255 TZF-260 TZF-280 TZF-290 TZF-300 TZF-310 TZF-320 TZF-330 TZF-340 TZF-350 TZF-360 TZF-370 TZF-375 TZF-385 TZF-390 TZF-400 TZF-410 TLM-215 TLM-200 TLM-195 TLM-190 TLM-185 TLM-175 TLM-170

SiO2 87.49 84.51 92.66 90.77 96.08 93.32 84.55 66.01 70.13 75.45 88.36 80.63 70.91 70.00 83.73 72.08 82.78 4.46 88.96 1.66 0.12 80.95 1.11 0.05 0.92 71.22 1.08 0.03 0.30 11.77 93.00 2.42 0.02 0.19 8.13 0.30 95.11 0.62 0.07 0.21 5.18 0.13 0.22 89.65 0.68 0.02 0.53 9.68 0.12 0.65 84.29 0.79 0.02 0.13 13.97 0.11 0.23 0.646 87.19 0.66 0.02 0.13 3.30 0.18 0.11 0.16 0.124 94.24 1.19 0.02 0.17 2.12 0.05 0.13 0.12 0.137 90.83 0.02 0.03 0.19 5.04 0.12 0.42 0.289 90.18 0.91 0.16 0.27 8.10 0.05 0.09 0.07 0.995 93.49 0.87 0.02 2.49 6.04 0.13 0.09 0.06 0.039 90.39 1.25 0.03 0.19 0.08 0.09 0.12 0.126 73.33 2.02 0.03 0.17 4.30 0.11 0.09 0.12 0.172 94.08 1.42 0.05 0.17 4.69 0.08 0.07 0.18 1.047 0.83 0.05 0.31 2.58 0.09 0.105 85.88 0.119 77.76 0.03 0.34 3.76 0.10 0.09 0.08 80.88 0.14 13.61 0.10 0.09 0.11 0.243 86.43 2.56 0.13 0.08 0.112 95.01 0.03 0.09 0.22 0.135 89.58 0.11 0.16 0.188 96.71 0.08 0.582 SiO2 0.156 94.20 93.89 86.72 87.41 0.03 98.79 0.01 0.02 76.32 0.08 0.02 0.13 85.74 6.03 0.01 0.14 2.07 75.25 0.28 0.18 0.12 1.30 0.10 78.64 1.77 0.03 1.26 1.52 0.09 0.06 81.92 3.58 0.06 0.21 11.38 0.02 0.07 0.05 80.01 0.74 0.09 0.49 1.58 0.41 0.05 0.050 87.75 0.58 0.04 0.77 11.17 0.11 0.34 0.02 0.085 80.52 0.00 0.02 0.27 9.11 0.20 0.08 0.66 0.034 73.64 0.35 0.01 0.18 10.58 0.23 0.19 0.07 3.522 0.31 0.01 0.09 9.03 0.16 0.25 91.28 0.22 0.028 88.03 0.01 0.14 0.64 0.15 0.10 0.33 0.173 83.12 0.12 13.13 0.10 0.07 0.11 0.324 96.80 18.73 0.07 0.05 0.08 0.233 0.22 0.09 0.02 0.341 0.10 0.04 0.399 0.03 0.243 2.709

S 0.12 0.20 0.14 0.16 0.11 0.10 0.54 0.24 0.14 0.20 0.07 0.18 0.21 0.08 0.12 0.28 0.22 0.09 0.11 0.13 0.10 0.10 0.12 0.07 0.17 0.14 0.15 0.13 0.14 0.15 0.21 0.12 -------S -------------------

TOC 1.26 C 0.87 0.81 0.98 1.02 0.90 2.98 1.90 1.32 1.76 0.46 1.63 1.75 0.63 1.18 2.62 1.05 0.77 1.03 1.23 1.02 0.38 1.13 0.46 1.56 1.32 1.35 0.61 0.68 0.88 1.82 0.33 -------TOC -C ------------------

Si0 0.92 0.90 0.96 0.94 0.97 0.96 0.88 0.77 0.80 0.84 0.93 0.87 0.81 0.81 0.90 0.81 0.89 0.93 0.88 0.81 0.96 0.97 0.94 0.90 0.92 0.96 0.94 0.94 0.96 0.94 0.83 0.96 0.91 0.83 0.95 0.90 0.99 0.99 0.99 Si0 0.98 0.99 0.97 0.98 0.98 0.80 0.98 0.85 0.85 0.87 0.89 0.99 0.86 0.79 0.93 0.91 0.87 0.98

ACCEPTED MANUSCRIPT 0.24 0.01 0.18 1.46 0.04 0.13 0.03 0.062 --0.98 0.85 0.03 0.28 5.62 0.57 0.16 0.10 0.171 --0.93 0.36 0.01 0.16 6.47 0.05 0.12 0.04 0.227 --0.93 0.19 0.01 0.10 0.66 0.05 0.12 0.02 0.108 --0.99 0.95 0.03 0.26 10.05 1.32 0.16 0.09 0.247 --0.88 0.95 0.03 0.22 12.22 0.45 0.15 0.11 0.624 --0.86 0.15 0.01 0.10 3.12 0.02 0.09 0.02 0.085 --0.96 0.30 0.01 0.14 1.92 0.08 0.10 0.03 0.027 --0.98 0.21 0.01 0.12 2.01 0.24 0.10 0.03 0.063 --0.98 1.00 0.03 0.19 5.03 0.07 0.11 0.09 0.191 --0.93 0.13 0.01 0.09 2.77 0.04 0.11 0.02 0.413 --0.97 0.40 0.02 0.13 3.30 0.04 0.10 0.04 0.070 --0.96 0.30 0.01 0.13 9.90 0.06 0.11 0.03 0.123 --0.89 0.64 0.02 0.17 1.08 0.04 0.10 0.05 0.130 --0.98 0.27 0.02 0.13 0.00 0.01 0.08 0.03 0.149 --0.99 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.001 0.01 0.05 -1.21 1.41 0.97 0.76 1.20 0.47 1.69 1.711 1.19 0.68 -0 Notes: LOD (limit of detection), RSD (relative standard deviation) and Si =Si/(Si+Al+Ca+Fe).

SC R

IP

T

96.53 91.39 90.57 94.99 82.02 80.83 94.67 93.96 91.85 87.36 93.23 93.09 87.02 91.38 98.77 0.01 0.09

NU

TVP-180 TVP-175 TVP-170 TVP-165 TVP-160 TVP-155 TVP-150 TVP-140 TVP-135 TVP-130 TVP-125 TVP-120 TVP-115 TVP-110 TVP-105 LOD RSD

Appendix A-2: Rare earth element concentrations (mg/Kg) in all the chert samples. Ce

Pr

Nd

Sm

4.9

8.3

1.0

3.4

0.7

5.2

8.8

1.1

3.4

0.7

2.0

2.9

0.4

1.2

3.4

4.7

0.6

1.6

2.4

1.9

2.9

35.7

65.5

18.8

26.5

5.6

Eu

Gd

MA

La

Tb

Dy

Ho

Er

Tm

Yb

Lu

0.6

0.1

0.5

0.1

0.3

0.1

0.1

0.1

0.14

0.7

0.1

0.6

0.1

0.4

0.1

0.1

0.1

0.2

0.03

0.2

0.1

0.2

0.1

0.1

0.1

0.1

0.1

2.1

0.4

0.08

0.4

0.1

0.4

0.1

0.3

0.1

0.1

0.1

0.3

0.9

0.2

0.03

0.1

0.5

0.1

0.1

0.1

0.1

0.1

0.1

0.3

1.1

0.2

0.03

0.2

0.1

0.2

0.1

0.1

0.1

0.1

0.1

8.3

25.7

3.8

0.37

1.2

0.2

1.2

0.3

0.9

0.2

1.0

0.1

3.7

13.1

2.5

0.51

2.6

0.4

2.5

0.6

1.6

0.2

1.2

0.2

CE P

TE

D

0.13

AC

TZF070 TZF080 TZF100 TZF114 TZF125 TZF130 TZF160 TZF170 TZF200 TZF205 TZF215 TZF220 TZF225 TZF235 TZF245 TZF255 TZF260 TZF280 TZF290

9.0

1.2

3.8

0.7

0.14

0.6

0.1

0.6

0.1

0.4

0.1

0.3

0.1

9.1

1.1

3.6

0.7

0.13

0.7

0.1

0.7

0.2

0.6

0.1

0.4

0.1

2.2

3.3

0.4

1.4

0.3

0.05

0.2

0.1

0.3

0.1

0.2

0.1

0.1

0.1

7.0

10.6

1.5

5.0

0.9

0.19

0.9

0.1

0.9

0.2

0.6

0.1

0.4

0.1

9.6

12.8

1.8

6.2

1.1

0.23

1.2

0.2

1.2

0.3

0.8

0.1

0.6

0.1

4.9

6.4

0.9

3.2

0.6

0.13

0.7

0.1

0.7

0.2

0.5

0.1

0.2

0.1

6.7

10.3

1.3

4.4

0.8

0.16

0.8

0.1

0.8

0.2

0.5

0.1

0.3

0.1

16.0

24.9

3.2

10.5

1.9

0.35

1.7

0.3

1.7

0.4

1.1

0.2

0.9

0.1

5.8

10.3

1.2

4.1

0.8

0.14

0.7

0.1

0.6

0.1

0.4

0.1

0.2

0.1

15.2

15.5

0.5

1.6

0.3

0.06

0.3

0.1

0.3

0.1

0.2

0.1

0.1

0.1

2.8

4.3

0.6

1.8

0.3

0.06

0.3

0.1

0.3

0.1

0.2

0.1

0.1

0.1

7.0

55

ACCEPTED MANUSCRIPT 2.0

6.4

1.1

0.22

1.1

0.2

1.0

0.2

0.7

0.1

0.6

0.1

2.0

3.5

0.4

1.4

0.3

0.05

0.2

0.1

0.3

0.1

0.2

0.1

0.1

0.1

1.8

2.7

0.3

1.2

0.2

0.03

0.2

0.1

0.2

0.1

0.2

0.1

0.1

0.1

3.0

4.9

0.6

1.9

0.4

0.07

0.3

0.1

0.3

0.1

0.2

0.1

0.1

0.1

7.2

10.6

1.3

4.7

0.9

0.18

1.0

0.1

1.0

0.2

0.7

0.1

0.5

0.1

3.7

6.5

0.8

2.7

0.5

0.09

0.5

0.1

0.5

0.1

0.3

0.1

0.1

0.1

2.0

3.4

0.4

1.4

0.3

0.05

0.2

3.0

4.7

0.6

2.2

0.4

0.09

0.4

2.9

5.0

0.6

2.0

0.4

0.07

0.3

4.0

7.2

0.9

2.8

0.5

0.10

6.4

11.5

1.5

4.9

0.9

0.18

7.3

11.9

1.5

5.1

1.0

2.5

4.1

0.5

1.6

0.3

5.5

9.4

1.1

5.2

1.0

7.3

11.8

1.4

6.6

3.9

7.3

0.7

2.7

6.2

10.6

La

Ce

2.2

4.4

2.0

SC R

IP

T

15.1

0.2

0.1

0.2

0.1

0.1

0.1

0.1

0.4

0.1

0.3

0.1

0.1

0.1

0.1

0.3

0.1

0.2

0.1

0.1

0.1

0.4

0.1

0.4

0.1

0.3

0.1

0.1

0.1

0.8

0.1

0.8

0.2

0.5

0.1

0.3

0.1

0.18

0.9

0.1

1.0

0.2

0.7

0.1

0.6

0.1

0.06

0.3

0.1

0.3

0.1

0.2

0.1

0.1

0.1

0.41

0.8

0.2

0.8

0.1

0.2

0.1

0.2

0.1

1.4

0.38

1.1

0.2

1.1

0.2

0.4

0.1

0.4

0.1

0.6

0.46

0.4

0.1

0.7

0.1

0.2

0.1

0.2

0.1

D

MA

NU

0.1

TE

CE P

TLM185 TLM175 TLM170 TLM165 TLM160 TLM155 TLM150 TLM145 TLM140 TLM130 TLM125 TLM122

9.2

1.3

6.2

1.4

0.46

1.2

0.2

1.2

0.2

0.4

0.1

0.4

0.1

Pr

Nd

Sm

Eu

Gd

Tb

Dy

Ho

Er

Tm

Yb

Lu

0.3

1.3

0.3

0.12

0.1

0.1

0.4

0.1

0.1

0.1

0.1

0.1

AC

TZF300 TZF310 TZF320 TZF330 TZF340 TZF350 TZF360 TZF370 TZF375 TZF385 TZF390 TZF400 TZF410 TLM215 TLM200 TLM195 TLM190

4.0

0.3

1.1

0.3

0.10

0.1

0.1

0.4

0.1

0.1

0.1

0.1

0.1

8.2

0.6

2.5

0.5

0.15

0.4

0.1

0.3

0.1

0.1

0.1

0.1

0.1

2.6

4.8

0.4

1.6

0.3

0.17

0.2

0.1

0.5

0.1

0.1

0.1

0.1

0.1

2.3

4.4

0.3

1.2

0.2

0.10

0.1

0.1

0.4

0.1

0.1

0.1

0.1

0.1

2.2

4.4

0.3

1.3

0.3

0.13

0.2

0.1

0.4

0.1

0.1

0.1

0.1

0.1

2.4

4.6

0.3

1.4

0.3

0.14

0.2

0.1

0.4

0.1

0.1

0.1

0.1

0.1

2.4

7.5

0.5

2.2

0.4

0.03

0.3

0.1

0.3

0.1

0.1

0.1

0.1

0.1

33.9

69.2

7.0

30.3

6.1

0.98

5.1

0.8

4.5

0.9

3.1

0.5

2.5

0.4

3.0

5.8

0.5

1.9

0.4

0.17

0.2

0.1

0.5

0.1

0.1

0.1

0.1

0.1

7.6

11.9

1.6

6.9

1.4

0.62

1.0

0.2

1.1

0.2

0.6

0.1

0.6

0.1

11.3

26.4

2.5

12.9

3.3

0.87

2.7

0.5

2.7

0.5

1.3

0.2

1.0

0.1

3.1

56

ACCEPTED MANUSCRIPT 7.2

0.7

2.8

0.6

0.20

0.4

0.1

0.7

0.1

0.2

0.1

0.3

0.1

3.4

6.8

0.7

2.8

0.6

0.20

0.4

0.1

0.7

0.1

0.3

0.1

0.3

0.1

2.4

3.9

0.3

1.2

0.3

0.12

0.2

0.1

0.5

0.1

0.1

0.1

0.1

0.1

3.5

8.8

0.7

2.9

0.5

0.11

0.5

0.1

0.5

0.1

0.2

0.1

0.2

0.1

9.6

14.5

1.5

7.1

1.4

0.29

1.4

0.2

1.6

0.4

1.0

0.2

0.9

0.2

3.4

10.0

0.8

3.5

0.6

0.06

0.5

0.1

0.5

0.1

0.2

0.1

0.3

0.1

5.7

14.3

1.2

5.1

0.9

0.14

0.8

0.1

0.8

0.2

0.4

0.1

0.4

0.1

7.0

16.5

1.5

6.4

1.2

0.22

1.0

0.2

1.0

0.2

0.6

0.1

0.6

0.1

4.2

10.1

0.8

3.6

0.7

0.06

0.6

0.1

0.6

0.1

0.3

0.1

0.3

0.1

3.2

9.0

0.6

2.9

0.5

0.04

0.4

0.1

0.4

0.1

0.2

0.1

0.2

0.1

4.2

11.9

0.9

3.8

0.7

0.12

0.6

0.1

0.6

0.1

0.3

0.1

0.3

0.1

3.6

9.3

0.7

3.1

0.6

0.05

0.5

0.1

0.5

0.1

0.2

0.1

0.3

0.1

2.5

7.6

0.5

2.3

0.4

0.01

0.3

0.1

0.3

0.1

0.1

0.1

0.1

0.1

4.4

11.6

0.9

3.8

0.7

0.12

0.6

0.1

0.5

0.1

0.2

0.1

0.3

0.1

6.3

14.4

1.2

5.3

1.0

0.19

0.8

0.1

0.8

0.2

0.5

0.1

0.5

0.1

2.4

4.6

0.2

2.6

0.4

0.03

0.1

0.1

0.3

0.1

0.1

0.1

0.2

0.1

2.1

4.4

2.6

5.1

4.8

9.1

3.2

IP

SC R

NU

MA

D

TE

CE P

T

4.2

0.2

2.5

0.4

0.03

0.1

0.1

0.2

0.1

0.1

0.1

0.1

0.1

0.3

2.8

0.5

0.03

0.1

0.1

0.3

0.1

0.1

0.1

0.2

0.1

0.7

4.7

0.8

0.08

0.2

0.1

0.6

0.1

0.4

0.1

0.4

0.1

AC

TLM115 TLM110 TLM063 TLM050 TLM033 TVP210 TVP205 TVP195 TVP185 TVP180 TVP175 TVP170 TVP165 TVP160 TVP155 TVP150 TVP140 TVP135 TVP130 TVP125 TVP120 TVP115 TVP110 TVP105 LOD RSD

5.3

0.3

3.2

0.5

0.02

0.2

0.1

0.5

0.1

0.3

0.1

0.3

0.1

6.1

0.4

3.4

0.6

0.02

0.2

0.1

0.4

0.1

0.3

0.1

0.3

0.1

3.2

6.8

0.5

3.2

0.6

0.01

0.3

0.1

0.5

0.1

0.3

0.1

0.3

0.1

4.3

7.5

0.6

4.1

0.8

0.08

0.3

0.1

0.6

0.1

0.3

0.1

0.4

0.1

3.2

5.9

0.4

3.3

0.6

0.01

0.2

0.1

0.4

0.1

0.2

0.1

0.3

0.1

0.1 1.0

0.1 1.0

0.1 1.2

0.1 1.1

0.1 1.1

0.01 1.09

0.1 1.1

0.1 0.8

0.1 0.9

0.1 0.8

0.1 1.1

0.1 0.5

0.1 1.1

0.1 0.3

Th 0.5 0.3 0.1 0.2 0.2 0.2 12.3

U 2.6 3.9 4.0 5.4 4.5 2.7 4.3

3.6

Appendix A-3: Trace-element concentrations (mg/Kg) in all the samples. TZF-070 TZF-080 TZF-100 TZF-114 TZF-125 TZF-130 TZF-160

Mn 20 30 11 19 16 9 36

Sc --------

V 203 75 94 145 109 98 430

Cr 34.6 55.5 33.2 33.5 22.3 20.4 80.3

Co 19.0 18.5 36.4 17.3 51.2 24.4 12.1

Ni 19.4 22.2 22.1 30.5 14.8 16.4 27.8

57

Rb 7.8 7.0 2.8 4.3 2.4 2.7 95.3

Sr 210 234 158 155 55 102 108

Y 3.1 4.4 2.1 4.0 1.1 1.5 7.0

Cs 0.41 0.43 0.18 0.31 0.14 0.15 4.76

Ba 447 514 240 216 168 234 380

ACCEPTED MANUSCRIPT

58

24.2 5.6 7.9 2.4 7.6 11.6 7.0 7.3 15.9 5.2 2.6 3.1 9.4 2.1 2.2 3.1 11.0 4.0 1.8 4.1 2.8 3.6 6.2 9.8 2.6 4.1 7.2 4.7 6.8 3.3 Y 3.4 2.2 4.0 2.8 3.5 3.6 1.7 47.0 3.6 7.5 14.6 6.0 6.7 4.8 3.7 20.2 3.6 5.7 7.5 4.9 2.6 3.9 4.0 2.2 3.6 7.7 1.7

0.87 0.54 0.47 0.21 0.69 0.61 0.35 0.46 1.40 0.52 0.29 0.30 0.88 0.20 0.15 0.23 0.23 0.33 0.21 0.25 0.25 0.25 0.44 0.38 0.20 0.43 0.55 0.56 0.44 0.73 Cs 0.74 0.31 0.80 0.83 0.74 0.75 0.30 1.62 0.91 0.98 1.26 0.91 0.89 0.60 0.18 0.09 0.28 0.45 0.61 0.23 0.25 0.28 0.26 0.08 0.37 0.35 0.26

T

612 605 474 219 283 480 626 256 342 262 179 322 391 93 73 134 263 162 78 124 134 100 125 298 74 250 362 191 260 113 Sr 65 78 122 73 144 110 73 581 100 303 274 256 277 72 287 518 142 150 225 62 55 119 139 48 159 226 74

IP

18.2 10.6 7.8 2.7 13.0 14.0 5.4 8.0 30.9 10.8 6.1 4.9 18.9 2.8 1.9 4.3 3.8 7.4 2.9 3.8 4.9 5.6 9.8 7.7 3.1 3.7 8.0 5.2 5.2 2.3 Rb 2.4 4.8 2.7 2.8 2.4 2.6 3.8 24.2 4.2 12.9 19.7 5.2 4.4 1.7 4.1 3.3 1.2 5.8 7.1 1.4 0.1 1.7 0.3 0.1 2.7 3.8 2.1

SC R

39.3 23.6 29.7 10.4 35.3 39.2 16.7 18.7 58.4 26.3 12.2 15.4 39.7 12.6 15.2 15.2 11.4 23.6 19.0 20.9 15.2 20.1 15.6 28.7 15.2 25.7 30.3 18.7 20.2 17.9 Ni 19.5 20.5 24.2 19.8 19.8 19.4 11.6 41.5 20.1 18.9 29.1 27.3 22.8 10.7 4.9 1.2 11.2 25.2 29.6 16.4 16.9 21.5 17.7 8.8 18.2 25.7 15.7

NU

6.7 15.8 6.5 19.8 4.4 7.4 21.5 11.9 3.2 18.9 15.7 16.9 12.7 13.6 23.3 34.2 12.3 31.7 35.3 34.2 23.6 34.9 21.0 12.7 33.3 29.8 15.2 59.2 25.4 46.6 Co 54.6 51.1 35.5 50.6 61.3 79.8 65.6 15.3 51.4 29.9 52.1 29.4 46.9 89.0 54.7 20.6 73.4 12.3 10.4 25.5 37.3 23.6 41.6 44.3 30.6 21.9 31.3

MA

55.8 29.8 30.3 34.8 51.1 49.8 28.4 23.7 82.1 26.9 13.8 18.2 54.2 7.2 25.8 11.7 17.0 27.5 17.5 25.6 17.8 10.3 16.7 25.8 25.5 25.3 41.1 37.1 21.0 31.6 Cr 29.7 38.4 46.0 51.4 32.8 43.0 25.1 118.5 45.2 49.7 60.2 61.0 45.7 27.7 32.6 32.2 31.7 49.5 61.0 35.3 29.0 34.0 35.9 21.2 36.2 54.1 31.1

D

180 100 175 43 209 215 71 62 321 137 35 54 121 29 57 48 41 73 56 31 56 41 28 106 36 161 212 120 136 110 V 70 94 95 166 84 86 64 407 109 146 223 140 108 34 35 33 181 90 112 42 29 71 80 22 64 82 88

TE

-------------------------1.6 2.8 2.2 3.0 1.4 Sc 1.6 0.8 1.6 2.0 1.9 1.5 0.5 6.6 2.1 3.1 3.3 1.7 1.6 1.7 0.8 0.6 4.7 5.1 10.2 8.8 7.1 7.3 7.6 7.5 7.2 6.6 7.1

CE P

TLM-175 TLM-170 TLM-165 TLM-160 TLM-155 TLM-150 TLM-145 TLM-140 TLM-130 TLM-125 TLM-122 TLM-115 TLM-110 TLM-063 TLM-050 TLM-033 TVP-210 TVP-205 TVP-195 TVP-185 TVP-180 TVP-175 TVP-170 TVP-165 TVP-160 TVP-155 TVP-150

58 31 26 26 27 22 21 61 30 30 21 22 12 15 7 16 35 19 17 24 17 22 24 29 9 17 18 23 15 9 Mn 19 8 11 18 20 23 6 24 25 40 25 28 24 20 12 10 8 21 12 15 9 25 13 12 23 21 12

AC

TZF-170 TZF-200 TZF-205 TZF-215 TZF-220 TZF-225 TZF-235 TZF-245 TZF-255 TZF-260 TZF-280 TZF-290 TZF-300 TZF-310 TZF-320 TZF-330 TZF-340 TZF-350 TZF-360 TZF-370 TZF-375 TZF-385 TZF-390 TZF-400 TZF-410 TLM-215 TLM-200 TLM-195 TLM-190 TLM-185

343 351 486 287 359 456 624 385 305 297 146 202 293 205 160 306 205 419 379 300 253 368 382 297 271 449 210 1282 454 297 Ba 269 507 462 252 331 362 148 287 411 1458 412 409 352 301 336 271 164 207 289 157 180 271 185 169 268 300 197

1.0 0.5 0.4 0.2 0.6 5.5 0.3 0.3 1.3 0.7 0.2 0.2 0.7 0.2 0.2 0.2 0.3 0.3 0.2 0.5 0.4 0.2 0.4 0.4 1.2 1.2 2.0 1.3 1.5 0.5 Th 0.5 1.5 0.6 0.6 0.5 0.6 1.3 6.6 0.8 2.3 4.8 1.2 0.9 0.4 1.4 1.8 1.6 2.5 2.9 1.6 1.5 2.1 1.6 1.3 2.2 2.2 1.0

11.4 3.1 5.1 1.4 5.0 5.6 2.4 2.6 7.6 2.7 1.8 2.0 7.7 1.3 2.4 1.8 6.5 2.5 2.0 3.2 5.0 7.2 2.4 4.5 2.2 1.6 2.8 2.4 2.5 2.1 U 3.2 1.8 3.3 1.8 2.5 3.4 1.6 11.6 1.8 4.7 6.5 5.2 2.2 1.7 1.5 7.7 2.6 3.8 6.0 2.7 1.5 2.5 3.5 1.2 2.5 4.2 2.8

ACCEPTED MANUSCRIPT 48.9 33.5 26.2 83.8 49.0 49.8 95.0 97.2 0.1 0.6

21.2 19.7 16.5 20.6 30.4 22.5 25.1 12.3 0.1 0.4

2.5 2.3 6.6 1.7 3.8 3.1 4.5 2.8 0.1 1.6

60 60 136 95 86 194 62 41 1 0.7

1.0 1.6 4.6 4.7 3.4 3.7 4.0 2.7 0.1 1.1

NU MA D TE 59

0.29 0.24 0.36 0.27 0.33 0.20 0.53 0.30 0.01 1.12

T

31.6 30.4 39.7 22.7 39.4 32.8 45.9 25.6 0.1 0.5

IP

15 26 147 21 77 103 62 28 1 0.7

SC R

6.5 6.4 6.8 6.7 7.2 7.1 6.9 6.4 0.1 0.6

CE P

17 16 13 17 21 18 15 8 1 0.5

AC

TVP-140 TVP-135 TVP-130 TVP-125 TVP-120 TVP-115 TVP-110 TVP-105 LOD RSD

214 211 285 207 235 166 285 228 1 0.6

1.0 1.1 1.5 1.0 1.3 1.3 1.7 1.3 0.1 1.3

1.4 3.4 3.4 4.1 2.8 3.3 3.4 2.2 0.1 0.6

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

Appendix B

60

ACCEPTED MANUSCRIPT Appendix C-1: Correlation matrices for Mn, Co, and major elements in each sampling site. Zorca River CaO -1.00 0.17 0.07 0.27 1.00

MgO -0.60 0.59 0.59 0.62 0.51 1.00

Na2O -0.53 0.56 0.44 0.51 0.45 0.42 1.00

K2O -0.30 0.97 0.98 0.92 0.15 0.59 0.48 1.00

P2O5 -0.50 0.11 -0.04 0.15 0.51 0.08 0.58 0.11 1.00

Mn -0.44 0.50 0.47 0.56 0.38 0.42 0.44 0.43 0.06 1.00

Co 0.69 -0.52 -0.42 -0.52 -0.63 -0.49 -0.49 -0.48 -0.32 -0.39 1.00

K2O -0.07 0.96 0.98 0.96 0.09 0.29 0.60 1.00

P2O5 -0.44 -0.05 -0.11 0.03 0.41 -0.01 0.28 -0.08 1.00

Mn -0.59 0.14 0.14 0.12 0.56 0.71 -0.07 0.15 -0.09 1.00

Co 0.09 -0.58 -0.52 -0.56 -0.15 -0.14 -0.42 -0.54 -0.08 0.07 1.00

K2O -0.33 0.85 0.90 0.81 0.24 0.21 0.43 1.00

P2O5 -0.67 -0.02 0.01 -0.02 0.67 -0.01 0.86 0.19 1.00

Mn -0.15 0.36 0.33 0.35 0.08 0.08 0.15 0.32 0.10 1.00

Co 0.31 -0.29 -0.31 -0.31 -0.30 -0.29 -0.34 -0.42 -0.22 -0.04 1.00

T

Fe2O3 -0.41 0.95 0.86 1.00

IP

TiO2 -0.23 0.95 1.00

SC R

Al2O3 -0.32 1.00

NU

SiO2 Al2O3 TiO2 Fe2O3 CaO MgO Na2O K 2O P2O5 Mn Co

SiO2 1.00

La Molina Mine

SiO2 Al2O3 TiO2 Fe2O3 CaO MgO Na2O K 2O P2O5 Mn Co

SiO2 1.00

Al2O3 -0.03 1.00

TiO2 -0.01 0.98 1.00

Fe2O3 -0.03 0.99 0.98 1.00

CaO -1.00 0.10 0.01 0.05 1.00

TE CE P TiO2 -0.08 0.99 1.00

MgO -0.80 0.32 0.28 0.26 0.78 1.00

MA

Al2O3 -0.07 1.00

D

SiO2 1.00

AC

SiO2 Al2O3 TiO2 Fe2O3 CaO MgO Na2O K 2O P2O5 Mn Co

Na2O -0.01 0.72 0.69 0.73 0.00 0.05 1.00

Delicias-Villa Páez section Fe2O3 -0.07 0.87 0.86 1.00

CaO -1.00 -0.12 -0.06 -0.05 1.00

61

MgO -0.23 0.09 0.13 0.10 0.23 1.00

Na2O -0.84 0.06 0.14 0.14 0.84 0.27 1.00

ACCEPTED MANUSCRIPT Appendix C-2: Correlation coefficients (Rs) between Al2O3 and Co (plus TOC and S for Zorca River) and trace elements (even REEs) studied for the three sampling sites.

D

T

Delicias-Villa Páez Al2O3 Co 0.36 -0.04 Mn -0.02 -0.28 Sr -0.08 -0.16 V 0.36 -0.32 Cr 0.19 -0.21 Ni 0.97 -0.24 Rb 0.09 -0.26 Y 0.95 -0.16 Cs 0.74 -0.24 Ba 0.84 -0.40 Th -0.01 -0.25 U 0.45 -0.34 La 0.58 -0.40 Ce 0.54 -0.40 Pr 0.56 -0.36 Nd 0.52 -0.36 Sm 0.52 -0.36 Eu 0.39 -0.33 Tb 0.39 -0.37 Gd 0.31 -0.32 Dy 0.21 -0.31 Ho 0.21 -0.29 Er 0.17 -0.30 Tm 0.20 -0.29 Yb 0.18 -0.27 Lu 0.05 0.00 Sc 1.00 -0.28 Al2O3 -0.28 1.00 Co --S --TOC

NU

SC R

IP

La Molina Mine Al2O3 Co 0.14 0.07 Mn 0.11 -0.21 Sr 0.54 -0.22 V 0.63 -0.42 Cr 0.70 -0.43 Ni 0.91 -0.49 Rb 0.01 -0.06 Y 0.58 -0.14 Cs 0.04 0.03 Ba 0.65 -0.42 Th 0.05 -0.16 U 0.16 -0.15 La 0.42 -0.26 Ce 0.30 -0.21 Pr 0.30 -0.22 Nd 0.29 -0.20 Sm 0.25 -0.17 Eu 0.22 -0.19 Tb 0.20 -0.17 Gd 0.15 -0.13 Dy 0.11 -0.14 Ho 0.12 -0.12 Er 0.14 -0.15 Tm 0.14 -0.13 Yb 0.12 -0.14 Lu 0.69 -0.32 Sc 1.00 -0.58 Al2O3 -0.58 1.00 Co --S --TOC

MA

TOC 0.19 0.52 0.91 0.78 0.92 0.54 0.38 0.55 0.05 0.65 0.51 0.48 0.48 0.48 0.47 0.45 0.40 0.32 0.39 0.39 0.36 0.38 0.29 0.37 0.35 -0.51 -0.57 0.71 1.00

TE

CE P

AC

Mn Sr V Cr Ni Rb Y Cs Ba Th U La Ce Pr Nd Sm Eu Tb Gd Dy Ho Er Tm Yb Lu Sc Al2O3 Co S TOC

Zorca River Al2O3 Co S 0.50 -0.39 0.37 0.18 -0.59 0.14 0.59 -0.38 0.93 0.79 -0.53 0.75 0.65 -0.47 0.86 0.94 -0.47 0.71 0.28 -0.42 0.26 0.94 -0.46 0.70 0.16 -0.11 0.00 0.67 -0.39 0.47 0.30 -0.24 0.43 0.54 -0.49 0.35 0.62 -0.49 0.38 0.59 -0.48 0.38 0.55 -0.47 0.36 0.51 -0.47 0.35 0.42 -0.44 0.32 0.33 -0.40 0.26 0.39 -0.44 0.30 0.38 -0.44 0.32 0.34 -0.43 0.29 0.36 -0.43 0.31 0.24 -0.35 0.24 0.35 -0.45 0.31 0.29 -0.35 0.30 ---1.00 -0.52 0.63 -0.52 1.00 -0.34 0.63 -0.34 1.00 0.51 -0.57 0.71

62