West Gondwana orogenies and Pangaea break-up: thermotectonic effects on the southernmost Mantiqueira Province, Brazil

Joao Pacifico Silveira Luiz Machado; Andrea Ritter Jelinek; Marcos Muller Bicca; Randell Stephenson; Frederico Antonio Genezini

doi:10.1144/jgs2019-018

West Gondwana orogenies and Pangaea break-up: thermotectonic effects on the southernmost Mantiqueira Province, Brazil

Joao Pacifico Silveira Luiz Machado, Andrea Ritter Jelinek, Marcos Muller Bicca, Randell Stephenson, Frederico Antonio Genezini

Universidade Federal do Rio Grande do Sul
Ctr Reator Pesquisas, Comissao Nacional de Energia Nuclear (CNEN), Instituto de Pesquisas Energeticas e Nucleares (IPEN), Inst Pesquisas Energet & Nucl

Research output: Contribution to journal › Article › peer-review

10 Citations (Scopus)

Abstract

Through the joint use of apatite fission tracks (AFT) and (U–Th)/He analysis in apatite (AHe) and zircon (ZHe), we evaluate the thermotectonic evolution of the Sul-Rio-Grandense Shield (SRGS), southernmost Mantiqueira Province, Brazil. Formed during the assembly of West Gondwana (Neoproterozoic), the shield comprises four tectonostratigraphic terranes separated by regional faults and shear zones. The central and eastern terranes present Mesozoic AFT ages, whereas the western terrane ages are mostly late Paleozoic. AHe ages show considerable dispersion, although most are Mesozoic. ZHe ages from the east are early Permian, whereas the west presents Devonian ages. Inverse thermal modelling indicates a Devonian to Carboniferous cooling phase in the west, time correlated with orogenies occurring at the SW margin of Gondwana, which affected the regional geodynamics and are possibly linked to limited uplift of the shield. From the Permian to Jurassic a major cooling phase took place in the SRGS, probably related to lithosphere thinning and uplift preceding the South Atlantic rifting. Samples closer to the Atlantic coast suggest a subtle reheating after this event, provisionally linked to a geothermal disturbance related to ocean opening and associated magmatism. A final post-Paleocene cooling phase towards surface conditions affected the entire SRGS.

Original language	English
Pages (from-to)	1056-1075
Number of pages	20
Journal	Journal of the Geological Society
Volume	176
Issue number	6
Early online date	23 Aug 2019
DOIs	https://doi.org/10.1144/jgs2019-018
Publication status	Published - Nov 2019

Bibliographical note

Acknowledgements
We thank P. W. Reiners and his team at the Baja Arizona Radiogenic Helium Dating Laboratory (USA) for the (U–Th)/He analyses and assistance. We are grateful for the suggestions of L. A. Hartmann and Chong Ma, which significantly improved the paper.
Funding
The authors gratefully acknowledge the support from Shell Brasil through the ‘BG05: UoA-UFRGS-SWB Sedimentary Systems’ project at UFRGS, the strategic importance of the support given by ANP through the R&D levy regulation, and the CNPq scholarship (SWE 204254/2017-5) during the exchange period at the University of Aberdeen.

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@article{d76c4e9ec9c24dc39ae3fb40b8dcb7e5,

title = "West Gondwana orogenies and Pangaea break-up: thermotectonic effects on the southernmost Mantiqueira Province, Brazil",

abstract = "Through the joint use of apatite fission tracks (AFT) and (U–Th)/He analysis in apatite (AHe) and zircon (ZHe), we evaluate the thermotectonic evolution of the Sul-Rio-Grandense Shield (SRGS), southernmost Mantiqueira Province, Brazil. Formed during the assembly of West Gondwana (Neoproterozoic), the shield comprises four tectonostratigraphic terranes separated by regional faults and shear zones. The central and eastern terranes present Mesozoic AFT ages, whereas the western terrane ages are mostly late Paleozoic. AHe ages show considerable dispersion, although most are Mesozoic. ZHe ages from the east are early Permian, whereas the west presents Devonian ages. Inverse thermal modelling indicates a Devonian to Carboniferous cooling phase in the west, time correlated with orogenies occurring at the SW margin of Gondwana, which affected the regional geodynamics and are possibly linked to limited uplift of the shield. From the Permian to Jurassic a major cooling phase took place in the SRGS, probably related to lithosphere thinning and uplift preceding the South Atlantic rifting. Samples closer to the Atlantic coast suggest a subtle reheating after this event, provisionally linked to a geothermal disturbance related to ocean opening and associated magmatism. A final post-Paleocene cooling phase towards surface conditions affected the entire SRGS.",

author = "{Silveira Luiz Machado}, {Joao Pacifico} and Jelinek, {Andrea Ritter} and Bicca, {Marcos Muller} and Randell Stephenson and Genezini, {Frederico Antonio}",

note = "Acknowledgements We thank P. W. Reiners and his team at the Baja Arizona Radiogenic Helium Dating Laboratory (USA) for the (U–Th)/He analyses and assistance. We are grateful for the suggestions of L. A. Hartmann and Chong Ma, which significantly improved the paper. Funding The authors gratefully acknowledge the support from Shell Brasil through the {\textquoteleft}BG05: UoA-UFRGS-SWB Sedimentary Systems{\textquoteright} project at UFRGS, the strategic importance of the support given by ANP through the R&D levy regulation, and the CNPq scholarship (SWE 204254/2017-5) during the exchange period at the University of Aberdeen.",

year = "2019",

month = nov,

doi = "10.1144/jgs2019-018",

language = "English",

volume = "176",

pages = "1056--1075",

journal = "Journal of the Geological Society ",

issn = "0016-7649",

publisher = "Geological Society of London",

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T2 - thermotectonic effects on the southernmost Mantiqueira Province, Brazil

AU - Silveira Luiz Machado, Joao Pacifico

AU - Jelinek, Andrea Ritter

AU - Bicca, Marcos Muller

AU - Stephenson, Randell

AU - Genezini, Frederico Antonio

N1 - Acknowledgements We thank P. W. Reiners and his team at the Baja Arizona Radiogenic Helium Dating Laboratory (USA) for the (U–Th)/He analyses and assistance. We are grateful for the suggestions of L. A. Hartmann and Chong Ma, which significantly improved the paper. Funding The authors gratefully acknowledge the support from Shell Brasil through the ‘BG05: UoA-UFRGS-SWB Sedimentary Systems’ project at UFRGS, the strategic importance of the support given by ANP through the R&D levy regulation, and the CNPq scholarship (SWE 204254/2017-5) during the exchange period at the University of Aberdeen.

PY - 2019/11

Y1 - 2019/11

N2 - Through the joint use of apatite fission tracks (AFT) and (U–Th)/He analysis in apatite (AHe) and zircon (ZHe), we evaluate the thermotectonic evolution of the Sul-Rio-Grandense Shield (SRGS), southernmost Mantiqueira Province, Brazil. Formed during the assembly of West Gondwana (Neoproterozoic), the shield comprises four tectonostratigraphic terranes separated by regional faults and shear zones. The central and eastern terranes present Mesozoic AFT ages, whereas the western terrane ages are mostly late Paleozoic. AHe ages show considerable dispersion, although most are Mesozoic. ZHe ages from the east are early Permian, whereas the west presents Devonian ages. Inverse thermal modelling indicates a Devonian to Carboniferous cooling phase in the west, time correlated with orogenies occurring at the SW margin of Gondwana, which affected the regional geodynamics and are possibly linked to limited uplift of the shield. From the Permian to Jurassic a major cooling phase took place in the SRGS, probably related to lithosphere thinning and uplift preceding the South Atlantic rifting. Samples closer to the Atlantic coast suggest a subtle reheating after this event, provisionally linked to a geothermal disturbance related to ocean opening and associated magmatism. A final post-Paleocene cooling phase towards surface conditions affected the entire SRGS.

AB - Through the joint use of apatite fission tracks (AFT) and (U–Th)/He analysis in apatite (AHe) and zircon (ZHe), we evaluate the thermotectonic evolution of the Sul-Rio-Grandense Shield (SRGS), southernmost Mantiqueira Province, Brazil. Formed during the assembly of West Gondwana (Neoproterozoic), the shield comprises four tectonostratigraphic terranes separated by regional faults and shear zones. The central and eastern terranes present Mesozoic AFT ages, whereas the western terrane ages are mostly late Paleozoic. AHe ages show considerable dispersion, although most are Mesozoic. ZHe ages from the east are early Permian, whereas the west presents Devonian ages. Inverse thermal modelling indicates a Devonian to Carboniferous cooling phase in the west, time correlated with orogenies occurring at the SW margin of Gondwana, which affected the regional geodynamics and are possibly linked to limited uplift of the shield. From the Permian to Jurassic a major cooling phase took place in the SRGS, probably related to lithosphere thinning and uplift preceding the South Atlantic rifting. Samples closer to the Atlantic coast suggest a subtle reheating after this event, provisionally linked to a geothermal disturbance related to ocean opening and associated magmatism. A final post-Paleocene cooling phase towards surface conditions affected the entire SRGS.

U2 - 10.1144/jgs2019-018

DO - 10.1144/jgs2019-018

M3 - Article

SN - 0016-7649

VL - 176

SP - 1056

EP - 1075

JO - Journal of the Geological Society

JF - Journal of the Geological Society

IS - 6

ER -

West Gondwana orogenies and Pangaea break-up: thermotectonic effects on the southernmost Mantiqueira Province, Brazil

Abstract

Bibliographical note

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