South Atlantic passive margin evolution: A thermochronology case study from the Rio de Janeiro-Três Rios section, SE Brazil

Julia Gezatt; David MacDonald; Randell Stephenson; Andrea Ritter Jelinek; Andrew Carter

doi:10.1016/j.jsames.2020.103051

South Atlantic passive margin evolution: A thermochronology case study from the Rio de Janeiro-Três Rios section, SE Brazil

Julia Gezatt^*, David MacDonald, Randell Stephenson, Andrea Ritter Jelinek, Andrew Carter

^*Corresponding author for this work

Geology and Geophysics

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

5 Citations (Scopus)

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Abstract

The southeastern Brazilian passive margin records a complex post-rift evolution, with two parallel high-elevation features formed after the opening of the South Atlantic. We applied apatite fission track (AFT) and U-Th/He (AHe) low temperature thermochronology to constrain the thermo-tectonic history of the Serra do Mar escarpment in the area of Rio de Janeiro state. New AFT central ages for basement areas collected from a N-S transect orthogonal to the shoreline between the cities of Rio de Janeiro and Três Rios, range between 98.5 ± 5.3 and 54.1 ± 4.2 Ma, with mean track lengths between 12.34 ± 0.40 and 14.63 ± 0.17 μm. Uncorrected AHe ages lie between 68.1 ± 5.9 and 60.2 ± 7.3 Ma and are consistent with AFT results. Inverse thermal history models constrained by AFT and AHe data imply the earliest cooling onset from the Barremian (Early Cretaceous), with steady rates more common for samples closer to coastal areas. Maximum depths of denudation are between 2.5 and 4.5 km. Published thermochronological data from adjacent areas combined with the new results show a seemingly simpler post-rift evolution for the area, although suggesting structural control of age distribution and exhumation.

Original language	English
Article number	103051
Number of pages	14
Journal	Journal of South American Earth Sciences
Volume	106
Early online date	24 Nov 2020
DOIs	https://doi.org/10.1016/j.jsames.2020.103051
Publication status	Published - Mar 2021

Bibliographical note

We gratefully acknowledge support from Shell Brazil through the BG05: UoA-UFRGS-SWB Sedimentary Systems project at the University of Aberdeen and UFRGS, and the strategic importance of the support given by ANP through the RandD levy regulation. CNPq process number 237726/2012-2 for funding under regime GDE of the Science Without Borders Programme. We would also like to thank the London Geochronology Centre for access to their analytical facilities, welcome and assistance. We are grateful to Kerry Gallagher for the advice on the thermal modelling, and to Mark Wildman for the discussions. Finally, we thank the two reviewers for their constructive suggestions that have led to improvements in the final version of the manuscript.

Keywords

Fission track
(U–Th)/He
Passive margin
Thermal history modelling
Southeastern Brazil
Thermochronology
POSTRIFT REACTIVATION
LANDSCAPE EVOLUTION
(U-Th)/He
BREAK-UP
THERMOTECTONIC HISTORY
FISSION-TRACK ANALYSIS
SOUTHEASTERN BRAZIL
CONTINENTAL-MARGIN
APATITE (U-TH)/HE
AMERICAN PLATFORM
TECTONIC EVOLUTION

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Cite this

@article{05c8a4f0903242a9bf97ce15d24c74bf,

title = "South Atlantic passive margin evolution: A thermochronology case study from the Rio de Janeiro-Tr{\^e}s Rios section, SE Brazil ",

abstract = "The southeastern Brazilian passive margin records a complex post-rift evolution, with two parallel high-elevation features formed after the opening of the South Atlantic. We applied apatite fission track (AFT) and U-Th/He (AHe) low temperature thermochronology to constrain the thermo-tectonic history of the Serra do Mar escarpment in the area of Rio de Janeiro state. New AFT central ages for basement areas collected from a N-S transect orthogonal to the shoreline between the cities of Rio de Janeiro and Tr{\^e}s Rios, range between 98.5 ± 5.3 and 54.1 ± 4.2 Ma, with mean track lengths between 12.34 ± 0.40 and 14.63 ± 0.17 μm. Uncorrected AHe ages lie between 68.1 ± 5.9 and 60.2 ± 7.3 Ma and are consistent with AFT results. Inverse thermal history models constrained by AFT and AHe data imply the earliest cooling onset from the Barremian (Early Cretaceous), with steady rates more common for samples closer to coastal areas. Maximum depths of denudation are between 2.5 and 4.5 km. Published thermochronological data from adjacent areas combined with the new results show a seemingly simpler post-rift evolution for the area, although suggesting structural control of age distribution and exhumation.",

keywords = "Fission track, (U–Th)/He, Passive margin, Thermal history modelling, Southeastern Brazil, Thermochronology, POSTRIFT REACTIVATION, LANDSCAPE EVOLUTION, (U-Th)/He, BREAK-UP, THERMOTECTONIC HISTORY, FISSION-TRACK ANALYSIS, SOUTHEASTERN BRAZIL, CONTINENTAL-MARGIN, APATITE (U-TH)/HE, AMERICAN PLATFORM, TECTONIC EVOLUTION",

author = "Julia Gezatt and David MacDonald and Randell Stephenson and Jelinek, {Andrea Ritter} and Andrew Carter",

note = "We gratefully acknowledge support from Shell Brazil through the BG05: UoA-UFRGS-SWB Sedimentary Systems project at the University of Aberdeen and UFRGS, and the strategic importance of the support given by ANP through the RandD levy regulation. CNPq process number 237726/2012-2 for funding under regime GDE of the Science Without Borders Programme. We would also like to thank the London Geochronology Centre for access to their analytical facilities, welcome and assistance. We are grateful to Kerry Gallagher for the advice on the thermal modelling, and to Mark Wildman for the discussions. Finally, we thank the two reviewers for their constructive suggestions that have led to improvements in the final version of the manuscript. ",

year = "2021",

month = mar,

doi = "10.1016/j.jsames.2020.103051",

language = "English",

volume = "106",

journal = "Journal of South American Earth Sciences",

issn = "0895-9811",

publisher = "Elsevier BV",

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TY - JOUR

T1 - South Atlantic passive margin evolution

T2 - A thermochronology case study from the Rio de Janeiro-Três Rios section, SE Brazil

AU - Gezatt, Julia

AU - MacDonald, David

AU - Stephenson, Randell

AU - Jelinek, Andrea Ritter

AU - Carter, Andrew

N1 - We gratefully acknowledge support from Shell Brazil through the BG05: UoA-UFRGS-SWB Sedimentary Systems project at the University of Aberdeen and UFRGS, and the strategic importance of the support given by ANP through the RandD levy regulation. CNPq process number 237726/2012-2 for funding under regime GDE of the Science Without Borders Programme. We would also like to thank the London Geochronology Centre for access to their analytical facilities, welcome and assistance. We are grateful to Kerry Gallagher for the advice on the thermal modelling, and to Mark Wildman for the discussions. Finally, we thank the two reviewers for their constructive suggestions that have led to improvements in the final version of the manuscript.

PY - 2021/3

Y1 - 2021/3

N2 - The southeastern Brazilian passive margin records a complex post-rift evolution, with two parallel high-elevation features formed after the opening of the South Atlantic. We applied apatite fission track (AFT) and U-Th/He (AHe) low temperature thermochronology to constrain the thermo-tectonic history of the Serra do Mar escarpment in the area of Rio de Janeiro state. New AFT central ages for basement areas collected from a N-S transect orthogonal to the shoreline between the cities of Rio de Janeiro and Três Rios, range between 98.5 ± 5.3 and 54.1 ± 4.2 Ma, with mean track lengths between 12.34 ± 0.40 and 14.63 ± 0.17 μm. Uncorrected AHe ages lie between 68.1 ± 5.9 and 60.2 ± 7.3 Ma and are consistent with AFT results. Inverse thermal history models constrained by AFT and AHe data imply the earliest cooling onset from the Barremian (Early Cretaceous), with steady rates more common for samples closer to coastal areas. Maximum depths of denudation are between 2.5 and 4.5 km. Published thermochronological data from adjacent areas combined with the new results show a seemingly simpler post-rift evolution for the area, although suggesting structural control of age distribution and exhumation.

AB - The southeastern Brazilian passive margin records a complex post-rift evolution, with two parallel high-elevation features formed after the opening of the South Atlantic. We applied apatite fission track (AFT) and U-Th/He (AHe) low temperature thermochronology to constrain the thermo-tectonic history of the Serra do Mar escarpment in the area of Rio de Janeiro state. New AFT central ages for basement areas collected from a N-S transect orthogonal to the shoreline between the cities of Rio de Janeiro and Três Rios, range between 98.5 ± 5.3 and 54.1 ± 4.2 Ma, with mean track lengths between 12.34 ± 0.40 and 14.63 ± 0.17 μm. Uncorrected AHe ages lie between 68.1 ± 5.9 and 60.2 ± 7.3 Ma and are consistent with AFT results. Inverse thermal history models constrained by AFT and AHe data imply the earliest cooling onset from the Barremian (Early Cretaceous), with steady rates more common for samples closer to coastal areas. Maximum depths of denudation are between 2.5 and 4.5 km. Published thermochronological data from adjacent areas combined with the new results show a seemingly simpler post-rift evolution for the area, although suggesting structural control of age distribution and exhumation.

KW - Fission track

KW - (U–Th)/He

KW - Passive margin

KW - Thermal history modelling

KW - Southeastern Brazil

KW - Thermochronology

KW - POSTRIFT REACTIVATION

KW - LANDSCAPE EVOLUTION

KW - (U-Th)/He

KW - BREAK-UP

KW - THERMOTECTONIC HISTORY

KW - FISSION-TRACK ANALYSIS

KW - SOUTHEASTERN BRAZIL

KW - CONTINENTAL-MARGIN

KW - APATITE (U-TH)/HE

KW - AMERICAN PLATFORM

KW - TECTONIC EVOLUTION

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U2 - 10.1016/j.jsames.2020.103051

DO - 10.1016/j.jsames.2020.103051

M3 - Article

SN - 0895-9811

VL - 106

JO - Journal of South American Earth Sciences

JF - Journal of South American Earth Sciences

M1 - 103051

ER -

South Atlantic passive margin evolution: A thermochronology case study from the Rio de Janeiro-Três Rios section, SE Brazil

Abstract

Bibliographical note

Keywords

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