New paleontological and geological data on the Ordovician and Silurian of Bolivia

Gagnier, Pierre-Yves; Blieck, Alain; Emig, Christian C.; Sempéré, Thierry; Vachard, Daniel; Vanguestaine, Michel

doi:10.1016/s0895-9811(96)00018-1

Cited by 27 publications

(9 citation statements)

References 12 publications

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“…These findings are in good agreement with earlier descriptions by Steinmann & Hoek (1912), who figured a specimen of C. furcifera from Palca del Tunari near Cochabamba which probably has a middle to late Caradoc age (Gagnier, 1993;Gagnier et al 1996). Only the taxon C. rouaulti seems to be restricted to Lower Ordovician successions in Bolivia.…”

Section: E Implications For C Rugosa Biostratigraphysupporting

confidence: 92%

“…Branisa (1965) referred to the Liriuni succession as belonging to the uppermost Caradoc. Recent acritarch and brachiopod data in the surroundings of Cochabamba (Gagnier et al 1996) support a Llanvirn to Caradoc age for the Anzaldo Formation. As the Liriuni locality represents the uppermost part of the Anzaldo Formation only shortly below the contact with the lower Ashgill San Benito Formation (Suarez Soruco & Benedetto, 1996), it is likely that the Cruziana faunas indeed have a late Caradoc age.…”

Section: D Liriuni Near Cochabamba (17mentioning

confidence: 91%

“…However, Bolivia is the only place worldwide where Seilacher (1992) reports that the occurrence of the 'Cruziana rugosa Group' continues stratigraphically into the Upper Ordovician. Although Seilacher reassigned these Caradocian quartzites in Bolivia to the Middle Ordovician in a personal communication in Mángano & Buatois, 2003, the thick quartzitic units near Cochabamba are at least partly Caradoc in age (Gagnier et al 1996). If this were true, Bolivia would offer the unique possibility to find out about the real stratigraphic range of the 'Cruziana rugosa Group'.…”

Section: Introductionmentioning

confidence: 99%

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Biostratigraphic precision of the Cruziana rugosa group: a study from the Ordovician succession of southern and central Bolivia

Egenhoff

Weber

Lehnert³

et al. 2007

Geol. Mag.

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-Cruziana ichnospecies have been repeatedly reported to have biostratigraphic significance. This study presents a re-evaluation of the arthropod ichnotaxa of the Cruziana rugosa Group from bio-and/or lithostratigraphically well-defined Lower to Upper Ordovician siliciclastic sections of southern and central Bolivia. With the exception of Cruziana rouaulti, the ichnofaunas contain all the members of the Cruziana rugosa Group throughout the Ordovician (Arenig to Caradoc) successions in Bolivia. The Bolivian material therefore indicates that these arthropod ichnofossil assemblages are suitable for recognizing Ordovician strata in Bolivia. These findings cast doubt on their use as reliable indicators for a global intra-Ordovician (Arenig to Caradoc) biozonation of Peri-Gondwanan sedimentary successions.

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Section: E Implications For C Rugosa Biostratigraphysupporting

confidence: 92%

Section: D Liriuni Near Cochabamba (17mentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Biostratigraphic precision of the Cruziana rugosa group: a study from the Ordovician succession of southern and central Bolivia

Egenhoff

Weber

Lehnert³

et al. 2007

Geol. Mag.

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“…We compiled regional stratigraphic sections across southern Bolivia (∼18–23°S) to independently estimate the magnitude of exhumation by restoring the thermochronometer samples to original stratigraphic depth (Figure 3) (see details in Appendix A). Specifically, we constructed representative, regional sections measured from the range of thicknesses used in the balanced and restored section of McQuarrie [2002] because (1) it is the most proximal estimate that spans the entire study area, (2) its regional scale is most appropriate, and (3) the thickness variations themselves are derived from local field observations and supported by some of the compiled sections themselves [ Dunn et al , 1995; Sempere , 1995; Gagnier et al , 1996; Kley , 1996; Kley et al , 1997; Sempere et al , 1997; Horton et al , 2001; McQuarrie and DeCelles , 2001]. Our calculated average thicknesses are almost always within the compiled bounds (Figure 3).…”

Section: Methodsmentioning

confidence: 99%

Thermochronometer record of central Andean Plateau growth, Bolivia (19.5°S)

et al. 2008

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Quantifying the timing, magnitude, and rates of exhumation and deformation across the central Andes is a prerequisite for understanding the history of plateau rise. We present 23 new apatite and zircon fission track thermochronometer samples to chronicle the exhumation and deformation across the entire (∼500 km) Andean fold‐thrust belt at ∼19.5°S in Bolivia. Exhumation and deformation are constrained with inverse thermal modeling of the thermochronometer data, regional stratigraphy, geothermal gradients, and mass deficits inferred from a balanced section. Results suggest the following: (1) Initial exhumation of the Eastern Cordillera (EC) fore‐thrust and back‐thrust belts began in the late Eocene to early Oligocene (27–36 Ma) and continued in a distributed manner in the late Oligocene to early Miocene (19–25 Ma). Interandean zone (IA) exhumation began 19–22 Ma, followed by a third pulse of exhumation (11–16 Ma) in the EC back‐thrust belt and initial cooling in the westernmost Subandes (SA) 8–20 Ma. Finally, exhumation propagated eastward across the SA during the late Mio‐Pliocene (2–8 Ma). (2) Exhumation magnitudes are spatially variable and range from maximums of <8 km in the EC fore‐thrust belt to average values of ∼4–7 km across the EC, ∼2.5–3 km in the Altiplano, ∼4–6 km in the IA, and ∼3 km in the SA. (3) Exhumation rates range from ∼0.1 to 0.2 mm/a in the EC, from ∼0.1 to 0.6 mm/a in the IA, and from ∼0.1 to 0.4 mm/a to locally 1.4 mm/a or more in the eastern SA. We synthesize similar constraints with sediments throughout Bolivia and characterize plateau development by (1) distributed deformation throughout the Altiplano and EC regions from ∼20 to 40 Ma with minor deformation continuing until ∼10 Ma, (2) contemporaneous cessation of most EC deformation and exhumation of the IA ∼20 Ma implying establishment of the modern plateau width with significant, but unknown crustal thickness and elevation shortly thereafter by ∼15–20 Ma, and (3) dominantly eastward propagation of deformation from the IA since ∼20 Ma with minor out‐of‐sequence deformation in the central to eastern SA.

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“…Data on low-grade metamorphic rocks in northern Chile and sedimentary rocks from northern Argentina (Gagnier et al 1996;Egenhoff and Lucassen 2003) represent potential sources of province IIIb-type lead. The lead isotope characteristics of these rocks resemble very closely the upper crustal curve of Zartman and Doe (1981) (see Fig.…”

Section: Province Iiia -Paleozoic Sedimentary Rock Upper Crustal Sourcementioning

confidence: 99%

Andean Ores, Bronze Artifacts, and Lead Isotopes: Constraints on Metal Sources in Their Geological Context

MacFarlane

Lechtman

2014

J Archaeol Method Theory

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With a focus on bronze production in the south-central Andes during the Middle Horizon, this study reports the first archaeological use of lead isotope analysis to investigate metallic ores and metal artifacts in the Andean zone of South America. Because the vast majority of metal deposits in the Andean cordillera formed in a convergent plate boundary setting, lead isotope compositions of most Andean ore sources are not unique. Lead isotope ratios of central and south-central Andean ores define four geographically distinct ore lead isotope provinces, oriented and elongated parallel or sub-parallel to the trend of the Andean cordilleras. Consequently, ore lead isotope ratios vary strongly from west to east along transects through the coast, highlands and altiplano, but they exhibit much less variation from north to south. The strong west-to-east variation in ore lead isotope signatures allows discrimination between ore bodies, and ultimately between metal artifacts, as a function of macro-ecozone location: coast, junga-qiswa, puna, altiplano. We present the most up-to-date database of ore lead isotope signatures for the south-central Andes including those determined for ores we sampled over an approximate 250,000 km sq region within Bolivia, N. Chile, and NW Argentina. Lead isotope signatures of Cu-As-Ni bronze artifacts from Tiwanaku (altiplano capital) and San Pedro de Atacama (desert oasis entrepôt) establish that altiplano and high sierra ore bodies provided the metal for both assemblages. Conchopata (Wari) arsenic bronze artifacts exhibit lead isotope ratios compatible with the Julcani (Huancavelica) copper sulfarsenide deposit.

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New paleontological and geological data on the Ordovician and Silurian of Bolivia

Cited by 27 publications

References 12 publications

Biostratigraphic precision of the Cruziana rugosa group: a study from the Ordovician succession of southern and central Bolivia

Biostratigraphic precision of the Cruziana rugosa group: a study from the Ordovician succession of southern and central Bolivia

Thermochronometer record of central Andean Plateau growth, Bolivia (19.5°S)

Andean Ores, Bronze Artifacts, and Lead Isotopes: Constraints on Metal Sources in Their Geological Context

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