Southernmost Exposures of the Arroyo del Soldado Group (Vendian to Cambrian, Uruguay): Palaeogeographic Implications for the Amalgamation of W-Gondwana

Gaucher, Claudio; Chiglino, Leticia; Peçoits, Ernesto

doi:10.1016/s1342-937x(05)71057-1

Cited by 48 publications

(19 citation statements)

References 20 publications

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“…The foreland belt consists of several volcano-sedimentary and sedimentary successions: the Arroyo del Soldado and the Maldonado Groups (Gaucher 2000;Gaucher et al 2003Gaucher et al , 2004Pecoits et al 2004Pecoits et al , 2008. The age is constrained by the occurrence of Ediacaran microfossils (Gaucher et al 2003) and U-Pb zircon dating of associated volcaniclastic rocks Oyhantçabal et al 2009).…”

Section: Neoproterozoic Volcano-sedimentary and Sedimentary Successionsmentioning

confidence: 99%

The Río de la Plata Craton: a review of units, boundaries, ages and isotopic signature

Oyhantçabal

Siegesmund

Wemmer

2010

Int J Earth Sci (Geol Rundsch)

193

168

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Section: Neoproterozoic Volcano-sedimentary and Sedimentary Successionsmentioning

confidence: 99%

The Río de la Plata Craton: a review of units, boundaries, ages and isotopic signature

Oyhantçabal

Siegesmund

Wemmer

2010

Int J Earth Sci (Geol Rundsch)

193

168

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“…The metamorphosed volcanosedimentary Lavalleja group is often correlated with the Porongos group in southern Brazil and thus, regarded as part of the same schist belt (Jost and Bitencourt 1980;Basei et al 2000Basei et al , 2008aSánchez Bettucci et al 2001). These older units of the Nico Pérz terrane are unconformably covered by Vendian-early Palaeozoic sedimentary successions of the Arroyo del Soldado group (Gaucher et al 2004b). The SSW-NNE-striking sinistral transcurrent Sierra Ballena Shear Zone (SBSZ) marks the border between the Nico Pérez terrane and the Cuchilla Dionisio terrane in the east (Fig.…”

Section: Geologic Setting: Tectonic Units Of S-brazil and Uruguaymentioning

confidence: 99%

“…Recent advances, in particular in the study of the Uruguay shield (e.g. Hartmann et al 2001Hartmann et al , 2002aBossi and Gaucher 2004;Gaucher et al 2004bGaucher et al , 2008Oyhantçabal et al 2007Oyhantçabal et al , 2009aPecoits et al 2008;Blanco et al 2009), offer important new data and interpretations. Controversial opinions about the number, tectonic setting and age of terranes, timing of accretional or collisional events, and number and polarity of subduction zones have led to proposition of partly conflicting plate tectonic scenarios (e.g.…”

Section: Introductionmentioning

confidence: 99%

Multiple accretion at the eastern margin of the Rio de la Plata craton: the prolonged Brasiliano orogeny in southernmost Brazil

Saalmann

Gerdes

Lahaye

et al. 2010

Int J Earth Sci (Geol Rundsch)

120

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The Neoproterozoic-Eoplalaeozoic Brasiliano orogeny at the eastern margin of the Rio de la Plata craton in southernmost Brazil and Uruguay comprises a complex tectonic history over 300 million years. The southern Brazilian Shield consists of a number of tectono-stratigraphic units and terranes. The São Gabriel block in the west is characterized by c.760-690 Ma supracrustal rocks and calc-alkaline orthogneisses including relics of older, c. 880 Ma old igneous rocks. Both igneous and metasedimentary rocks have positive eNd(t) values and Neoproterozoic TDM model ages; they formed in magmatic arc settings with only minor input of older crustal sources. A trondhjemite from the São Gabriel block intruding dioritc and tonalitic gneisses during the late stages of deformation (D 3 ) yield an U-Pb zircon age (LA-ICP-MS) of 701 ± 10 Ma giving the approximate minimum age of the São Gabriel accretionary event. The Encantadas block further east, containing the supracrustal Porongos belt and the Pelotas batholith, is in contrast characterized by reworking of Neoarchean to Palaeoproterozoic crust. The 789 ± 7 Ma zircon age of a metarhyolite intercalated with the metasedimentary succession of the Porongos belt provides a time marker for the basin formation. Zircons of a sample from tonalitic gneisses, constituting the Palaeoproterozoic basement of the Porongos belt, form a cluster at 2,234 ± 28 Ma, interpreted as the tonalite crystallization age. Zircon rims show ages of 2,100-2,000 Ma interpreted as related to a Palaeoproterozoic metamorphic event. The Porongos basin formed on thinned continental crust in an extensional or transtensional regime between c. 800-700 Ma. The absence of input from Neoproterozoic juvenile sources into the Porongos basin strongly indicates that the Encantadas and São Gabriel blocks were separated terranes that became juxtaposed next to each other during the Brasiliano accretional events. The tectonic evolution comprises two episodes of magmatic arc accretion to the eastern margin of the Rio de la Plata craton, (i) accretion of an intra-oceanic arc at c. 880 Ma (Passinho event) and (ii) accretion of the 760-700 Ma Cambaí/Vila Nova magmatic arc (São Gabriel event). The latter event also includes the collision of the Encantadas block with the Rio de la Plata craton to the west. Collision and crustal thickening was followed by sinistral shear along SW-NE-trending orogenparallel crustal-scale shear zones that can be traced from southern Brazil to Uruguay and have been active between 660 and 590 Ma. Voluminous granitic magmatism in the Pelotas batholith spatially related to shear zones is interpreted as late-to post-orogenic magmatism, possibly assisted by lithospheric delamination. It marks the transition to the post-orogenic molasse stage. Localized deformation by reactivation of preexisting shear zones continued Electronic supplementary material The online version of this article (

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“…The Minas Formation only contains metasedimentary rocks, with metapelite, quartzite, meta-arkose and stromatolite-bearing limestones. Some rocks attributed to the Lavalleja Group by Sanchez-Bettucci (1998) are now considered on the basis of fossil content to be younger, and have been correlated with the Vendian El Soldado Group (Gaucher 2000;Gaucher et al 1996Gaucher et al , 2004.…”

Section: The Lavalleja Metamorphic Complexmentioning

confidence: 99%

West Gondwana amalgamation based on detrital zircon ages from Neoproterozoic Ribeira and Dom Feliciano belts of South America and comparison with coeval sequences from SW Africa

et al. 2008

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Neoproterozoic-Cambrian amalgamation of West Gondwana involved the collision of several terranes of older crust that are now in eastern South America and western Africa. U -Pb (SHRIMP) detrital zircon ages from representative metasedimentary units of the Ribeira and Dom Feliciano belts (South America) and Gariep and Damara belts (Africa) provide constraints on the possible sediment source areas across probable suture zones. Ribeira detrital zircons are Palaeoproterozoic and Archaean. For the Dom Feliciano Belt, a contribution of Meso-and Neoproterozoic zircons is present, which definitely indicate Neoproterozoic sedimentation. It is proposed that the inflow of material to the Ribeira basin was essentially derived from the Paranapanema and Rio de la Plata cratons, whereas for the Damara and Gariep-Rocha belts source areas were from the Namaqua Belt. The Dom Feliciano Belt received sediments from the South American side and to a lesser degree from African sources. These results highlight the differences in the detrital zircon signatures across a proposed West Gondwanan suture, with those in the west being derived from distinctive South American basement sources and those in the east from distinctive African sources.

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Southernmost Exposures of the Arroyo del Soldado Group (Vendian to Cambrian, Uruguay): Palaeogeographic Implications for the Amalgamation of W-Gondwana

Cited by 48 publications

References 20 publications

The Río de la Plata Craton: a review of units, boundaries, ages and isotopic signature

The Río de la Plata Craton: a review of units, boundaries, ages and isotopic signature

Multiple accretion at the eastern margin of the Rio de la Plata craton: the prolonged Brasiliano orogeny in southernmost Brazil

West Gondwana amalgamation based on detrital zircon ages from Neoproterozoic Ribeira and Dom Feliciano belts of South America and comparison with coeval sequences from SW Africa

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