Isotopic Evidence for the Late Brasiliano (500-550 Ma) Ore-Forming Mineralization of the Araés Gold Deposit, Brazil

Geraldes, Mauro César; Tassinari, Colombo Celso Gaeta; Babinski, Marly; Martinelli, C.S.M.; Iyer, Brijesh; Barboza, E. S.; Pinho, Francisco Egídio Cavalcante; Onoe, Artur Takashi

doi:10.2747/0020-6814.50.2.177

Cited by 30 publications

(12 citation statements)

References 25 publications

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“…They found that the lower part of the succession was dominated by Nd isotopic ratios and T DM model ages that suggest a continental source from the Amazonian craton, while the upper siliciclastic succession shows lower Nd isotopic ratios that are consistent with a source from the Paraguay Belt itself, or another Neoproterozoic continental source. More recently, detrital zircon ages from the Diamantino Formation of 541 ± 7 Ma (Bandeira et al, 2012) and 40 Ar/ Ar cooling ages of biotite fl akes (Geraldes et al, 2008). The incipient stage of deformation in the form of early thrusting was inferred to be associated with clay mineral transformations and chemical remagnetization of carbonates in the Araras Group at ca.…”

Section: Tectonic Model and The Paraguay Belt Within South America Anmentioning

confidence: 99%

Age and provenance of the Cryogenian to Cambrian passive margin to foreland basin sequence of the northern Paraguay Belt, Brazil

McGee

Collins

Trindade

et al. 2014

Geological Society of America Bulletin

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The Paraguay Belt in central South America developed in response to the collision of the Amazonian craton, the São Francisco craton, and the Paranapanema block. The alleged "Brasiliano" age (ca. 620 Ma) of orogenesis has recently been questioned by paleo magnetic and radioisotopic ages that indicate the closing stages of orogenesis occurred well into the Cambrian. We investigated the timing of deposition and source areas for these sedimentary rocks overlying the Amazonian craton using integrated U-Pb and Hf isotope data of detrital zircons from within this sequence. In total, 742 detrital zircon U-Pb ages were analyzed from samples taken from the base to the top of this sedimentary succession. Maximum depositional ages from the uppermost part of this sequence of rocks, the Diamantino Formation, indicate that fi nal deposition began no earlier than 560 ± 13 Ma and possibly as young as the Cambrian. Given that zircon inheritance in these rocks continues up until this age and that known Amazonian craton ages are older than ca. 950 Ma, we considered other potential sources for these sediments. This was achieved by integrating the U-Pb detrital zircon data with Hf isotopic data from these zircons that have ε Hf values ranging from -18 to 12. The ε Hf signature is consistent, with a predominantly Amazonian source until the early Neoproterozoic, at which point the signal becomes signifi cantly more evolved. These data, when combined with other evidence discussed here, are consistent with an ocean to the east of the present-day Amazonian craton that did not close until the latest Ediacaran-Cambrian.

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Section: Tectonic Model and The Paraguay Belt Within South America Anmentioning

confidence: 99%

Age and provenance of the Cryogenian to Cambrian passive margin to foreland basin sequence of the northern Paraguay Belt, Brazil

McGee

Collins

Trindade

et al. 2014

Geological Society of America Bulletin

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“…The presence of late Cambrian strike-slip duplexes in the easternmost Paraguai belt (Martinelli, 1998;Geraldes et al, 2008) suggests a switch from frontal collision to a transfer zone along the east-west limb. We note that cleavage patterns within the Cuiabá Group display a similar curvature, suggesting that the interior of the belt was similarly rotated.…”

Section: Discussionmentioning

confidence: 99%

Closing the Clymene ocean and bending a Brasiliano belt: Evidence for the Cambrian formation of Gondwana, southeast Amazon craton

Tohver

Trindade

Solum

et al. 2010

Geology

116

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“…Regarding its age, there is some consensus on the Cryogenian Period based on the constraints of the successions deposited above. This group is metamorphosed to greenschist facies and the biotites from the uppermost units yield Ar-Ar plateau ages from 541 ± 0.7 to 531 ± 0.6 Ma (Geraldes et al 2008), interpreted as cooling ages after the assembly of Gondwana. The minimum depositional age is also given by the intrusion of the post-tectonic São Vicente granite, which has a U-Pb age obtained for zircons of 514 ± 10 Ma .…”

Section: Amazon Craton-northern Paraguai Beltmentioning

confidence: 97%

The Cryogenian and Ediacaran Records From the Amazon Palaeocontinent

Figueiredo

Babinski

2014

Springer Geology

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The Amazon Craton was involved in the buildup of the Rodinia and Gondwana supercontinents during the Neoproterozoic. During this era, Earth's surface was marked by important transformations including global glaciations, atmospheric and ocean oxygenation pulses, and the turnover of life forms. Most of these events were recorded on the margins of the Amazon Palaeocontinent in the time interval between the breakup of Rodinia and the assembly of Gondwana, today located on its southeastern border as part of the Paraguai Fold-Thrust Belt. This paper reports the age constraints obtained for the respective sedimentary successions based on several tools, including geochronology using U-Pb, Pb-Pb, and Ar-Ar methods, isotope chemostratigraphy of C and Sr, and palaeobiology. According to the results, the sedimentary successions record surface conditions from the early Cryogenian to the early Cambrian.

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Isotopic Evidence for the Late Brasiliano (500-550 Ma) Ore-Forming Mineralization of the Araés Gold Deposit, Brazil

Cited by 30 publications

References 25 publications

Age and provenance of the Cryogenian to Cambrian passive margin to foreland basin sequence of the northern Paraguay Belt, Brazil

Age and provenance of the Cryogenian to Cambrian passive margin to foreland basin sequence of the northern Paraguay Belt, Brazil

Closing the Clymene ocean and bending a Brasiliano belt: Evidence for the Cambrian formation of Gondwana, southeast Amazon craton

The Cryogenian and Ediacaran Records From the Amazon Palaeocontinent

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