Redalyc.U-Pb Geochronology of Detrital Zircons from the Venezuelan

Geologica Acta: an international earth science journal ISSN: 1695-6133 [email protected] Universitat de Barcelona España

NOGUERA, M.I.; WRIGHT, J.E.; URBANI, F.; PINDELL, J. U-Pb Geochronology of detrital zircons from the Venezuelan passive margin: implications for an Early Cretaceous Proto-Orinoco river system and Proto-Caribbean ocean basin paleogeography Geologica Acta: an international earth science journal, vol. 9, núm. 3-4, septiembre-diciembre, 2011, pp. 265-272 Universitat de Barcelona Barcelona, España

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U-Pb Geochronology of detrital zircons from the Venezuelan passive margin: implications for an Early Cretaceous Proto-Orinoco river system and Proto-Caribbean ocean basin paleogeography

1 2 1 * 3 4 M.I. NOGUERA J.E. WRIGHT F. URBANI J. PINDELL

1 Department of Geology, University of Georgia Athens, GA 30602

2 Current address: Swift Energy Operating, LLC 16825 Northchase Drive, Suite 400, Houston, TX 77060

3 FUNVISIS, El Llanito and Universidad Central de Venezuela, Escuela de Geología Final Calle Mara, Caracas, Venezuela

4 Department of Earth Science, Rice University Keith-Weiss Geological Laboratory 6100 Main Street, Houston, TX 77005 and Tectonic Analysis Ltd., Chestnut House, Burton Park, Duncton, West Sussex, GU28 0LH, England

* Corresponding author: James E. Wright, [email protected], phone: 706-542-4394, fax: 706-542-2425

ABS TRACT

The Guyana Shield has long been interpreted as the source of siliciclastic detritus within the Cretaceous passive margin strata of northern Venezuela. We have determined U-Pb ages of detrital zircons separated from Early Cretaceous strata of the passive margin. Although the Guyana shield is the probable source for much of the Archean, Paleoproterozoic and early Mesoproterozoic detrital zircon grains, there is a prominent age population (ca.0.95-1.2Ga) that is not easily explained as being derived from the shield. A western source in the Venezuelan and/or northern Colombian Andes is suggested for this detrital component. We propose that a Proto-Orinoco river system drained both the Guyana Shield and the Venezuelan and Colombian Andes and that branches of this river system were funneled through Triassic/Jurassic rift basins that formed during initial opening of the Proto- Caribbean Seaway. The detrital zircon age data have implications for paleogeographic reconstructions of the Caribbean region prior to the breakup of Pangea and the longevity of continental scale river systems.

KEYWORDS Detrital Zircon. Passive Margin. Venezuela.

265 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin

INTRODUCTION dominated by siliciclastic sedimentation above a regional transgressive peneplain. Regional transgression onto The provenance of sandstones as determined by U-Pb the subsiding passive margin led to onlap of continental detrital zircon geochronology has become a widely used to shallow marine facies, followed by deeper water tool in global plate tectonic reconstructions. For example, facies which reached a maximum in the Late Cretaceous it has been used to help reconstruct Pangea in the Caribbean (Turonian-Coniacian) and is reflected in the Cretaceous region prior to the opening of the Proto-Caribbean as a stratigraphic record by a gradual change from siliciclastic number of detrital zircon investigations have suggested a dominated sedimentation in the Early Cretaceous to more northern South American provenance for Paleozoic strata pelagic shale and carbonate sedimentation in the Late now found in Mexico (e.g. Weber et al., 2006, 2008; Ortega- Cretaceous (Pindell and Erikson, 1994). Obregon et al., 2009). In addition, currently geographically dispersed Jurassic to Cenozoic sediments of the Caribbean We have obtained a total of 560 detrital zircon region are interpreted to have been derived from northern analyses from six samples of siliciclastic Early Cretaceous Venezuela (e.g. Rojas-Agramonte et al., 2008; Pindell et passive-margin units along northern Venezuela (Fig. 1). al., 2009). However, there are no published U-Pb detrital Sample locations and analytical data are contained in the zircon provenance studies for the northern South American supplementary files. margin to test these hypotheses yet. We report the first U-Pb detrital zircon ages from the passive margin of Venezuela in order to establish a provenance barcode that can be used PASSIVE MARGIN SAMPLES to quantitatively assess Pangean paleogeography in this region. Four Early Cretaceous stratigraphic units (six samples) of the Venezuelan passive margin were sampled for detrital In addition, a number of detrital zircon investigations zircon dating (Fig. 1). The stratigraphic terminology of the have been used to provide evidence for the presence and/ passive margin strata of northern Venezuela varies from or location of continental scale paleofluvial drainage west to east. The samples for this study were collected systems (Riggs et al., 1996; Dickinson and Gehrels, 2003; from the Early Cretaceous Aguardiente (westernmost unit Prokopiev et al., 2008). Our data, in conjunction with sampled), Bobare, Araure and Barranquín (easternmost previous investigations, clearly identifies such a system unit sampled) formations. that operated in northern South America. A single sample of quartz arenite was collected from the Aguardiente Formation (Barremian-Aptian) which GEOLOGICAL SETTING contains quartz-rich sandstones with local glauconitic sandstone and limestone beds and is interpreted to Separation of North and South America during the have been deposited in a shallow marine deltaic setting breakup of western Pangaea created the Proto-Caribbean (Salvador, 1961). seaway and resulted in the establishment of an Early Cretaceous passive margin in northern Venezuela. During the Triassic and Jurassic, continental breakup led to formation of numerous rift basins that were filled with continental red beds and associated volcanic rocks (Yoris et al., 1997; Ramos, 2009). Although rocks associated with the early rifting phase of passive margin development are exposed in western Venezuela (Perijá and Mérida Andes) where they attain a thickness of 300 to 3400m (Schubert, 1986), in central and eastern Venezuela these deposits are buried by younger strata and are known only from drill hole data (Feo-Codecido et al., 1984). For example, the Espino Graben (Fig. 1) is a buried rift basin that trends WSW-ENE across northern Venezuela and is known from wells to contain as much as 1.5km of Jurassic red beds and volcanic rocks dated at 162Ma (Feo-Codecido et al., 1984; Motiscka, 1985; Rodríguez and Rodríguez, 2003). FIGURE 1 Simplified geologic map of northern Venezuela showing the The Triassic-Jurassic rifting phase was followed by location of Early Cretaceous passive margin samples collected for this the development of an Early Cretaceous passive margin study.

Geologica Acta, 9(3-4), 265-272 (2011) 266 DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin

Two samples of quartz arenite were analyzed from the most analyses, the cross-over in precision of 206Pb/238U Bobare Formation (Barremian-Albian) of northwestern and 206Pb/207Pb ages occurs at 0.8-1.0Ga. Common Pb Venezuela. Bellizzia and Rodríguez (1967) described correction is accomplished by using the measured 204Pb the unit as being composed of massive, sometimes and assuming an initial Pb composition from Stacey and conglomeratic, quartz-rich-sandstone, shale and siltstone Kramers (1975) (with uncertainties of 1.0 for 206Pb/204Pb and interpreted the Bobare to have been deposited in an and 0.3 for 207Pb/204Pb). Our measurement of 204Pb is unstable shelf environment. unaffected by the presence of 204Hg because backgrounds are measured on peaks (thereby subtracting any background One sample of a schistose quartz-sandstone from the 204Hg and 204Pb), and because very little Hg is present in the Araure Formation (Neocomian-Barremian?) was collected. argon gas. Inter-element fractionation of Pb/U is generally Renz and Short (1960) and Bushman (1967) described the ~20%, whereas apparent fractionation of Pb isotopes is unit as containing thick conglomerate layers, alternating generally ~2%. In-run analysis of fragments of a large with arkosic sandstone, quartz sandstone and silty shales; zircon crystal (generally every fifth measurement) with it is interpreted to have been deposited in continental to known age of 564±4Ma (2-sigma error) is used to correct shallow marine waters. for this fractionation. The uncertainty resulting from the calibration correction is generally 1-2% (2-sigma) Two samples (quartz arenites and sublitharenites) were for both 206Pb/207Pb and 206Pb/238U ages. The analytical sampled for zircons and analyzed from the Barranquín data are reported in the supplementary document files. Formation (Barremian-Aptian) of eastern Venezuela. Uncertainties shown in these tables are at the 1-sigma The unit is composed of quartz sandstone, intercalated level, and include only measurement errors. Interpreted with shale and occasional limestone, and is considered to ages are based on 206Pb/238U for <1000Ma grains and on have been deposited in deltaic to internal inner shelf (bar) 206Pb/207Pb for >1000Ma grains. This division at 1000Ma environments (Pindell and Erikson, 1994; Erikson and results from the increasing uncertainty of 206Pb/238U Pindell, 1998a, b). ages and the decreasing uncertainty of 206Pb/207Pb ages as a function of age. The resulting interpreted ages are shown on relative age-probability diagrams (from ANALYTICAL METHODS Ludwig, 2003). These diagrams show each age and its uncertainty (for measurement error only) as a normal U-Pb geochronology of zircons was conducted distribution, and sum all ages from a sample into a by laser ablation multicollector inductively coupled single curve. plasma mass spectrometry (LA-MC-ICPMS) at the Arizona LaserChron Center. Analytical protocols We obtained 560 U-Pb zircon ages (Supplementary followed Gehrels et al., 2006. The analyses involve Data), derived from six samples of four Early Cretaceous ablation of zircon with a New Wave/Lambda Physik passive margin formations of northern Venezuela. DUV193 Excimer laser (operating at a wavelength of 193nm) using a spot diameter of 30microns. The ablated material is carried in helium into the plasma source of PROVENANCE OF THE EARLY CRETACEOUS a GVI Isoprobe, which is equipped with a flight tube of PASSIVE MARGIN sufficient width that U, Th, and Pb isotopes are measured simultaneously. All measurements are made in static mode, Previous investigations interpreted the Early using 1011 ohm Faraday detectors for 238U, 232Th, 208Pb, and Cretaceous siliciclastic passive margin strata to have 206Pb, a 1012 ohm faraday collector for 207Pb, and an ion- been derived entirely from the Guyana Shield to the counting channel for 204Pb. Ion yields are ~1.0mv per ppm. south (van Andel, 1958; González de Juana et al., 1980), Each analysis consists of one 12-second integration on with few indications of any particular drainage systems. peaks with the laser off (for backgrounds), 12 one-second The ages of detrital zircons from the passive margin integrations with the laser firing, and a 30 second delay units range from late Archean (2731Ma) to Silurian to purge the previous sample and prepare for the next (415Ma), and all samples display similar distribution analysis. The ablation pit is ~12 microns in depth. For patterns with the exception of the Araure Formation each analysis, the errors in determining 206Pb/238U and (Fig. 2). The data are similar to U-Pb detrital zircon 206Pb/204Pb result in a measurement error of ~1-2% ages obtained from the modern Orinoco River and its (at 2-sigma level) in the 206Pb/238U age. The errors in tributaries which drain the northern Andes of Colombia measurement of 206Pb/207Pb and 206Pb/204Pb also result in and Venezuela as well as the Guyana Shield (Goldstein ~1-2% (at 2-sigma level) uncertainty in age for grains et al., 1997). Prominent Precambrian age peaks in the that are >1.0Ga, but are substantially larger for younger passive margin samples occur at ca.2.0, 1.8, 1.4 to 1.6, grains due to low intensity of the 207Pb signal. For and 1.2- 0.95Ga. There are also a few grains that gave

Geologica Acta, 9(3-4), 265-272 (2011) 267 DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin

Fig. 3) and may also be present in the Mérida Andes Combined Data (Figs. 1, 3; Burkley, 1976). Paleozoic strata from these areas are also a potential source for detrital zircons but there are no published data to evaluate that possibility. We speculate that the ca. 0.95-1.2Ga age population Barranquín of detrital zircon was derived from the basement rocks of Colombia and possibly the Mérida Andes, and their Paleozoic cover, rather than the Sunsas Province senso stricto. The paleogeographic implications of this interpretation are discussed below. Araure There are several potential source areas for the Paleozoic and late Neoproterozoic detrital populations (ca. 415-650Ma) which only account for approximately

Relative Probability 6 percent of the total number of analyses. The Neoproterozoic Brasiliano and Pampean Provinces Bobare contain ages ranging from ca. 0.7-0.5Ga, and the Famatinian arc terrane is a potential source terrane for zircons in the 0.5-0.4Ga age range (Fig. 3). These Aguardiente provinces are, however, located extremely far from the Early Cretaceous passive margin of Venezuela. Other potential source regions exist in the Mérida Andes and Detrital Zircon Age (Ma) the Perijá Range (Fig. 2). These areas are uplifted blocks that contain Paleozoic and Precambrian rocks overlain FIGURE 2 Probability density plot of U-Pb zircon detrital zircon ages by Cretaceous passive margin strata. In addition, the from Early Cretaceous passive margin samples. Cordillera de la Costa Belt of northern Venezuela and the northern Colombian Andes are possible source regions for this detrital population. The older rocks late Archean ages. In addition, about 6 percent of the in all of these areas probably represent windows into grains fall into the ca. 400-650Ma age range. the crust that underlies much of the Llanos Cenozoic foreland to the Colombian and Venezuelan thrustbelts The Archean, Paleoproterozoic, and early Mesopro- (Feo-Codecido et al., 1984; Fig. 1). Unfortunately, terozoic detrital zircon populations are a good match to little modern geochronology has been done in these known age provinces in the Guayana Shield (Fig. 3). regions. In the Cordillera de la Costa area (Fig. 1) Sisson Archaen rocks are present in the Imataca Complex of the et al. (2005) reported early Paleozoic (Cambrian and Central Amazonian Province, and age peaks of ca.1.8 Ordovician) U-Pb zircon ages from several granitoid and 2.0Ga plus a few grains of ca.2.1 and 2.2Ga are a intrusions. Urbani et al. (2007) also reported a Cambrian good match to the Maroni-Itacaiunal, Ventuari-Tapajos (508Ma) U-Pb zircon age from the Todasana metadiorite and Río Negro-Jurena Provinces (Fig. 3). The ca. 1.5Ga located in the Cordillera de la Costa belt. Viscarret et al. age peak is most likely derived from Rapakivi granites, (2007) reported early Paleozoic (Cambro/Ordovician) including the 30,000km2 Parguaza Batholith, which as well as late Paleozoic (Permian) U-Pb zircon ages intrude older rocks of the Amazonia Craton (Gaudette determined on volcanic and plutonic rocks from the El et al., 1978; Mendoza, 1978, 2005), especially within Baúl area (Fig. 1). Burkley (1976) carried out an extensive the Ventuari-Tapajos Province. U-Pb zircon geochronology project in the Mérida Andes. Although all his samples are complicated by Pb loss and/ The most remarkable feature of our dataset is the or the presence of inherited older zircon, he was able to large proportion of detrital zircons giving prominent determine early Paleozoic ages (Devonian, Silurian and peaks at ca. 1.2 and 0.95-1.1Ga. The only known Ordovician) on a number of granitoid bodies as well as southern source area for this age population is the some late Neoproterozoic ages of ca. 600Ma from three Sunsas province that lies far to the south in the other granitoid intrusions. Thus, a local Venezuelan Amazonian craton of Bolivia (Fig. 3). Rocks of this source region is a possibility for this detrital component. age, however, are also known from the basement inliers Paleozoic strata of Colombia and the Mérida Andes of of the northern Andes of Colombia (Santa Marta, Venezuela are also a potential source region for this Santander, and Garzón massifs; e.g. Kroonemberg, detrital population, but no detrital zircon geochronology 1982; Restrepo-Pace et al., 1997; Cordani et al., 2005; exists for these rock units.

Geologica Acta, 9(3-4), 265-272 (2011) 268 DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin

AMAZONIAN CRATON

ANDEAN BELT a

FIGURE 3 Generalized geologic map of the South American cratons depicting major tectonic provinces. Modified from Cordani et al. (2000) and Tassi- nari et al. (2000).

PALEOGEOGRAPHIC IMPLICATIONS FOR THE Orinoco river system was responsible for the detrital PASSIVE MARGIN OF VENEZUELA zircon provenance of the Early Cretaceous passive margin of Venezuela. Our sample localities are shown in Figure The modern Orinoco river system drains both the (4A) in relation to the Jurassic Espino and Uribante rift Guyana Shield and the Andes of Colombia and Venezuela structures. Note that the deltaic to shallow shelf deposits and contains a population of detrital zircons that is similar of the Barranquín formation occur on strike with the to our Early Cretaceous passive margin samples, including Espino Graben, and the Aguardiente and Bobare sample the prominent ca. 0.95-1.2Ga population (Goldstein et collection sites lie above the Uribante rift. We suggest that al., 1997). Kasper and Larue (1986) attributed the great a paleo-river system drained eastern Colombia and western thickness of Paleocene and Eocene clastic detritus in Venezuela and flowed down broad valleys above both the the Lake Maracaibo Basin (Fig. 1) to a north-flowing Espino Graben and Uribante rifts, following the principal paleofluvial system that drained the Colombian Andes and that rifts are where subsidence is greatest, thus supplying Guyana shield regions which they called the Proto-Orinoco the 0.95-1.2Ga detrital zircon component (Fig. 4A) before River. In addition, Hoorn et al. (1995) likewise came to the and during initial marine transgression in these areas. conclusion that a northwest-flowing Proto-Orinoco River system drained the Andes and the Guyana shield prior to the Late Miocene forming a delta in the Lake Maracaibo REGIONAL PALEOGEOGRAPHIC IMPLICATIONS region. By the Middle Miocene, uplift in Colombia and the Mérida Andes of Venezuela is postulated to have deflected Rojas-Agramonte et al. (2008) analysed 19 detrital the paleofluvial system into a more east-west orientation, zircon grains from the clastic sediments of the Early (?) marking the beginning of the current Orinoco drainage to Late Jurassic (Oxfordian) San Cayetano Formation of (Díaz de Gamero, 1996).We suggest that a similar Proto- western Cuba. The San Cayetano Formation is considered

Geologica Acta, 9(3-4), 265-272 (2011) 269 DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin

to have been deposited in and above rift basins developed Amazonian craton as previously discussed and as shown during breakup of Pangea during initial opening of the by our detrital zircon data (Fig. 2). Also, their data (albeit Proto-Caribbean (Pindell, 1985; Martön and Buffler, very limited) exhibit very similar age populations to those 1994, 1999; Iturralde-Vinent, 2003). Although a number of the Venezuelan passive margin strata in support of their of possible source areas have been suggested (including general paleogeographic model. It thus appears that the a Laurentian source), Rojas-Agramonte et al. (2008) Espino Graben and Uribante rifts hosted a Jurassic to Early concluded from their detrital zircon data that the San Cretaceous Proto-Orinoco river system. Cayetano Formation most likely had a Gondwanan (South American) provenance. They further speculated The paleofluvial system postulated here for the Jurassic and that the basin was geographically located off the current Early Cretaceous marked the beginning of a continental-scale northeastern Venezuelan margin near the termination of drainage system that was resumed, after middle Cretaceous the Espino Graben (Fig. 4B) and that it was fed in part by drowning of the paleo-river valleys (Villamil and Pindell, 1998), a river system running through the Espino and Uribante in the Paleogene, when the Caribbean collisional foredeep was rifts. Although not explicitly discussed in their paper, the first imposed on the western reaches of the northern South occurrence of a ca.1.5-1.6Ga detrital zircons in the San American passive margin (Pindell et al., 1998). It continues today Cayetano Formation strongly supports a South American as the Orinoco river, after a long history of persistent eastward provenance as this age range lies within the Laurentian deflection along the Venezuela-Trinidad margin due to the magmatic gap but is a prominent age found within the eastward-younging oblique collision of the Caribbean Plate and associated eastward lengthening of the zone of orogenic uplift (Díaz de Gamero, 1996). Thus, the continental scale Orinoco fluvial system seems to have persisted since the initial formation of the northern South American passive margin during the breakup of Pangea, suggesting that the longevity of such river systems may be the same order of magnitude as that of plate boundaries (eg. Prokopiev et al., 2008).

ACKNOWLEDGMENTS

This paper is a contribution to the BOLIVAR project supported by NSF grants EAR 0607533 and 0087361 to Wright, and support from NSF EAR-0003572 is acknowledged by Pindell. The GEODINOS project (Fundación Venezolana de Investigaciones Sismológicas and Universidad Central de Venezuela) provided logistical support in the field. Noguera received grant support from AAPG, the University of Georgia, Miriam Watts–Wheeler Scholarship Fund, and the Latin American and Caribbean Studies Institute at the University of Georgia. University of Georgia undergraduate students Ted Lord, Emily First, Auggie Parinello and Corin Steadman helped with mineral spearation and/or the LA-MC-ICPMS analyses. Student travel and LA-MC-ICPMS analyses were subsidized by the Arizona LaserChron center á through NSF grants EAR 0443387 and 0732436.

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Geologica Acta, 9(3-4), 265-272 (2011) 271 DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin

provenance and palaeogeography. In: James, K.H., Lorente, belts of northern Venezuela: Old ones, new ones, and their M.A., Pindell, J.L. (eds.). The Origin and Evolution of the impact on regional geology. In: Avé-Lallemant, H., Sisson, Caribbean Plate. London, Geological Society, 328 (Special V., (eds.). Caribbean-South American Plate Interactions, Publications), 739-794. Venezuela. Geological Society of America, 394 (Special Prokopiev, A.V., Toro, J., Miller, E.L., Gehrels, G.E, 2008. Paper), 91-117. The paleo-Lena River-200 m.y. of transcontinental zircon Stacey, J.S., Kramers, J.D., 1975. Approximation of terrestrial transport in Siberia. Geology, 36(9), 699-702. lead isotope evolution by a twostage model. Earth and Ramos, V.A., 2009. Anatomy and global context of the Andes: Planetary Science Letters, 26, 207-221. Main geologic features and the Andean orogenic cycle. In: Tassinari, C.C.G., Bettencourt, J.S., Geraldes, M.C., 2000. The Kay, S.M., Ramos, V.A., Dickinson, W.R. (eds.). Backbone Amazon craton. In: Cordani, U.G., Milani, E.J., Thomaz- of the Americas: Shallow subduction, plateau uplift, and Filho, A., Campos, D.A. (eds.). Tectonic evolution of South ridge and terrane collision. Geological Society of America America. Rio de Janeiro, 31st International Geological Memoir, 204, 31-65. Congress, 41-95. Renz, O., Short, K.C., 1960. Estratigrafía de la región comprendida Urbani, F., Wright, J., Grande, S., 2007. La Metadiorita de entre el Pao y Acarigua, estados Cojedes y Portuguesa. Todasana, Cordillera de la Costa, estado Vargas: Geología y Caracas, Memoria III Congreso Geológico Venezolano, 1, geocronología. Caracas, Geos, 39, 93-94 and 33pp in CD. 277-315. Van Andel, T., 1958. Origin and classification of Cretaceous, Restrepo-Pace, P.A., Ruiz, J., Gehlers, G., 1997. Geochronology Paleocene and Eocene sandstones of Western Venezuela. and Nd isotopic data of Grenville-age rocks in the Colombian American Association of Petroleum Geologists Bulletin, 42, Andes: new constraints for Late Proterozoic-Early Palezoic 734-763. paleocontinental reconstructions of the Americas. Earth and Viscarret, P., Wright, J.E., Urbani, F., 2007. Dataciones U/Pb Planetary Science Letters, 150, 427-441. SHRIMP en circón de rocas del macizo de El Baúl, estado Riggs, N.R., Lehman, T.M., Gehrels, G.E., 1996. Detrital zircon Cojedes, Venezuela. Caracas, Geos, 39, 94-95 and 37pp in link between headwaters and terminus of the Upper Triassic CD. Chinle-Dockum paleoriver system. Science, 273, 97-100. Villamil, T., Pindell, J.L., 1998. The Mesozoic of northern South Rodríguez, I., Rodríguez, J., 2003. Gravity and magnetic America: foundations for sequence stratigraphic studies in modelling across the Guárico Sub-basin, Espino Graben, passive margin strata deposited during non-glacial times. In: Venezuela. Institut de Recherche pour le développement Pindell, J.L., Drake, C.L. (eds.). Paleogeographic Evolution (IRD) – Université Paul Sabatier, Andean Geodynamics, and Non-glacial Eustasy, northern South America. Tulsa, Extended Abstracts, 533-536. Society for Sedimentary Geology (SEPM), 58 (Special Rojas-Agramonte, Y., Kroner, A., Pindell, J., 2008. Detrital Publications), 283-318. zircon geochronology of Jurassic sandstones of western Cuba Weber, B., Schaaf, P., Valencia, V.A., Iriondo, A., Ortega–Gutiérrez, (San Cayetano Formation): Implications for the Jurassic F., 2006. Provenance ages of late Paleozoic sandstones (Santa paleogeography of the NW Proto-Caribbean. American Rosa Formation) from the Maya block, SE Mexico. Implications Journal of Science, 308, 639-656. on the tectonic evolution of western Pangea. Revista Mexicana Salvador, A., 1961. Guidebook to the geology of northeastern de Ciencias Geologicas, 23, 262-276. Trujillo. Maracaibo, Sociedad Venezolana de Geólogos, Weber, B., Valencia, V.A., Schaaf, P., Pompa-Mera, V., Ruiz, Region Occidental, 3, 33pp. J., 2008. Significance of provenance ages from the Chiapas Schubert, C., 1986. Stratigraphy of the Jurassic La Quinta Massif Complex (southeastern Mexico): Redefining the Formation, Mérida Andes, Venezuela: type sections. Paleozoic basement of the Maya block and its evolution in a Zeitschrift der Deutsche Geologische Gesellschaft, 137, 391- Peri-Gondwanan realm. Journal of Geology, 116, 619-639. 411. Yoris, F., Ostos, M., Zamora, L., 1997. Petroleum Geology Sisson, V., Avé Lallemant, H.G., Ostos, M., Blythe, A.F., Snee, of Venezuela. In: Singer, J.M. (ed.). 1997 Venezuela Well L.W., Copeland, P., Wright, J.E., Donelick, R.A., Guth, L.R., Evaluation Conference. Schlumberger Surenco. Houston, 2005. Overview of radiometric ages in three allochthonous Jolley Printing, 1-44. Manuscript received November 2010; revision accepted May 2011; published Online June 2011.

Geologica Acta, 9(3-4), 265-272 (2011) 272 DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin

ELECTRONIC APPENDIX

Sample Number Unit Longitude W Latitude N VMN-7 Aguardiente 70.109 10.1466 VMN-16 Bobare 69.448 10.4371 VMN-17 Bobare 69.4083 10.4024 VMN-18 Araure 69.097 9.6701 VMN-32 Barranquín 64.5351 10.2328 VMN-35 Barranquín 64.384 10.2919

Geologica Acta, 9(3-4), 265-272 (2011) I DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 6.6 4.3 6.4 8.7 5.0 5.7 7.3 24.3 19.3 22.9 26.8 33.1 33.1 42.7 29.4 31.1 13.8 32.8 18.0 30.0 26.7 31.2 24.6 27.3 19.9 27.3 29.9 15.2 18.9 20.3 27.5 35.8 25.1 23.3 20.5 22.8 25.8 25.4 35.1 29.2 10.8 20.6 22.6 76.5 21.4 ± (Ma) 474.1 988.5 423.0 428.6 651.9 441.3 517.6 599.7 500.4 494.5 592.5 494.0 956.1 1705.8 1807.4 1798.3 1256.4 1412.9 1444.3 1730.1 1216.3 1025.9 1872.7 1200.0 1397.2 1546.2 2719.3 1044.7 1550.6 1580.2 1805.1 1504.3 1738.6 1363.1 1323.0 1811.1 1464.6 2097.1 1418.4 1815.2 1559.6 1245.2 1531.6 1096.6 1819.9 (Ma) Best Best age 24.3 19.3 22.9 26.8 33.1 33.1 42.7 67.0 92.9 29.4 21.7 31.1 32.8 18.0 22.8 30.0 26.7 96.5 31.2 51.0 24.6 27.3 19.9 27.3 29.9 22.2 18.9 20.3 85.2 27.5 25.1 23.3 20.5 22.8 25.8 25.4 35.1 29.2 34.6 29.1 39.3 20.6 76.5 21.4 ± 124.0 (Ma) Pb* Pb* 467.8 988.5 429.0 375.6 791.5 425.1 446.5 700.8 488.2 599.8 599.7 519.5 955.6 1705.8 1807.4 1798.3 1256.4 1412.9 1444.3 1730.1 1216.3 1025.9 1872.7 1200.0 1397.2 1546.2 2719.3 1044.7 1550.6 1580.2 1805.1 1504.3 1738.6 1363.1 1323.0 1811.1 1464.6 2097.1 1418.4 1815.2 1559.6 1245.2 1531.6 1096.6 1819.9 206 207 8.2 8.0 21.9 13.4 12.3 18.4 12.3 17.9 16.4 14.5 11.0 15.2 20.2 18.9 12.2 12.1 12.1 14.9 17.5 17.7 15.4 12.1 16.9 10.9 11.5 17.0 16.2 13.1 24.5 20.4 17.7 34.2 17.9 15.9 18.2 14.5 12.7 15.7 16.8 12.7 11.2 11.7 19.7 26.1 16.7 ± (Ma) U Pb* 473.0 965.1 423.9 420.4 684.1 438.7 504.7 621.3 498.2 513.7 594.0 498.6 956.0 1632.1 1800.4 1778.7 1263.0 1371.1 1243.7 1686.3 1124.1 1000.8 1880.3 1200.5 1368.4 1551.2 2612.6 1035.6 1513.4 1519.4 1799.0 1472.3 1674.2 1342.9 1313.6 1816.7 1401.6 2073.9 1385.4 1775.4 1504.3 1211.9 1522.4 1063.5 1814.6 235 207 Apparent ages (Ma) ages Apparent 6.6 8.9 4.3 6.4 8.7 5.0 5.7 9.2 7.3 9.5 14.0 15.7 27.8 11.5 19.9 15.4 27.1 22.6 13.8 16.4 16.1 22.7 13.8 20.6 13.3 20.8 15.7 15.2 38.8 32.0 22.8 35.8 24.4 21.9 26.2 17.6 12.3 19.1 13.5 10.9 10.8 13.5 22.6 10.1 24.9 ± (Ma) U* Pb* 474.1 954.8 423.0 428.6 651.9 441.3 517.6 599.7 989.3 500.4 494.5 592.5 494.0 956.1 1575.5 1794.4 1762.1 1266.8 1344.4 1131.1 1651.3 1077.0 1887.3 1200.7 1350.1 1554.9 2477.2 1031.3 1487.0 1476.1 1793.6 1450.1 1623.2 1330.1 1307.7 1821.5 1360.6 2050.6 1364.0 1741.8 1465.3 1193.2 1515.8 1047.5 1809.9 238 206 0.25 0.60 0.69 0.82 0.59 0.69 0.65 0.43 0.33 0.35 0.76 0.82 0.91 0.71 0.89 0.69 0.80 0.22 0.52 0.39 0.56 0.59 0.52 0.69 0.73 0.52 0.95 0.95 0.90 0.80 0.89 0.85 0.73 0.89 0.61 0.60 0.67 0.48 0.56 0.77 0.76 0.68 0.80 0.26 0.80 corr. error 1.5 1.0 1.0 1.8 1.0 1.6 1.5 1.0 1.0 1.6 1.9 2.3 2.2 1.0 2.1 1.5 1.9 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.6 1.0 3.2 3.0 2.2 1.9 7.5 2.1 1.4 2.1 1.0 1.0 1.3 1.0 1.0 1.9 1.5 1.0 2.5 1.0 1.6 ± (%) U Pb* 0.0763 0.2769 0.3210 0.3144 0.2172 0.2319 0.1918 0.1596 0.0678 0.0687 0.2920 0.1818 0.1064 0.3401 0.0709 0.2047 0.2330 0.0836 0.2728 0.0975 0.4685 0.1735 0.1659 0.2594 0.2573 0.3208 0.0807 0.2523 0.2863 0.2292 0.0797 0.2249 0.3265 0.2350 0.3745 0.2356 0.3102 0.2552 0.2033 0.0963 0.0796 0.2651 0.1599 0.1764 0.3241 238 206 5.8 1.7 1.5 2.2 1.7 2.4 2.3 2.3 3.2 4.4 2.5 2.8 2.5 1.4 2.3 2.1 2.3 4.5 1.9 2.6 1.8 1.7 1.9 1.5 2.2 1.9 3.3 3.2 2.5 2.4 8.5 2.4 1.9 2.4 1.6 1.7 1.9 2.1 1.8 2.5 2.0 1.5 3.2 4.0 2.0 ± (%) Isotope ratios Isotope U* Pb* 0.5934 3.9897 4.8895 4.7650 2.4690 2.8587 2.4036 1.5869 0.5181 0.5129 4.2635 2.0255 0.9616 5.3717 0.5405 2.2619 2.8485 0.6438 3.6076 0.8440 1.7730 1.6794 3.4394 3.4655 4.8809 0.6334 3.2629 4.2008 2.7528 0.6585 2.6461 4.9843 2.9765 6.7098 2.9133 4.7460 3.3996 2.2986 0.7951 0.6340 3.4787 1.5638 1.8502 4.9720 235 207 12.1056 5.6 3.8 1.3 1.1 1.3 1.4 1.7 1.7 2.1 3.0 4.1 1.6 1.6 1.0 1.0 1.0 1.5 1.4 4.3 1.7 2.4 1.5 1.4 1.6 1.1 1.5 1.6 1.0 1.0 1.1 1.4 3.9 1.3 1.3 1.1 1.3 1.3 1.4 1.9 1.5 1.6 1.3 1.1 1.9 1.2 ± (%) Pb* Pb* 9.5679 9.0510 9.0964 9.4420 8.7304 5.3367 9.0622 9.3984 9.0325 7.6959 9.0124 8.9888 206 207 17.7328 13.1479 12.1272 11.1848 11.0021 13.8714 18.0454 18.4810 13.4915 12.3779 15.2595 18.0769 12.4806 11.2770 17.9046 10.4255 15.9285 13.6182 10.4007 10.2378 17.5705 10.6598 11.4783 16.6953 11.7191 10.8854 11.1524 10.3510 12.1967 16.6961 17.3221 10.5063 14.0971 1.7 1.8 2.6 2.3 1.9 3.1 5.7 1.5 0.9 2.6 1.5 2.1 2.7 2.7 2.9 5.7 1.5 1.8 3.2 2.3 0.9 2.0 5.2 1.4 3.5 5.0 3.6 3.8 1.7 2.7 1.5 1.8 1.2 2.1 5.7 1.3 2.9 1.2 1.3 3.7 4.3 2.7 2.5 2.9 1.7 U/Th 7716 8750 3304 4636 7878 5660 4874 8688 3436 4476 8036 7260 4764 Pb Pb 23662 24674 29192 10662 14648 11662 18022 32606 11012 19184 11116 19058 15116 14992 10330 16602 80546 36986 28766 60090 12628 13312 14620 44220 24314 26340 20970 25030 11912 14824 15084 18190 206 204 50 75 49 99 89 76 66 66 235 217 268 107 187 162 442 259 285 181 553 108 212 227 181 166 252 150 228 680 273 322 270 576 350 126 110 523 131 207 189 277 272 370 150 260 118 U (ppm) Analysis VMN7-30 VMN7-44 VMN7-43 VMN7-42 VMN7-41 VMN7-40 VMN7-28 VMN7-27 VMN7-22 VMN7-39 VMN7-37 VMN7-36 VMN7-35 VMN7-34 VMN7-26 VMN7-25 VMN7-24 VMN7-21 VMN7-20 VMN7-19 VMN7-46 VMN7-38 VMN7-33 VMN7-32 VMN7-31 VMN7-23 VMN7-18 VMN7-17 VMN7-16 VMN7-15 VMN7-14 VMN7-13 VMN7-12 VMN7-11 VMN7-10 VMN7-8 VMN7-7 VMN7-6 VMN7-5 VMN7-4 VMN7-3 VMN7-2 VMN7-45 VMN7-9 VMN7-1

Geologica Acta, 9(3-4), 265-272 (2011) II DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 6.2 6.5 8.0 4.1 8.5 19.5 41.8 45.8 38.6 21.3 50.3 22.5 19.9 18.4 27.8 10.2 18.8 39.7 38.1 40.3 18.4 19.6 23.9 40.6 18.2 58.3 31.8 29.8 18.3 27.7 43.7 20.3 58.4 25.6 41.9 22.5 22.9 23.4 38.4 24.4 52.0 19.8 31.7 30.5 ± 123.7 (Ma) 996.4 655.5 613.6 506.6 850.6 415.1 532.4 1419.7 1717.7 1548.5 1454.3 1161.8 1254.3 1432.0 1729.9 1406.6 1592.3 1017.7 1783.2 1174.9 1243.1 1888.8 1257.5 1730.6 1388.3 1808.9 1419.9 1813.1 1240.2 1750.8 1896.7 1611.5 1844.8 1447.7 1478.0 1410.1 1815.3 1937.0 1654.6 1134.3 1509.8 1876.1 1210.9 1165.9 1457.2 (Ma) Best Best age 41.8 19.5 45.8 38.6 21.3 50.3 41.4 22.5 19.9 18.4 27.8 40.8 18.8 39.7 38.1 40.3 18.4 19.6 23.9 40.6 18.2 58.3 31.8 29.8 18.3 27.7 43.7 20.3 58.4 25.6 41.9 22.5 22.3 56.7 22.9 23.4 30.7 38.4 28.8 24.4 52.0 19.8 31.7 30.5 ± 123.7 (Ma) Pb* Pb* 996.4 629.4 613.8 486.1 828.5 409.2 537.4 1419.7 1717.7 1548.5 1454.3 1161.8 1254.3 1432.0 1729.9 1406.6 1592.3 1017.7 1783.2 1174.9 1243.1 1888.8 1257.5 1730.6 1388.3 1808.9 1419.9 1813.1 1240.2 1750.8 1896.7 1611.5 1844.8 1447.7 1478.0 1410.1 1815.3 1937.0 1654.6 1134.3 1509.8 1876.1 1210.9 1165.9 1457.2 206 207 6.7 5.8 8.8 10.8 14.8 37.8 18.8 11.6 19.1 10.4 11.0 11.1 14.9 15.9 11.9 11.4 14.2 59.7 15.2 16.5 19.0 10.2 13.6 19.2 11.9 24.7 17.1 14.6 11.7 15.8 20.4 40.1 25.0 13.1 19.8 20.2 14.1 16.6 30.8 17.7 12.8 48.8 13.8 12.9 14.7 ± (Ma) U Pb* 649.7 613.6 502.9 844.5 414.2 533.3 1386.5 1008.8 1569.1 1556.4 1464.7 1137.7 1262.7 1423.0 1739.3 1390.3 1591.0 1017.4 1636.7 1190.0 1252.5 1893.1 1252.4 1728.0 1412.1 1806.4 1444.6 1829.1 1248.8 1717.4 1902.8 1584.1 1738.4 1456.7 1483.2 1426.5 1789.5 1940.8 1657.2 1111.8 1503.5 1585.3 1217.8 1142.9 1462.3 235 207 Apparent ages (Ma) ages Apparent 9.9 6.2 9.4 6.5 8.0 4.1 8.5 12.3 52.6 16.1 13.2 12.1 11.5 12.7 22.6 18.8 10.2 14.1 38.0 10.9 11.4 32.2 11.4 15.1 17.7 15.7 13.1 16.0 15.4 14.9 16.5 13.9 68.2 13.1 13.3 17.7 31.7 16.8 51.9 17.9 13.4 66.3 18.6 10.4 13.1 ± (Ma) U* Pb* 655.5 613.6 506.6 850.6 415.1 532.4 1365.1 1014.5 1461.0 1562.3 1471.9 1125.0 1267.6 1417.0 1747.1 1379.7 1590.1 1017.3 1525.2 1198.4 1258.0 1897.1 1249.4 1725.9 1427.9 1804.2 1461.4 1843.1 1253.7 1690.0 1908.4 1563.6 1651.3 1462.8 1486.9 1437.6 1767.4 1944.3 1659.2 1100.4 1499.1 1376.0 1221.7 1130.8 1465.9 238 206 0.70 0.46 0.85 0.49 0.67 0.42 0.46 0.66 0.69 0.83 0.72 0.68 0.71 0.45 0.38 0.46 0.44 0.89 0.71 0.61 0.55 0.71 0.31 0.50 0.66 0.71 0.54 0.39 0.97 0.31 0.59 0.53 0.86 0.80 0.62 0.35 0.94 0.68 0.59 0.79 0.61 0.88 0.86 0.53 0.53 corr. error 1.0 1.1 4.0 1.2 1.0 1.2 1.0 1.0 1.0 1.5 1.5 1.8 1.0 1.0 2.8 1.0 1.0 2.0 1.0 1.0 1.4 1.0 1.0 1.0 1.4 1.0 1.0 1.0 4.7 1.0 1.0 1.4 2.1 1.3 1.0 1.0 3.6 1.8 1.0 1.7 1.0 5.4 1.7 1.0 1.0 ± (%) U Pb* 0.2358 0.1704 0.2544 0.2742 0.2565 0.1907 0.1070 0.2173 0.2458 0.3113 0.2387 0.0999 0.2797 0.1709 0.2669 0.2043 0.2155 0.3422 0.2139 0.3070 0.2480 0.3230 0.2545 0.3310 0.2147 0.2997 0.3445 0.2745 0.2920 0.2547 0.2594 0.2498 0.3154 0.0818 0.3520 0.1410 0.2935 0.1861 0.0665 0.0861 0.2618 0.2379 0.2087 0.1917 0.2553 238 206 1.4 2.3 4.7 2.4 1.5 2.8 2.2 1.5 1.4 1.8 2.1 2.6 1.4 2.2 7.3 2.2 2.3 2.2 1.4 1.6 2.5 1.4 3.2 2.0 2.0 1.4 1.8 2.5 4.8 3.2 1.7 2.6 2.4 1.7 1.6 2.9 3.8 2.6 1.7 2.1 1.6 6.1 1.9 1.9 1.9 ± (%) Isotope ratios Isotope U* Pb* 2.9178 1.7006 3.6897 3.6314 3.2314 2.0662 0.8962 2.4680 3.0611 4.5451 2.9324 0.8300 3.7919 1.7237 4.0125 2.2285 2.4334 5.4525 2.4329 4.4842 3.0177 4.9239 3.1483 5.0578 2.4207 4.4268 5.5143 3.7593 4.5403 3.1980 3.3093 3.0753 4.8262 0.6409 5.7625 1.2972 4.1145 1.9891 0.5037 0.6909 3.3963 3.7649 2.3180 2.0820 3.2214 235 207 1.2 1.0 2.1 2.5 2.1 1.1 2.5 1.9 1.2 1.0 1.0 1.5 1.9 1.0 2.0 6.8 1.9 2.1 1.0 1.0 1.3 2.1 1.0 3.0 1.8 1.5 1.0 1.5 2.3 1.1 3.1 1.4 2.2 1.0 1.3 2.7 1.3 1.9 1.4 1.3 1.3 2.9 1.0 1.6 1.6 ± (%) Pb* Pb* 9.0117 9.5061 9.4434 9.1721 8.6526 9.4395 9.0436 9.0226 9.3360 8.6147 8.8660 8.4232 9.8368 8.7138 206 207 11.1451 13.8176 10.4124 10.9445 12.7241 16.4681 12.1402 11.0736 17.5872 11.2215 16.5881 10.1719 13.6733 12.6407 12.2103 12.1205 11.3293 11.1436 12.2281 10.0679 10.9826 10.8089 11.2009 14.9917 12.9019 18.2059 17.1814 10.6289 12.4118 12.6979 10.9279 2.2 2.8 1.8 1.2 2.0 0.7 1.6 3.7 2.3 3.6 2.7 3.1 1.2 2.3 2.2 1.3 2.1 0.4 1.6 1.6 1.8 3.3 1.4 2.3 1.6 2.3 3.2 4.1 1.5 1.4 2.5 3.2 2.1 2.7 1.9 6.4 3.1 3.4 2.7 1.8 4.0 1.7 4.0 2.6 16.7 U/Th 9260 4328 5434 3274 6504 5898 9834 7852 8176 5000 2322 4732 4734 7818 3146 6582 9874 Pb Pb 20584 21374 17956 13794 32810 10600 15510 28214 20446 11060 12158 19970 32398 25656 25064 19108 15400 19026 23450 57368 41838 13830 13322 11984 14360 31360 30088 14614 206 204 79 76 27 60 59 57 60 60 50 72 88 29 200 173 305 148 391 439 279 118 211 174 167 218 180 328 187 257 175 122 158 298 191 195 114 352 360 168 502 108 291 138 105 465 154 U (ppm) Analysis VMN7-92 VMN7-91 VMN7-70 VMN7-69 VMN7-55 VMN7-90 VMN7-89 VMN7-88 VMN7-84 VMN7-83 VMN7-82 VMN7-77 VMN7-68 VMN7-54 VMN7-94 VMN7-87 VMN7-81 VMN7-80 VMN7-76 VMN7-67 VMN7-66 VMN7-63 VMN7-62 VMN7-61 VMN7-60 VMN7-59 VMN7-58 VMN7-57 VMN7-51 VMN7-52 VMN7-50 VMN7-93 VMN7-86 VMN7-79 VMN7-78 VMN7-75 VMN7-74 VMN7-73 VMN7-72 VMN7-71 VMN7-65 VMN7-64 VMN7-49 VMN7-48 VMN7-47

Geologica Acta, 9(3-4), 265-272 (2011) III DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 8.5 6.1 8.7 8.7 8.4 9.3 8.7 9.3 8.7 61.4 19.8 27.3 35.7 18.6 32.0 29.7 81.0 77.2 44.1 20.3 18.1 24.7 17.3 32.4 18.2 38.0 35.2 44.0 25.6 30.4 30.3 32.6 18.5 10.8 32.0 37.3 20.5 36.8 36.2 34.9 20.0 19.1 20.1 17.9 18.2 ± (Ma) 998.0 910.2 594.9 935.3 934.5 987.5 938.0 897.6 968.3 961.5 999.8 938.4 952.8 936.9 1533.3 1131.2 1114.4 1609.8 1024.9 1239.8 1483.1 1378.1 1033.5 1023.5 1901.8 1810.4 1622.2 1812.4 1000.4 1179.3 1168.8 1772.4 1429.2 1008.2 1671.7 1038.3 1796.4 1813.3 1516.3 1115.7 1586.2 1449.0 1115.0 2126.5 1815.6 (Ma) Best Best age 61.4 28.5 19.8 27.3 35.7 18.6 32.0 29.7 81.0 77.2 31.1 44.1 20.3 18.1 24.7 56.5 32.4 18.2 38.0 35.2 44.0 25.6 30.4 30.3 35.4 32.6 20.6 27.1 18.5 32.0 37.3 23.0 20.5 36.8 41.9 36.2 35.5 34.9 20.0 19.1 20.1 17.9 25.9 18.2 ± 135.9 (Ma) Pb* Pb* 998.0 946.9 529.3 922.3 987.5 957.6 918.5 941.3 956.3 999.8 980.0 984.7 988.0 1533.3 1131.2 1114.4 1609.8 1024.9 1239.8 1483.1 1378.1 1033.5 1023.5 1901.8 1810.4 1000.4 1622.2 1812.4 1000.4 1179.3 1168.8 1772.4 1429.2 1008.2 1671.7 1038.3 1796.4 1813.3 1516.3 1115.7 1586.2 1449.0 1115.0 2126.5 1815.6 206 207 8.5 8.9 9.5 9.5 20.6 11.3 10.4 15.8 13.3 11.4 27.9 11.9 14.5 45.5 55.6 11.1 15.4 13.9 14.2 21.2 17.1 11.9 14.0 14.2 20.5 14.4 14.4 11.2 12.3 12.0 43.6 11.1 13.9 19.2 12.7 13.0 23.0 14.1 12.7 13.5 28.2 14.5 12.4 10.0 11.7 ± (Ma) U Pb* 921.0 581.5 999.1 931.5 954.3 994.0 970.5 943.9 903.7 960.1 975.7 993.7 959.9 977.0 950.9 962.5 952.3 1027.5 1488.5 1118.9 1039.0 1609.5 1188.4 1334.5 1204.2 1019.0 1851.5 1778.5 1603.6 1808.1 1175.7 1056.5 1760.5 1427.2 1001.4 1496.6 1785.2 1795.6 1254.9 1093.4 1512.5 1387.2 1088.2 1980.3 1725.5 235 207 Apparent ages (Ma) ages Apparent 8.5 9.6 6.1 9.2 8.7 9.3 8.9 8.7 8.4 9.4 8.9 9.3 9.2 9.0 8.7 9.3 8.7 9.9 13.0 19.3 14.2 15.1 49.5 69.0 20.2 15.3 17.3 17.2 15.7 10.7 10.7 20.4 15.3 12.8 67.9 10.8 13.7 15.5 15.6 26.0 10.0 44.7 19.9 16.0 14.6 ± (Ma) U* Pb* 910.2 594.9 987.3 935.3 934.5 991.1 963.0 938.0 897.6 968.3 954.6 973.6 961.5 998.2 967.0 938.4 952.8 936.9 1041.4 1457.3 1112.5 1003.4 1609.3 1160.3 1243.8 1109.6 1012.3 1807.0 1751.5 1589.5 1804.4 1173.7 1003.0 1750.5 1425.9 1376.1 1775.7 1780.3 1108.2 1082.2 1460.5 1347.3 1074.8 1843.4 1652.2 238 206 0.31 0.69 0.58 0.81 0.49 0.71 0.17 0.53 0.68 0.72 0.86 0.55 0.42 0.79 0.59 0.58 0.57 0.71 0.53 0.49 0.70 0.58 0.53 0.56 0.50 0.71 0.98 0.67 0.71 0.69 0.44 0.66 0.68 0.53 0.48 0.80 0.44 0.52 0.50 0.95 0.85 0.70 0.70 0.62 0.71 corr. error 1.0 1.0 1.0 1.9 1.0 1.0 1.1 1.0 1.4 4.4 6.8 1.0 1.0 1.3 1.0 2.0 1.2 1.0 1.2 1.0 2.2 1.0 1.0 1.0 1.0 1.0 5.5 1.2 1.0 1.5 1.0 1.0 1.0 1.0 1.0 2.6 1.0 1.1 1.0 3.4 1.6 1.0 1.0 1.0 1.0 ± (%) U Pb* 0.1753 0.2537 0.1516 0.1884 0.1684 0.2836 0.0967 0.1655 0.1972 0.2128 0.1878 0.1561 0.1700 0.3236 0.3122 0.1560 0.2796 0.3230 0.1662 0.1997 0.1683 0.3120 0.2476 0.1611 0.1566 0.1494 0.2380 0.1621 0.1596 0.1630 0.3171 0.3181 0.1608 0.1675 0.1618 0.1876 0.1567 0.1593 0.1828 0.2543 0.2324 0.1814 0.3310 0.1564 0.2921 238 206 3.2 1.5 1.7 2.3 2.0 1.4 6.3 1.9 2.1 6.1 7.9 1.8 2.4 1.6 1.7 3.4 2.1 1.4 2.2 2.0 3.1 1.7 1.9 1.8 2.0 1.4 5.6 1.8 1.4 2.2 2.3 1.5 1.5 1.9 2.1 3.2 2.3 2.0 2.0 3.6 1.9 1.4 1.4 1.6 1.4 ± (%) Isotope ratios Isotope U* Pb* 1.7509 3.3317 1.4769 2.0100 1.7821 3.8798 0.7730 1.6749 2.2232 2.7221 2.2737 1.5027 1.7280 5.1933 4.7638 1.5596 3.8515 4.9341 1.6616 2.1831 1.8306 4.6623 3.0780 1.6007 1.5335 1.4351 3.3663 1.5741 1.6141 1.6608 4.8017 4.8612 1.5738 1.6810 1.6176 2.4416 1.5510 1.5803 1.9354 3.4354 2.9202 1.9202 6.0310 1.5545 4.4705 235 207 1.0 3.0 1.1 1.4 1.4 1.8 1.0 6.2 1.6 1.5 4.3 4.0 1.5 2.2 1.0 1.4 2.8 1.7 1.0 1.9 1.8 2.2 1.4 1.6 1.5 1.7 1.0 1.0 1.3 1.6 2.1 1.1 1.1 1.6 1.8 1.9 2.1 1.7 1.8 1.1 1.0 1.0 1.0 1.3 1.0 ± (%) Pb* Pb* 8.5901 9.0361 9.0263 9.2266 9.7466 9.1060 9.0216 7.5682 9.0103 206 207 13.6340 13.8067 10.4973 14.1570 12.9217 13.0309 10.0772 17.2447 13.5344 13.6246 12.2305 10.7799 11.3894 14.3276 13.5666 13.7906 10.0103 13.7905 12.6124 12.6796 11.0896 13.8778 14.0828 14.3542 14.1958 14.0921 13.7377 13.7947 10.5920 13.9292 13.8972 13.0226 10.2054 10.9750 13.0275 13.8750 3.6 3.4 1.5 2.3 1.4 3.9 1.6 1.6 3.6 3.1 1.5 1.8 1.9 2.2 3.2 0.7 1.3 2.9 1.9 2.3 1.8 1.2 2.5 3.2 1.6 1.8 2.7 2.4 1.2 1.9 3.1 1.5 3.9 4.2 2.5 1.8 1.8 2.2 3.1 2.9 2.6 4.0 1.9 4.7 4.8 U/Th 6850 9022 8440 2046 4536 4762 7778 9836 Pb Pb 14404 21734 12042 25318 17966 15658 19552 41946 18390 11062 13366 10216 21160 17714 11852 19212 27674 14772 12812 13992 12136 10458 14056 22858 25412 14464 18502 33500 13404 11214 22328 46768 14188 14778 26020 16444 19972 206 204 78 90 42 54 85 50 82 325 144 176 235 190 191 175 166 371 105 195 154 241 146 114 106 130 182 354 147 116 130 106 185 256 148 171 220 668 100 120 212 420 149 142 260 200 249 U (ppm) Analysis VMN16-39 VMN16-9 VMN16-8 VMN16-38 VMN16-37 VMN16-36 VMN16-32 VMN16-31 VMN16-30 VMN16-29 VMN16-7 VMN16-41 VMN16-40 VMN16-35 VMN16-34 VMN16-28 VMN16-26 VMN16-24 VMN16-23 VMN16-22 VMN16-21 VMN16-20 VMN16-17 VMN16-16 VMN16-14 VMN16-13 VMN16-6 VMN16-5 VMN16-4 VMN16-33 VMN16-25 VMN16-19 VMN16-18 VMN16-12 VMN16-11 VMN16-10 VMN16-3 VMN16-2 VMN16-1 VMN7-100 VMN7-99 VMN7-98 VMN7-97 VMN7-95 VMN7-96

Geologica Acta, 9(3-4), 265-272 (2011) IV DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 6.1 8.4 8.5 9.0 8.3 8.9 4.4 9.0 8.6 30.9 42.3 51.3 25.0 43.3 27.7 25.5 27.6 28.0 18.7 16.6 23.8 25.3 19.6 50.0 26.9 53.0 23.7 28.4 89.3 23.8 17.8 26.1 19.0 25.9 33.8 10.6 12.3 25.8 10.1 50.5 23.6 35.2 25.5 41.2 50.2 ± (Ma) 635.9 896.0 913.0 885.9 965.8 964.2 894.0 958.5 451.4 962.9 881.3 973.4 650.0 923.8 999.2 1043.1 1516.0 1051.3 1159.5 1388.9 1563.7 1030.5 1009.1 1577.2 1888.6 1201.1 1535.9 1491.8 1028.5 1766.1 1387.1 1241.9 1082.0 1816.9 2004.9 1323.9 1486.3 1139.2 1000.6 1536.3 1026.5 1832.8 1042.6 1214.3 1109.3 (Ma) Best Best age 30.9 42.3 39.6 51.3 59.9 25.0 43.3 61.1 65.9 25.5 27.6 28.0 18.7 67.7 23.8 25.3 39.0 19.6 50.0 26.9 53.0 23.7 28.4 89.3 23.8 17.8 26.1 19.0 36.0 25.9 52.3 45.8 33.8 25.5 60.1 78.0 28.4 25.8 50.5 23.6 27.7 35.2 25.5 41.2 50.2 ± (Ma) Pb* Pb* 616.0 921.4 938.6 860.9 965.0 930.9 918.4 922.7 477.0 968.1 982.6 960.8 667.1 939.9 999.2 1043.1 1516.0 1051.3 1159.5 1388.9 1563.7 1030.5 1009.1 1577.2 1888.6 1201.1 1535.9 1491.8 1028.5 1766.1 1387.1 1241.9 1082.0 1816.9 2004.9 1323.9 1486.3 1139.2 1000.6 1536.3 1026.5 1832.8 1042.6 1214.3 1109.3 206 207 9.8 8.4 11.8 19.4 17.6 11.1 18.4 20.7 19.0 27.2 68.8 11.6 12.6 20.4 23.6 16.5 11.4 11.4 13.3 21.4 10.5 25.4 22.2 36.4 29.8 14.6 19.3 12.4 11.1 13.9 12.1 16.9 13.0 10.7 19.9 24.6 24.1 10.1 24.8 18.7 13.1 10.2 12.2 15.4 16.9 ± (Ma) U Pb* 631.5 903.4 920.5 878.8 999.8 965.6 954.1 989.8 901.1 947.7 455.7 970.4 964.5 910.7 969.5 653.9 995.1 928.6 996.2 1025.5 1520.6 1019.3 1156.3 1374.5 1394.9 1026.0 1568.0 1825.0 1196.8 1532.4 1394.2 1720.0 1323.5 1198.7 1014.2 1744.3 1980.3 1329.1 1495.0 1118.1 1511.0 1728.7 1045.1 1201.4 1096.7 235 207 Apparent ages (Ma) ages Apparent 9.4 6.1 8.4 8.5 9.3 9.0 9.0 8.3 8.9 4.4 9.0 8.6 9.2 9.7 13.6 10.6 19.3 27.7 11.0 13.1 32.6 16.6 22.1 10.9 13.6 12.0 14.8 31.9 53.3 11.9 17.3 33.4 12.0 13.4 16.2 11.0 10.6 12.3 36.5 10.1 27.4 26.7 12.6 10.0 ± 104.4 (Ma) U* Pb* 635.9 896.0 913.0 885.9 995.5 965.8 964.2 972.4 983.1 894.0 958.5 451.4 957.1 962.9 881.3 973.4 650.0 980.9 923.8 994.9 1017.3 1523.8 1004.5 1154.6 1365.3 1287.1 1023.9 1561.2 1769.9 1194.4 1529.9 1331.3 1682.3 1284.5 1174.8 1684.3 1956.9 1332.4 1501.2 1107.3 1493.0 1643.9 1046.3 1194.3 1090.3 238 206 0.55 0.41 0.48 0.37 0.62 0.32 0.57 0.32 0.73 0.99 0.65 0.72 0.92 0.49 0.73 0.61 0.69 0.47 0.35 0.60 0.33 0.91 0.96 0.28 0.67 0.89 0.60 0.71 0.77 0.50 0.37 0.44 0.60 0.69 0.45 0.25 0.89 0.78 0.77 0.82 0.50 0.60 0.67 0.44 0.38 corr. error 1.0 1.0 1.0 1.0 1.0 1.0 1.6 1.0 3.4 9.0 1.2 1.4 2.4 1.9 1.4 1.0 1.0 1.0 1.0 1.0 1.0 2.7 5.0 1.3 1.2 2.0 1.0 1.0 1.6 1.0 1.0 1.0 1.2 1.2 1.5 1.0 2.7 1.6 3.0 1.8 1.0 1.0 1.2 1.0 1.0 ± (%) U Pb* 0.1709 0.2667 0.1037 0.1686 0.1961 0.1491 0.2359 0.1522 0.1473 0.2210 0.1721 0.1670 0.2740 0.1616 0.3159 0.2036 0.2679 0.1613 0.2294 0.1628 0.2982 0.2205 0.1999 0.1647 0.2986 0.3547 0.2296 0.2622 0.1874 0.1488 0.1603 0.0725 0.1601 0.1611 0.1465 0.1630 0.2606 0.1061 0.1643 0.2905 0.1762 0.1541 0.2035 0.1843 0.1669 238 206 1.8 2.5 2.1 2.7 1.6 3.1 2.7 3.1 4.6 9.1 1.8 2.0 2.6 3.8 1.9 1.6 1.4 2.1 2.8 1.7 3.1 3.0 5.2 4.6 1.8 2.2 1.7 1.4 2.1 2.0 2.7 2.3 2.1 1.7 3.3 3.9 3.1 2.1 3.9 2.3 2.0 1.7 1.7 2.3 2.7 ± (%) Isotope ratios Isotope U* Pb* 1.7455 3.4707 0.8626 1.7289 2.1230 1.4344 2.8717 1.4759 1.3761 2.9501 1.7469 1.6768 3.6845 1.5881 5.0338 2.2500 3.5232 1.5591 2.9477 1.6506 4.4409 2.6819 2.2560 1.7151 4.5725 6.0310 2.7025 3.3596 2.0077 1.4289 1.5431 0.5664 1.6004 1.5853 1.4520 1.5982 3.4286 0.9040 1.6645 4.4875 1.7990 1.4956 2.2649 1.9449 1.6675 235 207 1.5 2.2 1.8 2.5 1.3 2.9 2.3 3.0 3.2 1.4 1.4 1.4 1.0 3.3 1.3 1.3 1.0 1.9 2.6 1.3 2.9 1.2 1.3 1.5 4.5 1.3 1.0 1.3 1.0 1.3 1.8 2.5 2.1 1.7 1.3 2.9 3.8 1.4 1.3 2.5 1.7 1.4 1.3 2.1 2.5 ± (%) Pb* Pb* 8.6538 9.2582 8.9249 9.0038 8.1085 206 207 13.5025 10.5936 16.5708 13.4479 12.7392 14.3340 11.3254 14.2147 14.7601 12.3908 10.3286 13.5871 13.7312 10.2545 14.0321 12.4737 10.4828 14.2681 10.7303 13.6003 11.3360 12.2173 13.2436 11.7139 10.7619 12.8701 14.3549 14.3248 17.6593 13.7893 14.0108 13.9116 14.0613 10.4805 16.1816 13.6139 13.5058 14.2053 13.0644 13.7987 3.1 0.6 0.5 2.1 1.3 2.2 4.5 3.0 2.7 1.9 2.3 3.3 4.5 2.2 2.2 1.8 2.9 5.8 3.5 2.8 6.0 1.3 2.5 2.1 3.5 2.6 1.6 1.4 1.9 2.6 3.4 2.6 3.0 2.2 1.6 2.7 3.0 6.9 3.2 1.1 2.7 1.5 2.9 2.1 1.8 U/Th 3816 9946 8136 3244 3832 9552 8592 5554 6994 6512 Pb Pb 11832 18810 14096 11326 21696 11638 11432 14506 11058 13544 29694 15716 72538 10706 14824 33106 12402 10618 20484 20774 10292 15106 10706 26438 21176 12202 14112 10184 14620 15828 13598 19896 10452 19580 53290 206 204 33 84 83 38 42 93 90 64 80 67 94 66 71 148 200 263 208 110 228 270 123 117 122 229 113 109 464 100 359 130 268 181 117 284 174 144 193 324 171 166 170 200 295 746 136 U (ppm) Analysis VMN16-65 VMN16-64 VMN16-63 VMN16-62 VMN16-57 VMN16-56 VMN16-55 VMN16-50 VMN16-79 VMN16-78 VMN16-77 VMN16-76 VMN16-75 VMN16-61 VMN16-60 VMN16-54 VMN16-53 VMN16-52 VMN16-49 VMN16-48 VMN17-3 VMN17-1 VMN16-85 VMN16-84 VMN16-83 VMN16-74 VMN16-72 VMN16-71 VMN16-70 VMN16-69 VMN16-67 VMN16-68 VMN16-58 VMN16-51 VMN16-47 VMN16-46 VMN16-45 VMN16-44 VMN17-2 VMN16-82 VMN16-81 VMN16-80 VMN16-73 VMN16-66 VMN16-43

Geologica Acta, 9(3-4), 265-272 (2011) V DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 9.2 7.9 9.1 8.7 8.9 8.6 8.6 9.0 59.8 19.1 57.1 38.3 22.5 39.8 21.0 24.5 26.9 29.3 32.0 21.2 46.2 10.3 28.0 33.6 34.4 25.5 33.9 27.1 19.7 28.2 14.8 37.8 22.8 27.4 27.9 37.6 33.4 37.3 18.8 23.5 20.3 29.0 33.3 38.7 31.7 ± (Ma) 971.9 947.7 618.5 904.1 972.9 994.1 957.1 938.2 959.2 613.9 951.0 914.7 939.5 970.8 944.2 923.3 921.3 964.7 993.4 1004.1 1462.7 1031.3 1208.3 1463.7 1511.4 1009.2 1008.0 1144.8 1010.2 1000.7 1822.8 1194.6 1020.9 1801.2 1010.5 1019.1 1180.6 1082.7 1301.9 1526.9 1030.2 1026.2 1342.8 1470.6 1222.5 (Ma) Best Best age 59.8 19.1 57.1 38.3 34.0 21.8 22.5 39.8 37.4 77.3 24.5 44.2 29.3 32.0 21.2 46.2 81.0 28.0 33.6 34.4 25.5 33.9 35.5 38.0 19.7 43.9 37.8 22.8 61.5 27.9 82.1 37.6 33.4 75.2 37.3 59.1 18.8 43.5 73.5 23.5 20.3 29.0 33.3 38.7 31.7 ± (Ma) Pb* Pb* 971.9 927.3 637.2 927.1 994.1 954.5 917.4 949.5 842.6 943.7 872.8 930.1 970.8 962.4 950.6 933.5 961.1 993.4 1004.1 1462.7 1031.3 1208.3 1463.7 1002.0 1511.4 1009.2 1008.0 1144.8 1010.2 1000.7 1822.8 1194.6 1020.9 1801.2 1010.5 1019.1 1180.6 1082.7 1301.9 1526.9 1030.2 1026.2 1342.8 1470.6 1222.5 206 207 7.8 19.8 16.2 19.6 13.9 12.0 12.3 43.9 18.9 24.2 13.0 23.0 14.2 11.7 11.7 17.4 25.1 14.5 23.4 18.7 12.7 12.5 21.7 25.1 31.5 16.7 21.5 16.3 26.1 19.3 25.2 15.1 17.9 23.6 16.0 18.6 12.3 14.2 23.2 11.7 13.0 14.2 14.3 17.5 17.4 ± (Ma) U Pb* 998.3 973.1 941.6 622.6 933.0 959.0 972.7 956.3 980.7 963.4 932.0 992.5 956.3 665.1 948.8 993.0 902.5 936.7 978.5 949.7 931.4 924.9 963.6 990.4 978.3 968.4 1423.6 1050.8 1207.4 1412.3 1445.4 1148.3 1002.2 1793.8 1096.1 1005.2 1758.7 1013.7 1161.8 1038.7 1289.6 1512.3 1253.5 1436.8 1154.9 235 207 Apparent ages (Ma) ages Apparent 9.2 9.2 7.9 9.8 9.1 9.0 9.2 8.7 8.9 8.6 8.6 9.0 23.5 10.6 14.5 66.5 21.0 15.1 26.9 12.6 13.8 10.5 10.3 16.6 30.5 17.8 13.4 27.1 28.2 54.6 14.8 26.1 21.0 27.4 25.3 14.1 20.6 12.1 16.1 13.2 16.1 15.5 11.0 12.7 19.9 ± (Ma) U* Pb* 995.7 973.6 947.7 618.5 904.1 972.9 963.3 957.1 968.0 944.0 938.2 984.6 959.2 613.9 951.0 981.2 914.7 998.0 939.5 981.9 944.2 923.3 921.3 964.7 989.0 955.3 943.2 1397.6 1060.2 1206.9 1378.4 1401.0 1150.2 1002.9 1769.1 1047.2 1723.0 1015.2 1151.7 1017.9 1282.2 1501.9 1202.2 1414.0 1119.2 238 206 0.32 0.88 0.33 0.53 0.53 0.80 0.76 0.93 0.80 0.26 0.81 0.81 0.54 0.54 0.83 0.39 0.29 0.80 0.89 0.52 0.73 0.87 0.94 0.96 0.61 0.83 0.90 0.73 0.86 0.51 0.24 0.64 0.80 0.26 0.48 0.33 0.77 0.43 0.27 0.78 0.87 0.78 0.50 0.44 0.77 corr. error 1.0 1.9 1.0 1.2 1.0 1.3 1.3 5.4 2.5 1.0 1.7 3.0 1.0 1.0 1.6 1.0 1.2 1.8 3.3 1.2 1.4 3.0 4.8 3.6 1.7 2.8 2.3 3.2 2.4 1.0 1.0 1.6 2.2 1.0 1.0 1.0 1.2 1.0 1.0 1.4 1.8 1.8 1.0 1.0 1.9 ± (%) U Pb* 0.1670 0.2421 0.1788 0.1630 0.1584 0.1007 0.2059 0.2384 0.1506 0.1629 0.1612 0.1601 0.2428 0.1620 0.1577 0.1953 0.1567 0.1650 0.1683 0.3158 0.1764 0.1604 0.0999 0.3064 0.1590 0.1706 0.1644 0.1525 0.1956 0.1674 0.1569 0.1645 0.1710 0.1577 0.2201 0.1540 0.2624 0.1536 0.1614 0.1658 0.1597 0.1576 0.2050 0.2453 0.1896 238 206 3.1 2.1 3.0 2.2 2.0 1.7 1.7 5.8 3.1 3.9 2.1 3.7 1.8 1.9 1.9 2.5 4.1 2.3 3.7 2.2 1.9 3.5 5.1 3.8 2.7 3.3 2.6 4.4 2.8 2.0 4.1 2.4 2.7 3.8 2.2 3.1 1.6 2.3 3.7 1.8 2.1 2.3 2.0 2.3 2.5 ± (%) Isotope ratios Isotope U* Pb* 1.6729 3.0634 1.8148 1.6074 1.5277 0.8462 2.2843 3.0184 1.5065 1.5713 1.6065 1.5647 3.1518 1.6271 1.5827 2.0986 1.5041 1.6578 1.6832 4.8513 1.9433 1.5645 0.9252 4.6520 1.5457 1.7139 1.6590 1.4323 2.1399 1.6911 1.5156 1.6213 1.7813 1.5480 2.5610 1.5025 3.4345 1.4866 1.5831 1.6522 1.6208 1.5955 2.4368 3.1165 2.1186 235 207 2.9 1.0 2.8 1.9 1.7 1.0 1.1 2.1 1.8 3.8 1.2 2.2 1.0 1.6 1.6 1.0 2.3 3.9 1.4 1.7 1.9 1.3 1.7 1.8 1.1 2.1 1.9 1.1 3.0 1.4 1.7 4.0 1.8 1.7 3.7 1.9 2.9 1.0 2.1 3.6 1.2 1.4 1.7 2.0 1.6 ± (%) Pb* Pb* 8.9747 9.0818 206 207 13.7654 13.2395 10.8966 13.5818 13.9847 14.2932 16.4087 12.4280 10.8904 13.7796 14.2944 13.8334 14.1047 13.5888 10.6199 13.7303 13.7389 12.8341 14.3618 13.7242 13.7884 12.5151 14.1391 14.8904 14.1789 13.7219 13.6640 14.6758 12.6042 13.6516 14.2737 13.9921 14.0503 11.8474 14.1313 10.5330 14.2498 14.0587 13.8381 13.6160 11.5998 10.8512 12.3387 1.7 2.6 4.8 3.7 3.1 2.0 2.4 3.2 3.9 0.8 3.4 1.9 2.5 1.1 4.4 5.4 4.6 2.4 3.0 2.7 4.8 1.6 1.7 2.9 1.3 1.4 2.2 2.8 2.4 2.8 3.0 2.2 2.2 2.3 1.5 3.9 2.6 1.4 2.4 2.8 0.8 3.1 2.4 3.0 10.0 U/Th 8192 4030 4938 4450 7538 8780 5010 6834 3282 5276 7672 4724 6900 8120 7754 4964 4550 7374 9514 3608 7008 3518 7650 5846 Pb Pb 25380 14724 10646 17798 13228 23774 48046 15320 10276 20716 18072 14818 12654 14750 15490 63186 10246 16782 18426 17762 24778 206 204 64 46 53 98 46 83 46 42 84 38 68 94 48 67 48 97 49 54 85 96 44 85 82 77 238 297 145 173 141 142 312 253 101 239 193 272 166 179 112 519 127 184 166 142 274 U (ppm) Analysis VMN17-25 VMN17-39 VMN17-32 VMN17-24 VMN17-46 VMN17-45 VMN17-44 VMN17-38 VMN17-31 VMN17-23 VMN17-18 VMN17-17 VMN17-43 VMN17-42 VMN17-37 VMN17-36 VMN17-35 VMN17-30 VMN17-29 VMN17-22 VMN17-16 VMN17-15 VMN17-11 VMN17-9 VMN17-10 VMN17-41 VMN17-34 VMN17-28 VMN17-27 VMN17-21 VMN17-8 VMN17-40 VMN17-33 VMN17-26 VMN17-20 VMN17-19 VMN17-14 VMN17-7 VMN17-48 VMN17-47 VMN17-13 VMN17-12 VMN17-6 VMN17-5 VMN17-4

Geologica Acta, 9(3-4), 265-272 (2011) VI DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 8.5 8.9 8.4 23.1 38.7 37.8 42.0 35.3 27.4 50.9 28.2 53.1 29.1 39.4 37.3 24.1 31.1 23.4 30.1 49.2 21.4 18.2 32.9 36.2 58.9 34.3 40.3 17.5 73.4 32.7 30.8 22.7 25.0 74.9 20.9 19.6 38.4 70.6 23.0 32.8 31.9 18.7 22.9 37.1 44.4 ± (Ma) 986.5 956.7 988.8 907.1 953.4 996.5 976.3 998.3 972.4 908.7 989.1 998.5 978.0 868.4 904.4 902.3 993.0 1522.2 1413.6 1021.5 2151.2 1167.3 1480.6 1175.5 1424.2 1638.4 1030.0 1054.7 1339.4 1333.5 1008.3 1791.8 1011.5 1024.3 1040.2 1737.1 1542.4 1163.9 1380.2 1210.4 1749.7 1365.1 1604.5 1260.0 1016.3 (Ma) Best Best age 23.1 38.7 37.8 42.0 35.3 27.4 50.9 28.2 53.1 66.5 29.1 39.4 37.3 24.1 52.2 31.1 30.1 23.4 49.2 21.4 18.2 36.2 32.9 58.9 34.3 40.3 20.5 73.4 32.7 30.8 20.7 33.1 25.0 74.9 20.7 20.9 38.4 70.6 23.0 32.8 31.9 18.7 22.9 44.4 37.1 ± (Ma) Pb* Pb* 986.5 956.7 988.8 892.2 928.5 996.5 976.3 998.3 972.4 934.2 989.1 998.5 978.0 918.0 942.5 938.9 993.0 1522.2 1413.6 1021.5 2151.2 1167.3 1480.6 1175.5 1424.2 1638.4 1030.0 1054.7 1339.4 1333.5 1008.3 1791.8 1011.5 1024.3 1040.2 1737.1 1542.4 1163.9 1380.2 1210.4 1749.7 1365.1 1604.5 1260.0 1016.3 206 207 9.1 17.9 31.6 13.4 26.7 24.6 11.8 21.3 11.8 24.4 20.2 31.0 17.4 18.4 10.5 16.8 13.4 17.0 12.4 22.9 11.9 12.2 12.8 19.8 13.8 14.3 13.8 25.5 16.2 14.3 17.5 11.5 16.9 36.3 13.6 15.3 23.7 28.9 11.0 18.1 14.5 14.5 10.5 18.8 22.8 ± (Ma) U Pb* 994.7 984.5 986.1 973.8 902.8 945.9 992.0 975.3 973.2 916.1 989.7 972.9 882.5 964.4 915.5 913.0 980.9 1487.7 1268.1 1922.2 1154.5 1483.8 1020.4 1406.2 1659.7 1021.0 1048.2 1328.0 1340.8 1771.6 1009.2 1025.3 1012.2 1003.9 1044.4 1688.1 1529.4 1134.1 1394.3 1128.3 1708.3 1354.1 1603.5 1006.4 1007.6 235 207 Apparent ages (Ma) ages Apparent 9.1 8.5 8.9 9.0 8.8 8.4 9.3 9.6 9.6 25.4 41.9 33.8 30.5 10.5 21.1 11.4 18.6 40.4 12.5 14.8 10.5 12.9 23.3 11.8 21.0 15.4 12.3 10.4 17.5 16.5 18.4 15.5 22.7 21.9 24.3 17.9 19.6 29.6 12.6 11.1 18.6 12.2 21.3 21.2 26.6 ± (Ma) U* Pb* 982.6 983.6 999.4 967.2 907.1 949.6 953.4 989.9 974.8 973.6 908.7 990.0 970.7 868.4 945.3 904.4 902.3 965.1 894.0 1463.6 1184.1 1717.1 1147.8 1486.0 1394.4 1676.5 1016.8 1045.0 1320.9 1345.4 1754.6 1008.2 1038.0 1006.6 1006.4 1046.4 1648.8 1519.9 1118.6 1403.5 1086.2 1674.6 1347.1 1602.7 1014.4 238 206 0.85 0.89 0.47 0.87 0.71 0.59 0.68 0.68 0.45 0.30 0.95 0.44 0.45 0.68 0.37 0.66 0.85 0.66 0.56 0.71 0.53 0.49 0.33 0.61 0.50 0.90 0.45 0.77 0.75 0.94 0.69 0.53 0.88 0.38 0.76 0.92 0.83 0.26 0.69 0.58 0.52 0.83 0.79 0.79 0.70 corr. error 1.9 3.9 1.0 3.7 2.0 1.0 2.3 1.3 1.4 1.0 4.6 1.0 1.0 1.1 1.0 1.3 2.0 1.3 1.7 1.0 1.0 1.0 1.0 1.3 1.2 2.1 1.8 2.0 1.7 2.8 1.0 1.0 2.3 1.7 1.3 2.3 2.9 1.0 1.1 1.3 1.0 1.5 2.4 2.8 1.2 ± (%) U Pb* 0.2549 0.2016 0.1647 0.1648 0.3052 0.1949 0.1677 0.1619 0.2593 0.1511 0.1587 0.2415 0.2970 0.1709 0.1594 0.1760 0.2274 0.1660 0.2321 0.3128 0.1693 0.1633 0.1747 0.1690 0.1630 0.1514 0.1660 0.1690 0.1625 0.1442 0.1579 0.1506 0.1762 0.2915 0.2659 0.1502 0.1895 0.2432 0.1835 0.2966 0.2324 0.2823 0.1615 0.1704 0.1488 238 206 2.3 4.4 2.1 4.2 2.9 1.7 3.4 1.9 3.1 3.4 4.8 2.3 2.2 1.6 2.7 2.0 2.3 2.0 3.1 1.4 1.9 2.0 3.1 2.1 2.3 2.3 4.0 2.5 2.3 3.0 1.5 1.9 2.6 4.4 1.7 2.5 3.5 3.8 1.6 2.2 1.9 1.8 3.0 3.6 1.6 ± (%) Isotope ratios Isotope U* Pb* 3.3282 2.4865 1.6635 1.6368 5.6396 2.1176 1.6411 1.6092 3.3116 1.4330 1.7318 2.9946 4.1270 1.7334 1.5385 1.8075 2.6982 1.6563 2.7453 4.7247 1.7019 1.6131 1.7450 1.7099 1.6077 1.4652 1.6505 1.6878 1.6070 1.3848 1.5853 1.4637 1.7970 4.2724 3.5095 1.4575 2.0555 2.9479 2.0381 4.3783 2.7946 3.8511 1.6274 1.6976 1.6943 235 207 1.2 2.0 1.9 2.1 2.2 2.0 1.4 2.5 1.4 2.8 3.2 1.5 2.1 2.0 1.2 2.5 1.5 1.2 1.5 2.5 1.0 1.6 1.8 2.9 1.7 2.0 1.0 3.6 1.6 1.5 1.0 1.1 1.6 1.2 4.1 1.1 1.0 1.9 3.7 1.2 1.8 1.7 1.0 1.8 1.2 ± (%) Pb* Pb* 7.4621 9.9234 9.1289 9.4063 9.3416 206 207 14.3576 10.5591 11.1807 13.6475 13.8852 13.8406 12.6893 14.0894 13.8695 10.7941 14.5388 12.6367 11.1185 13.5906 14.2849 13.4252 11.6206 13.8168 11.6559 13.7149 13.9543 13.8044 13.6284 13.9815 14.2449 13.8669 13.8029 13.9427 13.7366 14.1875 13.5219 10.4462 14.2124 12.7108 11.3769 12.4151 11.4667 10.1057 13.6829 12.1049 1.2 1.3 2.6 3.2 6.5 3.0 2.6 2.1 3.2 2.8 3.1 1.2 1.4 6.6 1.9 2.0 4.6 2.7 2.4 0.9 3.1 1.3 1.1 3.8 3.3 2.0 3.0 3.2 2.0 1.6 4.0 2.5 2.5 3.2 2.0 1.5 1.7 3.9 1.9 5.4 1.7 1.6 2.1 3.7 2.1 U/Th 7862 3956 9742 4068 9514 5058 4402 8190 7828 5716 8440 9514 3622 6854 3744 9750 8652 3530 Pb Pb 14324 13610 16582 21802 11792 11350 25322 13940 19684 15866 20486 10116 13398 11128 12952 28072 11526 21646 22494 18144 16236 33630 18880 14754 19700 11276 13742 206 204 37 79 85 81 48 96 56 51 72 85 75 68 66 60 40 76 43 30 161 186 245 106 109 192 462 205 179 170 107 155 134 149 336 111 212 174 131 241 341 138 101 148 106 105 218 U (ppm) Analysis VMN17-85 VMN17-78 VMN17-77 VMN17-76 VMN17-92 VMN17-84 VMN17-83 VMN17-75 VMN17-63 VMN17-91 VMN17-82 VMN17-81 VMN17-74 VMN17-62 VMN17-61 VMN17-60 VMN17-90 VMN17-89 VMN17-88 VMN17-80 VMN17-73 VMN17-71 VMN17-70 VMN17-69 VMN17-59 VMN17-58 VMN17-56 VMN17-55 VMN17-87 VMN17-86 VMN17-79 VMN17-72 VMN17-67 VMN17-66 VMN17-65 VMN17-64 VMN17-57 VMN17-54 VMN17-53 VMN17-52 VMN17-51 VMN17-50 VMN17-94 VMN17-93 VMN17-49

Geologica Acta, 9(3-4), 265-272 (2011) VII DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 4.8 6.7 23.1 31.7 37.7 31.0 29.2 23.0 24.0 35.4 91.2 26.3 17.9 17.8 39.4 30.5 39.3 19.2 50.0 32.3 52.6 18.3 25.6 19.9 22.9 30.7 21.9 46.6 59.0 32.7 90.9 28.3 35.9 18.1 18.7 37.8 22.5 42.5 23.1 65.1 46.3 25.8 25.5 42.3 22.5 ± (Ma) 502.4 491.1 1999.8 1847.6 1836.0 2123.9 1800.8 1494.9 1815.7 1813.8 1493.0 1828.8 1926.7 1988.5 1460.4 2021.1 1851.4 1507.5 1450.3 1391.6 1417.1 1775.7 1493.3 1412.9 1573.4 1528.6 1982.6 1528.4 1502.7 1993.8 1462.5 1473.7 1990.1 1845.3 1926.6 1814.9 1817.4 1850.5 1444.4 1517.0 1394.2 1813.8 1806.9 2024.8 1692.7 (Ma) Best Best age 23.1 31.7 37.7 31.0 29.2 23.0 24.0 35.4 91.2 26.3 17.9 17.8 39.4 30.5 39.3 19.2 50.0 32.3 52.6 18.3 25.6 19.9 22.9 30.7 67.0 21.9 46.6 59.0 32.7 90.9 28.3 35.9 18.1 18.7 37.8 22.5 42.5 23.1 65.1 46.3 25.8 25.5 42.3 22.5 ± 117.4 (Ma) Pb* Pb* 412.5 567.8 1999.8 1847.6 1836.0 2123.9 1800.8 1494.9 1815.7 1813.8 1493.0 1828.8 1926.7 1988.5 1460.4 2021.1 1851.4 1507.5 1450.3 1391.6 1417.1 1775.7 1493.3 1412.9 1573.4 1528.6 1982.6 1528.4 1502.7 1993.8 1462.5 1473.7 1990.1 1845.3 1926.6 1814.9 1817.4 1850.5 1444.4 1517.0 1394.2 1813.8 1806.9 2024.8 1692.7 206 207 14.3 19.0 33.5 18.0 15.9 13.8 14.2 18.6 45.3 14.9 13.1 12.3 17.8 17.9 20.1 20.7 11.0 24.9 14.9 51.9 11.8 15.9 15.4 20.7 25.1 13.5 13.8 24.7 35.8 20.1 67.2 19.7 21.5 12.0 18.1 29.7 35.0 23.2 15.3 29.2 19.5 14.7 18.4 23.9 18.6 ± (Ma) U Pb* 486.5 504.9 1999.9 1806.8 1713.8 2092.7 1777.9 1445.1 1723.1 1768.7 1398.0 1824.7 1885.4 1954.6 1465.0 2002.2 1789.0 1460.5 1387.5 1358.9 1302.2 1741.9 1462.6 1338.5 1386.1 1474.7 1965.2 1494.7 1421.7 1969.1 1391.5 1466.5 1972.2 1818.4 1911.4 1800.0 1767.6 1853.2 1390.2 1455.8 1293.7 1822.4 1648.5 1947.1 1516.3 235 207 Apparent ages (Ma) ages Apparent 4.8 6.7 17.2 21.8 49.6 17.6 15.4 16.6 15.7 15.9 42.5 15.9 18.6 16.6 13.1 18.8 15.2 12.8 24.2 12.9 73.1 15.0 20.0 21.0 28.2 35.8 16.8 25.9 42.9 23.5 90.6 26.8 24.1 15.7 30.1 44.3 60.4 22.1 19.8 19.7 12.9 15.9 24.1 22.3 25.3 ± (Ma) U* Pb* 502.4 491.1 2000.0 1771.8 1615.5 2061.2 1758.4 1411.4 1648.0 1730.7 1336.6 1821.1 1848.2 1922.7 1468.2 1983.9 1735.9 1428.4 1347.0 1338.2 1233.5 1713.9 1441.5 1292.5 1267.7 1437.5 1948.8 1471.1 1368.1 1945.7 1345.6 1461.5 1955.2 1794.9 1897.5 1787.2 1725.7 1855.5 1355.1 1414.2 1233.9 1830.0 1527.1 1874.9 1393.2 238 206 0.61 0.63 0.86 0.49 0.53 0.73 0.63 0.47 0.59 0.57 0.76 0.71 0.43 0.54 0.42 0.19 0.70 0.60 0.54 0.92 0.71 0.75 0.87 0.90 0.86 0.42 0.63 0.62 0.74 0.61 0.84 0.81 0.58 0.71 0.87 0.81 0.95 0.50 0.80 0.41 0.43 0.58 0.78 0.50 0.86 corr. error 1.0 1.4 3.5 1.0 1.0 1.3 1.1 1.1 3.5 1.0 1.2 1.0 1.0 1.1 1.0 1.0 1.0 2.0 1.1 6.5 1.0 1.6 1.8 2.5 2.8 1.4 1.0 2.0 3.5 1.4 7.5 2.1 1.4 1.0 1.8 2.8 4.0 1.4 1.6 1.6 1.2 1.0 1.8 1.4 2.0 ± (%) U Pb* 0.3638 0.3163 0.2848 0.3768 0.3136 0.2448 0.2913 0.3080 0.2304 0.3264 0.3320 0.3475 0.2558 0.3604 0.3090 0.0810 0.2480 0.2324 0.2307 0.2109 0.3046 0.2506 0.2220 0.2173 0.2498 0.0792 0.3530 0.2563 0.2364 0.3523 0.2321 0.2545 0.3543 0.3211 0.3422 0.3195 0.3070 0.3335 0.2339 0.2453 0.2110 0.3283 0.2673 0.3376 0.2413 238 206 1.6 2.2 4.0 2.0 1.9 1.8 1.7 2.2 6.0 1.8 1.5 1.4 2.3 2.0 2.4 5.3 1.4 3.3 2.0 7.1 1.4 2.1 2.1 2.7 3.2 3.4 1.6 3.2 4.7 2.3 8.9 2.5 2.5 1.4 2.1 3.5 4.2 2.7 2.0 3.8 2.7 1.7 2.3 2.8 2.4 ± (%) Isotope ratios Isotope U* Pb* 6.1679 4.9267 4.4076 6.8542 4.7601 3.1504 4.4578 4.7081 2.9623 5.0319 5.4037 5.8549 3.2326 6.1840 4.8234 0.6147 3.2138 2.9215 2.8127 2.6055 4.5596 3.2225 2.7367 2.9161 3.2732 0.6442 5.9271 3.3583 3.0557 5.9537 2.9370 3.2388 5.9752 4.9943 5.5698 4.8872 4.7019 5.2035 2.9320 3.1943 2.5753 5.0185 4.0708 5.8047 3.4520 235 207 1.3 1.8 2.1 1.8 1.6 1.2 1.3 2.0 4.8 1.5 1.0 1.0 2.1 1.7 2.2 5.2 1.0 2.6 1.4 1.7 2.8 1.0 1.4 1.0 1.2 1.6 3.1 1.2 2.5 3.1 1.8 4.8 1.5 2.0 1.0 1.0 2.1 1.2 2.4 1.2 3.4 2.4 1.4 2.4 1.2 ± (%) Pb* Pb* 8.1317 8.8527 8.1763 8.9094 7.5795 9.0839 9.0099 9.0192 8.9448 8.4721 8.1837 8.0347 8.8337 9.0535 9.2098 8.2110 8.1595 8.8638 8.4723 9.0135 9.0011 8.8381 9.0189 8.0179 9.6363 206 207 10.7126 10.7234 10.9094 18.1797 10.6415 10.9675 11.3098 11.1599 10.7219 11.1849 10.2751 10.5232 16.9432 10.5246 10.6685 10.8974 10.8332 11.0015 10.5880 11.2946 1.3 1.9 1.4 1.3 1.2 1.2 1.9 1.6 1.8 1.4 1.4 1.6 2.0 1.8 2.1 1.5 1.4 0.9 2.0 2.7 1.1 2.0 1.9 1.7 0.6 1.8 3.0 2.0 3.6 1.4 1.8 0.5 2.3 1.0 1.0 1.7 1.7 1.1 1.2 1.2 1.8 1.6 1.6 2.3 3.0 U/Th 8774 2554 9236 9828 9474 7342 6916 4864 8326 8754 5220 Pb Pb 13760 12820 25996 17706 17128 13174 10064 15622 15762 19620 31216 29672 34040 25190 11334 27470 16044 18370 20194 16912 12306 34736 10164 32066 19694 25950 13576 38882 24780 23378 12284 13608 33798 34370 206 204 79 87 95 90 54 97 97 94 87 97 71 81 66 66 54 46 94 40 76 135 134 206 101 145 202 164 215 174 174 130 151 126 187 366 117 131 117 103 290 240 195 132 143 183 326 U (ppm) Analysis VMN18-13 VMN18-12 VMN18-34 VMN18-33 VMN18-11 VMN18-6 VMN18-42 VMN18-32 VMN18-31 VMN18-30 VMN18-27 VMN18-26 VMN18-25 VMN18-24 VMN18-20 VMN18-10 VMN18-5 VMN18-4 VMN18-41 VMN18-40 VMN18-39 VMN18-38 VMN18-29 VMN18-23 VMN18-22 VMN18-19 VMN18-18 VMN18-9 VMN18-3 VMN18-44 VMN18-37 VMN18-36 VMN18-28 VMN18-21 VMN18-17 VMN18-16 VMN18-15 VMN18-14 VMN18-8 VMN18-2 VMN18-1 VMN18-43 VMN18-7 VMN17-98 VMN17-95

Geologica Acta, 9(3-4), 265-272 (2011) VIII DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 18.3 19.1 18.0 22.7 28.2 39.3 36.0 71.2 50.0 42.6 46.9 38.9 31.3 30.6 43.2 34.6 29.5 27.1 33.1 37.2 21.9 29.8 56.2 50.1 45.4 30.5 27.3 37.5 25.2 17.8 34.0 23.2 17.8 34.4 31.5 29.4 18.3 38.2 20.8 20.0 26.4 37.7 27.4 29.3 46.0 ± (Ma) 1795.0 1426.7 2134.2 1408.3 1816.9 1823.6 1456.6 1175.6 1801.6 1835.9 1465.4 1779.0 1807.6 1373.8 1968.8 2015.0 1513.2 1986.0 1802.8 1481.2 1779.0 1388.9 1529.0 1844.5 1413.5 1922.4 1431.8 1514.1 1797.1 1998.1 1815.0 1795.1 1982.4 2036.9 1424.8 1518.5 1779.6 2006.3 1384.7 1468.6 1803.3 1825.4 1797.1 1434.4 1427.7 (Ma) Best Best age 18.3 19.1 18.0 22.7 28.2 39.3 36.0 71.2 50.0 42.6 46.9 38.9 31.3 30.6 43.2 34.6 29.5 27.1 33.1 37.2 21.9 29.8 56.2 50.1 45.4 30.5 27.3 37.5 25.2 17.8 34.0 23.2 17.8 34.4 31.5 29.4 18.3 38.2 20.8 20.0 26.4 37.7 27.4 29.3 46.0 ± (Ma) Pb* Pb* 1795.0 1426.7 2134.2 1408.3 1816.9 1823.6 1456.6 1175.6 1801.6 1835.9 1465.4 1779.0 1807.6 1373.8 1968.8 2015.0 1513.2 1986.0 1802.8 1481.2 1779.0 1388.9 1529.0 1844.5 1413.5 1922.4 1431.8 1514.1 1797.1 1998.1 1815.0 1795.1 1982.4 2036.9 1424.8 1518.5 1779.6 2006.3 1384.7 1468.6 1803.3 1825.4 1797.1 1434.4 1427.7 206 207 21.5 10.7 12.8 28.9 15.5 35.0 16.3 26.1 27.5 29.9 21.3 25.3 41.3 23.0 31.1 19.4 15.4 15.8 23.5 17.3 15.9 13.8 24.5 38.4 20.4 28.9 14.6 17.8 16.3 12.3 28.8 13.6 19.5 23.1 14.7 22.3 32.9 20.5 18.1 22.2 15.1 22.9 15.0 22.3 20.0 ± (Ma) U Pb* 1763.3 1380.5 2111.3 1383.0 1786.2 1824.2 1415.1 1176.3 1789.8 1740.8 1427.9 1728.6 1749.1 1333.4 1938.4 1976.0 1467.8 1965.5 1766.7 1497.9 1756.4 1361.1 1475.2 1579.4 1387.1 1883.2 1386.1 1494.7 1779.7 1986.2 1710.6 1781.9 1898.7 1962.1 1385.7 1329.9 1745.9 1929.2 1352.3 1411.2 1760.8 1725.9 1721.4 1404.3 1427.4 235 207 Apparent ages (Ma) ages Apparent 36.1 12.2 17.8 44.8 15.4 55.9 12.5 11.3 27.5 39.9 16.1 32.2 69.4 31.5 44.0 18.1 15.7 16.8 32.6 13.5 22.5 12.1 12.9 48.8 15.9 46.9 15.8 14.6 21.2 17.0 42.1 15.5 32.4 29.7 12.8 28.5 57.6 16.1 26.1 33.5 16.2 26.3 14.6 31.1 12.8 ± (Ma) U* Pb* 1736.6 1350.8 2087.8 1366.7 1760.0 1824.7 1387.7 1176.7 1779.7 1662.6 1402.9 1687.3 1700.6 1308.4 1910.1 1939.0 1436.6 1946.1 1736.3 1509.7 1737.5 1343.5 1438.1 1388.5 1369.9 1847.8 1356.6 1481.2 1764.9 1974.7 1626.6 1770.7 1823.1 1891.9 1360.4 1216.0 1717.8 1858.3 1331.9 1373.4 1725.1 1645.1 1659.9 1384.6 1427.1 238 206 0.92 0.71 0.70 0.95 0.54 0.85 0.47 0.28 0.54 0.76 0.46 0.71 0.94 0.86 0.74 0.48 0.62 0.55 0.76 0.45 0.78 0.54 0.32 0.82 0.48 0.86 0.67 0.48 0.70 0.71 0.84 0.62 0.90 0.68 0.53 0.86 0.97 0.42 0.89 0.93 0.59 0.66 0.55 0.85 0.38 corr. error 2.4 1.0 1.0 3.6 1.0 3.5 1.0 1.1 1.8 2.7 1.3 2.2 4.6 2.7 2.7 1.1 1.2 1.0 2.1 1.0 1.5 1.0 1.0 3.9 1.3 2.9 1.3 1.1 1.4 1.0 2.9 1.0 2.0 1.8 1.0 2.6 3.8 1.0 2.2 2.7 1.1 1.8 1.0 2.5 1.0 ± (%) U Pb* 0.3092 0.2331 0.3825 0.2362 0.3139 0.3272 0.2402 0.2003 0.3180 0.2942 0.2431 0.2992 0.3019 0.2250 0.3449 0.3509 0.2496 0.3524 0.3091 0.2639 0.3093 0.2317 0.2499 0.2403 0.2368 0.3319 0.2342 0.2583 0.3149 0.3584 0.2870 0.3161 0.3268 0.3411 0.2349 0.2076 0.3054 0.3341 0.2295 0.2374 0.3068 0.2907 0.2937 0.2396 0.2478 238 206 2.6 1.4 1.4 3.8 1.8 4.1 2.1 3.7 3.3 3.6 2.8 3.0 4.9 3.1 3.6 2.2 2.0 1.8 2.8 2.2 1.9 1.8 3.1 4.8 2.7 3.4 1.9 2.3 1.9 1.4 3.5 1.6 2.3 2.7 1.9 3.0 3.9 2.4 2.4 2.9 1.8 2.8 1.8 2.9 2.6 ± (%) Isotope ratios Isotope U* Pb* 4.6777 2.8945 6.9989 2.9043 4.8074 5.0291 3.0296 2.1851 4.8282 4.5533 3.0806 4.4872 4.5993 2.7182 5.7466 6.0014 3.2442 5.9291 4.6969 3.3721 4.6396 2.8209 3.2753 3.7371 2.9198 5.3895 2.9160 3.3584 4.7706 6.0716 4.3908 4.7831 5.4879 5.9059 2.9145 2.7054 4.5814 5.6858 2.7879 3.0140 4.6638 4.4729 4.4485 2.9869 3.0786 235 207 1.0 1.0 1.0 1.2 1.6 2.2 1.9 3.6 2.8 2.4 2.5 2.1 1.7 1.3 1.6 2.4 2.0 1.6 1.5 1.8 2.0 1.2 1.6 3.0 2.8 2.4 1.7 1.4 2.0 1.4 1.0 1.9 1.0 1.9 1.6 1.6 1.0 2.2 1.1 1.1 1.5 2.1 1.5 1.5 2.4 ± (%) Pb* Pb* 9.1900 9.1128 7.5347 9.0037 8.9704 9.0799 8.9097 9.1933 9.0499 9.1122 8.2747 8.0625 8.1952 9.0737 9.1931 8.8675 8.4921 9.1021 8.1394 9.0129 8.2117 7.9633 8.1022 9.0714 8.9614 9.1023 206 207 11.1044 11.2115 10.9314 12.6362 10.8810 11.4151 10.6096 10.7904 11.3255 10.5210 11.1809 11.0744 10.6048 11.1152 10.5800 11.3504 10.8624 11.0598 11.0982 1.8 1.6 2.1 1.5 2.6 2.0 1.5 2.0 2.0 0.8 1.6 1.3 2.1 1.5 2.0 1.3 2.1 1.3 1.3 1.3 1.1 1.3 0.8 1.5 1.7 1.1 1.2 2.5 2.8 2.0 2.5 1.0 0.8 1.0 1.7 2.3 2.8 1.7 2.8 1.5 4.0 1.5 1.6 2.5 1.1 U/Th 3862 8546 6130 Pb Pb 25090 16048 16638 31998 12158 11698 16854 17842 10320 24510 23186 18036 15588 27146 15428 16576 14134 11448 33450 10040 18620 10686 23928 11186 16980 17992 20790 25486 10382 12400 23224 23092 20450 21508 28832 15292 48104 31044 37606 17432 14530 14648 206 204 91 95 67 78 51 35 95 50 75 67 48 86 93 48 84 97 64 76 125 245 110 113 204 224 135 110 111 180 134 258 162 286 100 147 205 146 143 214 259 255 214 331 196 103 113 U (ppm) Analysis VMN18-80 VMN18-66 VMN18-65 VMN18-79 VMN18-73 VMN18-72 VMN18-64 VMN18-63 VMN18-59 VMN18-58 VMN18-57 VMN18-56 VMN18-55 VMN18-78 VMN18-77 VMN18-71 VMN18-62 VMN18-61 VMN18-54 VMN18-52 VMN18-87 VMN18-86 VMN18-76 VMN18-70 VMN18-69 VMN18-68 VMN18-60 VMN18-53 VMN18-51 VMN18-89 VMN18-88 VMN18-85 VMN18-84 VMN18-83 VMN18-82 VMN18-81 VMN18-75 VMN18-74 VMN18-67 VMN18-50 VMN18-49 VMN18-48 VMN18-47 VMN18-46 VMN18-45

Geologica Acta, 9(3-4), 265-272 (2011) IX DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 30.8 66.2 21.8 19.1 25.3 20.1 46.2 41.9 42.6 18.7 34.1 55.8 22.6 20.7 28.1 13.8 19.4 39.5 32.8 18.2 24.4 21.7 28.7 24.1 30.7 21.0 42.6 30.5 20.0 50.0 18.2 36.0 22.3 63.6 18.3 19.1 36.4 45.8 38.5 18.2 61.1 17.8 17.8 36.0 32.7 ± (Ma) 794.4 970.4 965.1 976.1 1520.9 1461.1 1388.7 1421.1 1046.8 1799.8 1349.0 2000.6 1256.0 1815.1 1262.7 1364.7 1735.4 1012.3 1990.5 1433.3 1566.0 2025.0 1796.9 1173.1 1465.6 1375.7 1482.8 1454.3 1216.5 1834.9 1445.6 1979.6 1797.5 1008.0 1515.4 1563.0 1773.1 1449.3 1914.9 2015.8 1455.6 1811.4 1987.7 1978.1 1884.7 (Ma) Best Best age 30.8 66.2 21.8 19.1 25.3 20.1 46.2 41.9 42.6 18.7 34.1 55.8 22.6 20.7 28.1 22.7 19.4 39.5 32.8 18.2 24.4 21.7 28.7 24.1 30.7 21.0 42.6 30.5 20.0 50.0 18.2 36.0 22.3 63.6 18.3 19.1 36.4 45.8 38.5 61.1 18.2 17.8 17.8 36.0 32.7 ± (Ma) Pb* Pb* 789.2 970.4 965.1 976.1 1520.9 1461.1 1388.7 1421.1 1046.8 1799.8 1349.0 2000.6 1256.0 1815.1 1262.7 1364.7 1735.4 1012.3 1990.5 1433.3 1566.0 2025.0 1796.9 1173.1 1465.6 1375.7 1482.8 1454.3 1216.5 1834.9 1445.6 1979.6 1797.5 1008.0 1515.4 1563.0 1773.1 1449.3 1914.9 2015.8 1455.6 1811.4 1987.7 1978.1 1884.7 206 207 9.1 32.7 28.7 11.4 14.1 15.5 17.8 20.0 30.9 17.1 63.7 14.5 23.1 16.8 16.2 11.7 18.0 40.7 21.1 11.9 11.1 13.1 13.5 12.5 14.6 10.4 22.3 14.4 13.1 16.7 15.6 12.9 12.2 27.2 20.6 11.4 19.4 24.3 19.4 19.9 13.4 27.4 12.2 29.9 12.0 ± (Ma) U Pb* 793.0 981.2 996.2 989.8 997.2 1480.3 1472.5 1366.8 1422.6 1036.4 1794.1 1368.7 1718.4 1233.5 1626.8 1248.7 1373.9 1746.5 1007.5 1958.6 1430.7 1394.8 2015.6 1788.1 1184.1 1471.8 1375.7 1444.2 1447.4 1216.6 1808.4 1417.6 1976.5 1796.9 1511.1 1436.2 1775.5 1438.0 1865.3 2037.0 1461.4 1777.9 1820.2 1928.6 1734.7 235 207 Apparent ages (Ma) ages Apparent 9.3 9.1 9.2 9.3 9.3 50.2 16.3 12.2 19.8 19.3 28.1 14.5 38.6 11.1 11.3 12.4 24.4 16.7 13.8 27.0 57.5 26.7 15.6 10.9 16.4 12.4 12.7 12.9 11.1 18.7 12.6 17.0 24.5 13.4 12.2 34.8 14.0 16.0 17.6 19.3 19.2 45.5 16.3 42.7 ± 103.2 (Ma) U* Pb* 794.4 986.0 990.9 1452.1 1480.4 1352.9 1423.6 1031.4 1789.1 1381.3 1496.5 1220.7 1485.3 1240.6 1379.8 1755.7 1005.3 1928.5 1429.0 1285.5 2006.4 1780.5 1190.2 1476.1 1375.7 1418.1 1442.6 1216.6 1785.5 1399.1 1973.5 1000.9 1796.4 1508.1 1006.8 1352.1 1777.6 1430.3 1821.1 2057.9 1465.3 1749.5 1677.5 1882.8 1613.0 238 206 0.92 0.33 0.66 0.84 0.85 0.85 0.44 0.77 0.42 0.99 0.50 0.33 0.79 0.70 0.53 0.86 0.90 0.92 0.64 0.71 0.63 0.73 0.56 0.62 0.53 0.68 0.45 0.53 0.67 0.32 0.38 0.84 0.49 0.65 0.53 0.28 0.91 0.74 0.45 0.36 0.59 0.78 0.95 0.71 0.83 corr. error 3.9 1.2 1.0 1.6 2.0 1.8 1.2 2.9 1.0 7.8 1.0 1.0 1.6 1.0 1.0 1.8 2.1 4.9 1.6 1.0 1.0 1.2 1.0 1.0 1.0 1.0 1.2 1.0 1.0 1.0 1.0 1.6 1.0 1.0 1.0 1.0 2.2 1.1 1.0 1.0 1.5 1.3 3.1 1.0 3.0 ± (%) U Pb* 0.2526 0.2582 0.2335 0.2471 0.1735 0.3199 0.2390 0.2613 0.2085 0.2591 0.2122 0.2387 0.3131 0.1688 0.3487 0.1311 0.2482 0.2207 0.3651 0.3181 0.2028 0.2573 0.2379 0.2461 0.2508 0.2077 0.3191 0.2424 0.3582 0.1680 0.1653 0.3214 0.1662 0.2636 0.1690 0.2334 0.3175 0.2484 0.3264 0.3761 0.2552 0.3118 0.2972 0.3392 0.2843 238 206 4.2 3.7 1.5 1.8 2.4 2.1 2.7 3.7 2.4 7.8 2.0 3.1 2.0 1.4 1.9 2.1 2.3 5.4 2.4 1.4 1.6 1.7 1.8 1.6 1.9 1.5 2.6 1.9 1.5 3.2 2.6 1.9 2.0 1.5 1.9 3.5 2.5 1.5 2.3 2.8 2.5 1.6 3.2 1.4 3.6 ± (%) Isotope ratios Isotope U* Pb* 3.2968 3.2639 2.8425 3.0596 1.7751 4.8525 2.8494 4.4323 2.3698 3.9639 2.4205 2.8693 4.5846 1.6974 5.8819 1.1837 3.0921 2.9497 6.2796 4.8181 2.2098 3.2612 2.8762 3.1467 3.1597 2.3140 4.9359 3.0397 6.0042 1.6506 1.6283 4.8689 1.6675 3.4293 1.6699 3.1140 4.7468 3.1213 5.2781 6.4344 3.2174 4.7603 5.0053 5.6817 4.5201 235 207 1.6 2.5 3.5 1.1 1.0 1.3 1.1 2.4 2.4 2.2 1.0 1.7 2.9 1.2 1.0 1.6 1.1 1.0 2.1 1.9 1.0 1.2 1.1 1.5 1.3 1.6 1.1 2.4 1.6 1.1 3.0 1.0 1.8 1.2 1.6 3.4 1.0 1.0 2.0 2.6 2.0 1.0 1.0 1.0 2.0 ± (%) Pb* Pb* 9.1005 9.0886 8.1283 9.0126 9.4151 8.1747 8.0171 9.1034 8.9149 8.2249 9.2231 8.5278 8.0588 9.0309 8.1872 8.2314 8.6722 206 207 10.5663 13.9951 10.9054 11.3270 11.1366 13.4775 11.5627 12.1301 12.0883 11.4692 13.7095 15.2761 11.0659 10.3160 12.6519 10.8795 11.4039 10.7815 10.9443 12.3770 10.9950 14.0318 13.7389 10.5971 13.9561 10.3326 10.9732 10.9373 3.2 1.6 1.5 0.6 2.0 2.0 1.9 3.3 1.5 2.3 1.2 3.8 1.5 1.9 1.6 2.3 2.7 1.6 2.7 2.3 1.5 1.4 1.4 2.6 1.2 1.1 1.1 1.8 2.6 1.3 2.0 1.1 1.7 0.9 2.5 3.1 1.0 2.3 1.7 2.6 1.9 2.0 0.8 2.0 2.3 U/Th 9216 3304 7200 7872 8270 4590 9278 5906 5428 Pb Pb 14562 10968 11222 19006 12146 10178 13870 16450 18768 25208 16410 10706 15290 14842 22840 10328 19852 23082 12828 20314 18284 13024 15970 17188 15756 13240 16026 22038 12898 17206 46448 19610 36166 15746 26542 23446 206 204 75 21 77 56 46 88 68 57 87 68 74 90 66 29 73 32 94 65 82 83 142 101 104 113 113 250 183 218 111 164 345 276 159 125 113 151 396 127 117 203 119 217 127 123 141 U (ppm) Analysis VMN32-18 VMN32-17 VMN32-34 VMN32-27 VMN32-26 VMN32-25 VMN32-16 VMN32-33 VMN32-32 VMN32-31 VMN32-30 VMN32-24 VMN32-15 VMN32-10a VMN32-10 VMN32-4 VMN32-3 VMN32-37 VMN32-29 VMN32-22 VMN32-21 VMN32-13 VMN32-9 VMN32-8 VMN32-2 VMN32-1 VMN18-97 VMN18-96 VMN32-36 VMN32-28 VMN32-20 VMN32-12 VMN32-7 VMN32-6 VMN32-5 VMN18-100 VMN18-99 VMN18-98 VMN18-94 VMN18-95 VMN18-93 VMN18-92 VMN18-91 VMN18-90 VMN32-11

Geologica Acta, 9(3-4), 265-272 (2011) X DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 4.1 5.4 9.0 30.7 36.0 36.5 40.0 25.5 19.5 18.3 32.2 18.2 23.1 23.6 36.3 25.1 19.1 28.5 20.0 19.2 23.2 32.0 33.1 43.6 19.3 22.6 29.7 38.7 21.8 27.1 34.8 40.9 28.1 30.9 18.7 59.6 14.3 18.1 25.6 26.7 18.8 28.5 33.8 18.2 24.1 ± (Ma) 427.0 987.2 568.4 965.1 909.1 1397.3 1058.4 1015.9 1774.2 1586.4 1812.0 1777.6 1818.9 1816.5 1525.4 1848.1 1539.4 1998.1 1458.2 2033.1 1527.2 1412.9 1852.2 1133.2 1843.0 1515.8 1970.3 1809.7 1792.3 1567.6 1497.9 1508.8 1507.8 1998.4 2015.9 1828.9 1949.3 1825.9 1509.6 2731.8 1574.9 1824.3 1513.4 1820.0 1405.5 (Ma) Best Best age 30.7 36.0 36.5 40.0 25.5 19.5 18.3 32.2 18.2 23.1 23.6 36.3 25.1 19.1 28.5 20.0 19.2 23.2 32.0 33.1 94.7 43.6 19.3 22.6 29.7 38.7 21.8 27.1 34.8 40.9 26.8 28.1 30.9 18.7 59.6 44.5 31.7 18.1 25.6 26.7 18.8 28.5 33.8 18.2 24.1 ± (Ma) Pb* Pb* 383.0 987.2 562.1 946.0 927.0 1397.3 1058.4 1015.9 1774.2 1586.4 1812.0 1777.6 1818.9 1816.5 1525.4 1848.1 1539.4 1998.1 1458.2 2033.1 1527.2 1412.9 1852.2 1133.2 1843.0 1515.8 1970.3 1809.7 1792.3 1567.6 1497.9 1508.8 1507.8 1998.4 2015.9 1828.9 1949.3 1825.9 1509.6 2731.8 1574.9 1824.3 1513.4 1820.0 1405.5 206 207 6.9 17.6 14.6 16.0 20.1 13.6 12.4 20.6 17.2 11.9 12.5 14.0 19.5 15.1 11.0 16.7 11.5 22.2 13.9 16.1 17.7 14.9 19.7 12.8 13.5 20.0 20.7 12.0 13.8 13.6 25.5 23.3 17.5 12.0 38.3 14.8 13.8 12.0 13.5 32.6 12.4 20.8 18.5 11.9 15.4 ± (Ma) U Pb* 420.2 996.4 567.1 959.3 914.3 1323.1 1022.6 1009.5 1761.3 1585.2 1811.5 1692.6 1817.9 1769.2 1522.0 1845.5 1522.8 2009.6 1463.7 2035.6 1522.1 1368.6 1855.3 1129.8 1852.2 1494.7 1978.7 1809.2 1742.8 1510.4 1504.3 1522.6 1509.4 1895.1 1982.2 1754.2 1883.8 1818.7 1521.9 2729.4 1579.1 1797.7 1523.2 1806.2 1412.4 235 207 Apparent ages (Ma) ages Apparent 4.1 5.4 9.0 20.5 13.0 16.2 15.3 14.0 15.8 32.9 15.8 15.2 13.5 16.0 20.7 17.3 13.1 17.5 13.5 33.6 16.1 17.9 16.2 13.2 17.1 15.8 26.3 21.6 13.5 13.6 12.0 32.5 34.6 16.8 14.9 47.4 14.3 15.8 14.2 67.6 16.4 29.5 20.7 15.7 20.0 ± (Ma) U* Pb* 427.0 568.4 965.1 909.1 1277.7 1005.9 1006.5 1750.5 1584.4 1811.1 1624.8 1817.0 1729.4 1519.4 1843.2 1511.0 2020.7 1467.5 2038.0 1518.5 1340.3 1858.2 1128.1 1860.3 1479.8 1986.8 1808.8 1701.8 1469.9 1508.8 1532.6 1000.6 1510.5 1802.2 1950.0 1692.1 1825.0 1812.4 1530.7 2726.2 1582.3 1774.9 1530.3 1794.3 1416.9 238 206 0.74 0.62 0.69 0.42 0.59 0.68 0.92 0.49 0.71 0.63 0.61 0.62 0.58 0.71 0.53 0.69 0.94 0.62 0.73 0.48 0.23 0.40 0.68 0.63 0.73 0.62 0.66 0.57 0.60 0.74 0.81 0.63 0.50 0.70 0.67 0.42 0.74 0.71 0.61 0.88 0.76 0.77 0.65 0.71 0.78 corr. error 1.8 1.4 1.7 1.0 1.0 1.0 2.3 1.0 1.0 1.0 1.0 1.5 1.0 1.0 1.0 1.0 2.8 1.0 1.7 1.0 1.0 1.0 1.0 1.0 1.8 1.6 1.0 1.0 1.3 2.4 2.2 1.0 1.0 1.0 3.0 1.0 1.7 1.0 1.0 3.0 1.2 1.9 1.5 1.0 1.6 ± (%) U Pb* 0.2192 0.1689 0.1690 0.3120 0.2786 0.3244 0.2866 0.3256 0.3077 0.2658 0.3310 0.2641 0.3681 0.2556 0.3718 0.2656 0.2311 0.3341 0.1912 0.3345 0.0685 0.2580 0.3610 0.3239 0.3021 0.2561 0.2637 0.2684 0.1679 0.2640 0.3226 0.0922 0.3532 0.3002 0.3272 0.1615 0.1515 0.3246 0.2680 0.5264 0.2782 0.3170 0.2679 0.3209 0.2458 238 206 2.4 2.3 2.5 2.4 1.7 1.5 2.5 2.0 1.4 1.6 1.6 2.5 1.7 1.4 1.9 1.5 3.0 1.6 2.4 2.1 4.3 2.5 1.5 1.6 2.4 2.6 1.5 1.7 2.1 3.2 2.7 1.6 2.0 1.4 4.5 2.4 2.3 1.4 1.7 3.4 1.5 2.5 2.4 1.4 2.0 ± (%) Isotope ratios Isotope U* Pb* 2.6805 1.7376 1.7025 4.6670 3.7646 4.9540 4.2959 4.9915 4.7113 3.4768 5.1569 3.4807 6.2364 3.2271 6.4241 3.4775 2.8491 5.2167 2.0426 5.1974 0.5126 3.3581 6.0199 4.9407 4.5645 3.4260 3.3997 3.4797 1.6680 3.4217 5.4647 0.7481 6.0441 4.6272 5.3935 1.5721 1.4608 4.9962 3.4764 3.7360 4.8738 3.4824 4.9231 3.0187 235 207 13.7035 2.2 1.6 1.8 1.8 2.2 1.4 1.1 1.0 1.8 1.0 1.2 1.3 1.9 1.4 1.0 1.6 1.1 1.0 1.3 1.6 1.8 4.2 2.3 1.1 1.2 1.6 2.1 1.2 1.4 1.7 2.2 1.6 1.2 1.7 1.0 3.3 1.5 1.0 1.4 1.6 1.0 1.6 1.8 1.0 1.3 ± (%) Pb* Pb* 9.2176 9.0280 9.2001 8.9939 9.0055 8.8498 8.1394 7.9805 8.8302 8.8749 8.2680 9.0394 9.1262 8.1384 8.0582 8.9442 8.3655 8.9593 5.2963 8.9669 8.9886 206 207 10.6296 14.1633 11.2762 13.4003 13.6854 10.2043 10.5410 10.4631 10.9222 10.5311 11.1846 12.9090 18.4203 10.5952 10.3069 10.6956 10.6342 13.8805 10.6402 16.9882 14.2950 10.2669 10.6086 11.2281 1.3 3.2 1.9 2.6 2.4 1.8 2.1 1.7 1.9 1.3 1.0 0.8 1.7 1.0 1.1 0.7 1.0 1.9 2.0 1.3 1.6 0.5 1.6 1.2 2.0 1.7 2.1 1.5 2.5 1.2 2.2 1.1 1.1 4.7 1.1 2.3 2.6 2.1 1.9 2.2 1.5 1.4 1.8 2.2 115.4 U/Th 5562 4864 9150 8060 6800 9778 5700 4746 5384 9914 8404 7032 5812 Pb Pb 11744 16324 29488 16418 14666 15986 17034 10004 11722 11734 30904 11260 57770 16876 14916 15298 10456 20332 17510 23458 17552 39246 26612 31100 26992 35986 22362 28750 19502 25996 39740 23756 206 204 32 63 77 55 89 74 56 84 56 59 51 95 84 73 53 25 50 93 78 73 53 40 24 101 216 243 121 211 156 221 111 102 116 115 479 127 160 559 152 172 305 150 146 129 136 U (ppm) Analysis VMN32-81 VMN32-80 VMN32-74 VMN32-73 VMN32-79 VMN32-72 VMN32-60 VMN32-59 VMN32-53 VMN32-78 VMN32-71 VMN32-58 VMN32-52 VMN32-51 VMN32-77 VMN32-70 VMN32-67 VMN32-66 VMN32-57 VMN32-49 VMN32-44 VMN32-43 VMN32-69 VMN32-65 VMN32-64 VMN32-56 VMN32-55 VMN32-47 VMN32-46 VMN32-42 VMN32-41 VMN32-14 VMN32-40 VMN32-39 VMN32-83 VMN32-82 VMN32-76 VMN32-75 VMN32-68 VMN32-63 VMN32-62 VMN32-61 VMN32-54 VMN32-45 VMN32-38

Geologica Acta, 9(3-4), 265-272 (2011) XI DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 5.8 5.7 7.7 4.7 4.7 5.5 25.5 26.9 23.0 28.3 25.8 23.9 22.3 23.6 43.1 46.7 24.1 50.3 38.6 21.9 18.2 25.7 18.2 29.5 31.9 22.2 19.5 50.7 28.5 18.0 15.3 30.7 25.4 25.7 31.4 41.5 22.1 40.7 23.3 18.1 36.7 20.5 18.0 27.9 44.3 ± (Ma) 605.9 541.2 578.5 464.8 866.7 942.7 986.5 489.7 532.8 985.6 994.6 1507.7 1431.2 1792.3 1839.8 1972.9 1020.4 1761.1 1517.2 1411.8 1412.1 1685.9 1172.6 1569.3 1411.0 1818.2 1395.9 1790.1 1838.8 1834.8 1198.6 1812.0 1327.7 1995.0 1000.0 1787.6 1553.2 1034.5 1493.9 1403.3 2073.4 1824.9 1384.0 1845.2 1900.4 (Ma) Best Best age 33.1 25.5 26.9 23.0 28.3 25.8 73.2 23.9 22.3 23.6 43.1 46.7 24.1 50.3 38.6 21.9 18.2 25.7 18.2 29.5 31.9 22.2 68.4 50.7 28.5 18.0 58.4 30.7 25.4 25.7 31.4 41.5 22.1 40.7 51.2 23.3 18.1 36.7 20.5 93.1 18.0 27.9 44.3 ± 140.4 173.4 (Ma) Pb* Pb* 601.4 603.5 575.7 334.3 923.9 986.5 473.2 450.0 985.6 994.6 1507.7 1431.2 1792.3 1839.8 1972.9 1020.4 1761.1 1517.2 1411.8 1412.1 1685.9 1172.6 1569.3 1411.0 1818.2 1395.9 1790.1 1838.8 1834.8 1198.6 1052.2 1812.0 1327.7 1995.0 1000.0 1787.6 1553.2 1034.5 1493.9 1403.3 2073.4 1824.9 1384.0 1845.2 1900.4 206 207 8.3 9.7 14.9 17.1 13.3 15.6 28.0 17.5 16.1 11.9 48.0 12.5 40.1 19.9 17.8 20.7 22.2 11.9 19.8 27.7 25.4 11.7 42.9 25.9 10.8 25.2 49.9 14.3 17.5 20.4 11.3 16.7 13.5 11.7 14.7 16.4 19.3 14.5 12.0 16.3 22.3 12.8 17.5 10.6 15.2 ± (Ma) U Pb* 604.9 553.3 577.9 443.5 920.6 937.1 963.6 486.8 517.4 965.8 989.3 1491.3 1426.2 1638.4 1788.0 1968.7 1033.1 1537.5 1481.4 1348.3 1370.1 1630.6 1185.7 1564.8 1402.1 1779.7 1397.2 1728.5 1798.7 1778.8 1177.6 1605.4 1308.9 1811.7 1792.1 1558.1 1003.3 1019.6 1436.6 1415.0 2011.1 1824.0 1390.5 1839.7 1900.5 235 207 Apparent ages (Ma) ages Apparent 5.8 5.7 7.7 4.7 8.8 4.7 9.4 5.5 9.4 8.9 9.2 17.8 22.1 14.1 15.3 23.7 13.4 73.7 13.0 57.7 12.1 24.8 16.7 25.8 13.3 32.6 38.6 14.8 74.4 38.6 11.3 19.5 71.8 14.9 26.4 15.3 22.1 13.9 22.4 17.5 16.8 15.9 12.5 37.8 18.3 ± (Ma) U* Pb* 605.9 541.2 578.5 464.8 866.7 942.7 947.7 489.7 532.8 957.1 986.9 1479.8 1422.9 1521.2 1743.9 1964.6 1039.2 1380.2 1456.5 1308.7 1343.4 1588.0 1192.9 1561.5 1396.2 1746.9 1398.0 1678.0 1764.4 1731.5 1166.2 1452.6 1297.4 1656.6 1795.9 1561.7 1011.1 1012.7 1398.1 1422.7 1950.9 1823.2 1394.7 1834.8 1900.5 238 206 0.55 0.71 0.78 0.64 0.54 0.17 0.69 0.38 0.76 0.98 0.62 0.91 0.38 0.80 0.52 0.67 0.68 0.91 0.14 0.92 0.71 0.95 0.82 0.69 0.58 0.89 0.65 0.87 0.52 0.55 0.71 0.59 0.54 0.44 0.84 0.54 0.40 0.60 0.71 0.46 0.90 0.74 0.25 0.59 0.42 corr. error 1.0 1.4 1.7 1.0 1.0 1.1 1.4 1.4 1.4 5.9 1.0 4.9 1.0 1.8 1.5 1.9 1.1 2.1 1.1 3.1 1.0 4.8 2.5 1.1 2.4 5.5 1.3 1.8 1.7 1.0 1.4 1.0 1.0 1.0 1.8 1.4 1.0 1.0 1.0 1.0 2.4 1.1 1.1 1.0 1.0 ± (%) U Pb* 0.0985 0.2580 0.2470 0.2661 0.3107 0.0876 0.3563 0.0939 0.1749 0.2388 0.2535 0.2251 0.2317 0.2793 0.2033 0.2741 0.2418 0.3113 0.0748 0.2422 0.2973 0.3148 0.3081 0.1983 0.1439 0.2527 0.2229 0.2930 0.1575 0.1584 0.3213 0.2741 0.1698 0.1701 0.2422 0.2469 0.0789 0.3534 0.3269 0.2415 0.3293 0.3429 0.0862 0.1601 0.1654 238 206 1.8 1.9 2.2 1.6 1.9 6.6 2.0 3.6 1.8 6.1 1.6 5.4 2.6 2.2 3.0 2.8 1.6 2.4 7.7 3.3 1.4 5.1 3.1 1.5 4.2 6.2 1.9 2.1 3.3 1.8 2.0 1.7 1.8 2.3 2.1 2.5 2.5 1.7 1.4 2.2 2.6 1.5 4.3 1.7 2.4 ± (%) Isotope ratios Isotope U* Pb* 0.8144 3.3436 3.0740 4.0207 4.8178 0.7245 5.9507 0.7668 1.7662 3.5459 3.3014 2.7731 2.8550 3.9821 2.2148 3.6697 2.9782 4.7701 0.5477 2.9591 4.4867 4.8796 4.7654 2.1891 1.4761 3.8601 2.6293 4.9549 1.5166 1.5831 4.8412 3.6391 1.6862 1.7297 3.1157 3.0290 0.6152 6.2472 5.0277 2.9331 5.1214 5.4992 0.6646 1.5887 1.6493 235 207 1.5 1.4 1.4 1.3 1.6 6.5 1.5 3.4 4.2 1.2 1.2 1.3 2.3 2.4 1.3 2.5 2.1 1.1 1.0 7.6 1.3 1.0 1.6 1.8 1.1 3.4 2.8 1.5 1.0 2.8 1.5 1.4 1.4 1.5 2.1 1.2 2.1 2.3 1.3 1.0 1.9 1.1 1.0 1.4 2.2 ± (%) Pb* Pb* 9.1266 8.8906 8.2557 9.2839 9.6719 8.9971 9.1372 8.8958 8.9152 9.0280 8.1537 9.1497 7.8002 8.9642 8.8645 8.5969 206 207 16.6829 10.6406 11.0779 16.6669 16.8824 17.8758 13.6552 10.5872 11.1910 13.5598 11.1894 12.6549 10.2979 11.1958 18.8217 11.2841 12.4898 13.4414 11.6910 14.3164 13.7933 10.3865 13.8848 10.7183 11.2410 17.6897 11.3544 13.8909 13.8297 2.2 2.2 2.3 3.3 2.5 0.8 1.5 1.3 1.1 1.1 3.3 1.0 2.3 1.9 2.2 1.9 2.0 2.5 0.9 2.0 1.3 1.2 3.8 2.7 1.4 1.5 2.0 2.9 1.6 3.4 1.4 1.7 2.4 1.6 1.3 3.8 1.2 1.1 2.4 1.6 2.1 1.6 1.0 3.7 0.9 U/Th 7890 9682 9476 1642 4672 5968 3936 8828 1502 9868 4014 7866 9416 7552 4908 Pb Pb 16540 13784 26040 13330 17234 20028 20626 43822 10674 11872 10870 11656 14302 30424 45606 26810 30504 20810 10702 11960 33926 18208 20132 31680 19378 10520 19734 24002 26616 12938 206 204 81 79 68 46 83 67 98 80 74 39 82 94 34 47 87 42 69 99 64 116 155 111 223 115 126 243 282 286 170 167 358 167 197 117 159 102 270 156 123 113 163 155 129 340 171 U (ppm) Analysis VMN32-98 VMN32-97 VMN32-96 VMN35-5 VMN35-4 VMN35-3 VMN32-95 VMN32-91 VMN35-27 VMN35-26 VMN35-25 VMN35-24 VMN35-20 VMN35-12 VMN35-2 VMN32-94 VMN32-90 VMN35-23 VMN35-22 VMN35-18 VMN35-17 VMN35-16 VMN35-15 VMN35-14 VMN35-11 VMN35-10 VMN35-9 VMN35-8 VMN35-7 VMN35-1 VMN32-93 VMN32-89 VMN32-88 VMN35-21 VMN35-13 VMN35-6 VMN32-100 VMN32-99 VMN32-92 VMN32-87 VMN35-29 VMN35-28 VMN32-86 VMN32-85 VMN32-84

Geologica Acta, 9(3-4), 265-272 (2011) XII DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 8.3 6.0 34.1 34.8 53.3 38.6 19.0 19.6 31.7 18.6 18.1 27.7 29.3 22.0 35.0 28.0 27.4 23.9 37.6 18.4 30.1 24.6 19.7 21.0 27.1 18.3 22.0 40.2 26.7 25.3 40.8 23.8 34.3 38.5 23.3 43.4 23.3 25.6 24.6 50.1 20.2 28.7 12.5 18.2 25.3 ± (Ma) 485.0 588.0 928.1 1396.8 1230.3 1166.6 1835.6 2009.5 1892.0 1888.3 1635.1 1871.1 1455.0 1481.8 1878.4 1544.8 1481.2 1556.5 1466.9 1224.4 1975.7 1787.8 1258.7 1215.2 1559.4 1489.1 1755.8 1073.0 1527.6 1011.9 1796.9 1369.1 1021.8 1015.1 1122.7 1824.1 1044.6 1605.3 1169.3 1495.4 1453.1 1804.2 1274.6 1821.6 1851.1 (Ma) Best Best age 34.1 34.8 53.3 38.6 19.0 19.6 31.7 18.6 18.1 27.7 29.3 22.0 35.0 28.0 27.4 23.9 37.6 18.4 30.1 24.6 19.7 21.0 27.1 18.3 22.0 40.2 26.7 25.3 40.8 23.8 34.3 38.5 23.3 76.2 43.4 23.3 53.3 25.6 24.6 50.1 20.2 28.7 30.7 18.2 25.3 ± (Ma) Pb* Pb* 529.1 567.5 953.2 1396.8 1230.3 1166.6 1835.6 2009.5 1892.0 1888.3 1635.1 1871.1 1455.0 1481.8 1878.4 1544.8 1481.2 1556.5 1466.9 1224.4 1975.7 1787.8 1258.7 1215.2 1559.4 1489.1 1755.8 1073.0 1527.6 1011.9 1796.9 1369.1 1021.8 1015.1 1122.7 1824.1 1044.6 1605.3 1169.3 1495.4 1453.1 1804.2 1274.6 1821.6 1851.1 206 207 9.8 15.9 17.1 20.7 20.3 23.0 13.6 20.1 11.5 12.1 16.2 14.4 15.8 19.9 17.2 14.1 12.5 15.5 13.3 19.4 11.6 11.0 11.9 24.4 14.7 20.5 10.5 14.4 19.8 12.7 17.7 14.8 18.1 15.2 17.4 12.9 16.8 11.8 12.9 26.7 12.6 15.8 12.8 16.9 25.5 ± (Ma) U Pb* 967.6 997.8 492.7 583.8 935.6 1409.5 1215.1 1177.4 1816.2 1759.5 1888.2 1889.6 1628.4 1872.4 1449.3 1478.1 1873.7 1503.6 1476.5 1562.8 1467.5 1245.9 1968.1 1770.6 1251.7 1220.2 1546.3 1452.4 1708.6 1071.5 1537.4 1769.2 1382.9 1000.1 1126.0 1775.6 1067.5 1601.5 1180.6 1498.5 1471.4 1804.0 1291.1 1822.4 1845.7 235 207 Apparent ages (Ma) ages Apparent 9.2 8.3 6.0 9.9 13.7 18.0 13.6 17.3 35.1 19.0 25.2 14.3 16.3 19.6 13.5 22.4 22.8 21.7 13.9 13.1 11.4 18.9 24.9 11.3 13.1 13.7 36.1 21.6 20.1 15.3 19.4 14.8 20.3 10.3 26.5 15.0 14.2 22.0 13.4 29.2 15.7 18.6 12.5 27.3 42.4 ± (Ma) U* Pb* 948.2 990.2 989.9 485.0 588.0 928.1 1417.9 1206.6 1183.3 1799.3 1556.7 1884.8 1890.7 1623.1 1873.6 1445.4 1475.5 1869.4 1474.6 1473.2 1567.5 1467.9 1258.3 1960.8 1756.1 1247.6 1222.9 1536.8 1427.4 1670.3 1070.7 1544.6 1745.9 1391.8 1127.6 1734.5 1078.7 1598.6 1186.7 1500.7 1484.0 1803.8 1301.0 1823.2 1840.8 238 206 0.52 0.68 0.42 0.46 0.92 0.73 0.66 0.71 0.71 0.72 0.55 0.75 0.68 0.74 0.56 0.62 0.46 0.73 0.70 0.62 0.76 0.67 0.89 0.83 0.67 0.56 0.62 0.58 0.59 0.81 0.79 0.46 0.80 0.46 0.57 0.62 0.84 0.40 0.61 0.64 0.67 0.73 0.69 0.86 0.88 corr. error 1.1 1.6 1.3 1.1 2.5 1.2 1.5 1.0 1.0 1.5 1.0 1.4 1.7 1.7 1.0 1.0 1.0 1.1 1.6 1.0 1.2 1.0 2.8 1.5 1.0 1.5 1.0 1.0 1.6 1.6 2.2 1.0 1.7 1.8 1.5 1.0 2.0 1.1 1.0 2.2 1.0 1.6 1.5 1.7 2.7 ± (%) U Pb* 0.2460 0.2058 0.2015 0.3220 0.2731 0.3396 0.3408 0.2863 0.3373 0.2513 0.2572 0.3364 0.2570 0.2567 0.2753 0.2557 0.2156 0.3555 0.3131 0.2135 0.2089 0.2692 0.2479 0.2958 0.1807 0.2707 0.1585 0.3110 0.2410 0.1660 0.1660 0.1912 0.3087 0.0781 0.1822 0.2814 0.2021 0.0955 0.2621 0.2589 0.3229 0.2236 0.1548 0.3269 0.3305 238 206 2.1 2.4 3.0 2.4 2.8 1.6 2.3 1.4 1.4 2.1 1.9 1.8 2.5 2.2 1.8 1.6 2.2 1.5 2.3 1.6 1.5 1.5 3.2 1.8 1.5 2.6 1.7 1.7 2.6 2.0 2.8 2.2 2.2 3.9 2.6 1.6 2.4 2.7 1.6 3.4 1.5 2.2 2.1 2.0 3.0 ± (%) Isotope ratios Isotope U* Pb* 3.0074 2.3092 2.1886 4.9816 4.6566 5.4212 5.4298 3.9714 5.3219 3.1675 3.2874 5.3302 3.3967 3.2806 3.6607 3.2429 2.4110 5.9467 4.7188 2.4306 2.3257 3.5856 3.1803 4.3801 1.8727 3.5455 1.5933 4.7112 2.9038 1.6777 1.6715 2.0310 4.7469 0.6246 1.8614 3.8417 2.1985 0.7771 3.3745 3.2591 4.9099 2.5663 1.5128 5.0184 5.1577 235 207 1.3 1.8 1.8 2.7 2.1 1.1 1.1 1.8 1.0 1.0 1.5 1.5 1.2 1.9 1.5 1.5 1.3 1.9 1.0 1.7 1.3 1.0 1.1 1.4 1.0 1.1 2.1 1.3 1.4 2.1 1.2 1.7 1.9 1.3 3.5 2.2 1.3 2.4 1.3 2.6 1.1 1.5 1.5 1.0 1.4 ± (%) Pb* Pb* 8.9111 8.0874 8.6373 8.6550 9.9407 8.7383 8.7025 8.2427 9.1492 9.3108 9.1032 8.9679 9.0671 8.9805 8.8354 206 207 10.1012 11.2792 16.9458 12.2902 12.6933 10.9408 10.7872 10.4330 10.7909 10.3684 10.8724 12.3271 12.1129 12.3848 10.3521 10.7457 13.3034 10.5291 13.7126 11.4426 13.6458 13.6907 12.9771 17.2466 13.4925 12.6762 10.7099 10.9515 12.0148 14.1137 0.9 1.2 1.2 2.2 2.2 2.4 1.3 2.1 2.1 1.5 2.0 0.9 1.2 2.1 0.9 1.3 5.3 0.9 2.0 1.6 1.4 1.0 2.3 1.6 3.3 1.3 1.4 2.8 1.6 4.7 1.6 1.9 3.2 2.2 4.1 1.2 1.8 3.1 2.8 1.6 1.4 1.8 2.5 1.2 1.7 U/Th 6240 3374 5964 7834 6694 6474 9592 6048 Pb Pb 12848 10312 19226 23462 13862 31526 25796 14290 18628 19758 11658 15096 20828 10810 25090 13292 18164 15636 19894 26998 25238 11494 12092 11800 18350 16600 12660 56202 12136 18484 24568 17480 22942 14108 10552 23970 24910 206 204 97 39 86 80 48 93 86 52 79 85 73 48 67 68 77 94 84 82 142 188 296 149 157 150 139 217 148 147 196 196 194 119 127 148 129 159 594 115 289 169 146 125 164 145 123 U (ppm) Analysis VMN35-74 VMN35-60 VMN35-59 VMN35-53 VMN35-39 VMN35-37 VMN35-36 VMN35-73 VMN35-72 VMN35-71 VMN35-67 VMN35-58 VMN35-52 VMN35-51 VMN35-35 VMN35-77 VMN35-70 VMN35-66 VMN35-65 VMN35-64 VMN35-63 VMN35-62 VMN35-57 VMN35-56 VMN35-55 VMN35-50 VMN35-49 VMN35-46 VMN35-45 VMN35-44 VMN35-43 VMN35-34 VMN35-33 VMN35-32 VMN35-75 VMN35-69 VMN35-68 VMN35-61 VMN35-54 VMN35-48 VMN35-47 VMN35-42 VMN35-41 VMN35-40 VMN35-30

Geologica Acta, 9(3-4), 265-272 (2011) XIII DOI: 10.1344/105.000001698 M.I. NOGUERA et al. Detrital zircon geochronology of Venezuela passive margin 55.5 31.2 25.3 39.4 40.3 47.3 17.7 24.2 29.6 38.6 67.1 20.2 29.6 87.5 30.4 22.4 24.7 23.3 43.9 18.8 ± (Ma) 992.0 970.3 1499.9 1031.6 1798.1 1939.9 1096.3 1031.2 2059.1 2243.0 1566.3 2215.7 1430.3 1380.3 1550.1 1777.2 1590.8 1216.2 1068.7 1550.9 (Ma) Best Best age 55.5 31.2 25.3 39.4 40.3 47.3 17.7 24.2 38.6 29.6 67.1 20.2 29.6 87.5 30.4 22.4 24.7 23.3 43.9 18.8 ± (Ma) Pb* Pb* 992.0 970.3 1499.9 1031.6 1798.1 1939.9 1096.3 1031.2 2059.1 2243.0 1566.3 2215.7 1430.3 1380.3 1550.1 1777.2 1590.8 1216.2 1068.7 1550.9 206 207 30.5 13.3 14.8 31.9 16.4 16.7 12.5 20.2 27.2 17.5 22.7 13.5 18.0 35.9 21.5 15.3 13.8 11.0 16.2 14.0 ± (Ma) U Pb* 991.1 994.4 1499.1 1005.2 1756.2 1923.2 1110.5 1055.2 2067.4 2227.4 1579.4 2051.3 1442.4 1313.7 1544.1 1728.1 1595.8 1215.9 1080.0 1542.8 235 207 Apparent ages (Ma) ages Apparent 9.8 34.1 12.9 16.6 49.0 14.1 17.7 32.7 42.4 18.4 13.3 16.4 22.7 19.8 29.7 20.3 15.6 11.1 10.9 19.8 ± (Ma) U* Pb* 993.1 990.7 1498.5 1721.1 1907.8 1117.8 1066.8 2075.7 2210.4 1589.1 1005.4 1891.7 1450.5 1273.3 1539.7 1687.8 1599.5 1215.7 1085.6 1536.9 238 206 0.66 0.67 0.62 0.80 0.56 0.39 0.71 0.78 0.89 0.73 0.40 0.65 0.75 0.35 0.80 0.74 0.64 0.65 0.45 0.82 corr. error 2.6 1.4 1.1 3.0 1.4 1.0 1.0 1.8 3.0 2.0 1.4 1.0 1.8 1.7 2.2 1.4 1.1 1.0 1.1 1.5 ± (%) U Pb* 0.2617 0.1666 0.3060 0.3444 0.1893 0.1800 0.3799 0.4090 0.2796 0.1661 0.1688 0.3411 0.2523 0.2184 0.2698 0.2993 0.2816 0.2075 0.1834 0.2692 238 206 3.9 2.1 1.8 3.7 2.4 2.5 1.4 2.2 3.4 2.8 3.6 1.5 2.3 4.9 2.7 1.8 1.7 1.6 2.4 1.8 ± (%) Isotope ratios Isotope U* Pb* 3.3770 1.6912 4.6383 5.6463 1.9852 1.8269 6.6605 7.9676 3.7371 1.6541 1.6628 6.5398 3.1392 2.6466 3.5754 4.4845 3.8143 2.3118 1.8969 3.5695 235 207 2.9 1.5 1.4 2.2 2.0 2.3 1.0 1.4 1.6 1.9 3.3 1.2 1.6 4.6 1.6 1.2 1.3 1.2 2.2 1.0 ± (%) Pb* Pb* 9.0972 8.4099 7.8639 7.0779 7.1906 9.2022 206 207 10.6844 13.5798 13.1500 13.5824 10.3142 13.8472 13.9961 11.0833 11.3766 10.4036 10.1803 12.3783 13.3320 10.3994 1.7 4.7 2.3 4.5 1.7 1.8 1.1 3.3 3.7 1.9 2.1 0.6 1.1 1.5 6.1 2.8 2.3 1.5 1.7 0.8 U/Th 6718 6058 5028 2972 7704 1556 2886 Pb Pb 17330 31920 39042 19220 32152 45892 10362 77414 35642 25886 11484 11418 20142 206 204 45 55 61 56 31 13 146 199 169 112 133 509 106 531 182 190 103 148 110 180 U (ppm) Analysis VMN35-100 VMN35-99 VMN35-97 VMN35-96 VMN35-93 VMN35-86 VMN35-85 VMN35-84 VMN35-83 VMN35-82 VMN35-95 VMN35-92 VMN35-81 VMN35-91 VMN35-90 VMN35-89 VMN35-88 VMN35-87 VMN35-80 VMN35-78

Geologica Acta, 9(3-4), 265-272 (2011) XIV DOI: 10.1344/105.000001698