40Ar/39Ar dating of 1.0-1.1 Ga magnetizations from the São Francisco and Kalahari cratons: tectonic implications for Pan-African and Brasiliano mobile belts

Paul R. Renne; Tullis C. Onstott; Manoel S. D'Agrella-Filho; Igor G. Pacca; Wilson Teixeira

doi:10.1016/0012-821X(90)90165-T

⁴⁰Ar/³⁹Ar dating of 1.0-1.1 Ga magnetizations from the São Francisco and Kalahari cratons: tectonic implications for Pan-African and Brasiliano mobile belts

Paul R. Renne, Tullis C. Onstott, Manoel S. D'Agrella-Filho, Igor G. Pacca, Wilson Teixeira

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100 Scopus citations

Abstract

Paleomagnetic poles from 1.1-1.0 Ga dyke swarms in eastern Brazil (São Francisco Craton) are compared with 1.0 Ga poles from granulites of the Namaqua Province in southern Africa (Kalahari Graton). The intrusive ages of dykes are estimated from ⁴⁰Ar/³⁹Ar dating of outgassed biotites from baked country rocks. The age of magnetization for the granulites is derived by combining ⁴⁰Ar/³⁹Ar hornblende and biotite dates. When restored to a Mesozoic pre-drift configuration the paleomagnetic poles are in crude spatial agreement but are temporally discordant. To satisfy both paleomagnetic and geochronologic constraints, a reconstruction involving separation of the São Francisco and Kalahari cratons is required, indicating that the intervening Pan-African (Brasiliano) mobile belt may record a craton-craton collision.

Original language	English (US)
Pages (from-to)	349-366
Number of pages	18
Journal	Earth and Planetary Science Letters
Volume	101
Issue number	2-4
DOIs	https://doi.org/10.1016/0012-821X(90)90165-T
State	Published - Dec 1990

All Science Journal Classification (ASJC) codes

Geophysics
Geochemistry and Petrology
Earth and Planetary Sciences (miscellaneous)
Space and Planetary Science

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10.1016/0012-821X(90)90165-T

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@article{767059bb93e443b59d2596df48211686,

title = "40Ar/39Ar dating of 1.0-1.1 Ga magnetizations from the S{\~a}o Francisco and Kalahari cratons: tectonic implications for Pan-African and Brasiliano mobile belts",

abstract = "Paleomagnetic poles from 1.1-1.0 Ga dyke swarms in eastern Brazil (S{\~a}o Francisco Craton) are compared with 1.0 Ga poles from granulites of the Namaqua Province in southern Africa (Kalahari Graton). The intrusive ages of dykes are estimated from 40Ar/39Ar dating of outgassed biotites from baked country rocks. The age of magnetization for the granulites is derived by combining 40Ar/39Ar hornblende and biotite dates. When restored to a Mesozoic pre-drift configuration the paleomagnetic poles are in crude spatial agreement but are temporally discordant. To satisfy both paleomagnetic and geochronologic constraints, a reconstruction involving separation of the S{\~a}o Francisco and Kalahari cratons is required, indicating that the intervening Pan-African (Brasiliano) mobile belt may record a craton-craton collision.",

author = "Renne, {Paul R.} and Onstott, {Tullis C.} and D'Agrella-Filho, {Manoel S.} and Pacca, {Igor G.} and Wilson Teixeira",

note = "Funding Information: We thank A. Pedreira and A.K. Kneedler for assistancew ith fieldwork and mineral separations, J.K.W. Lee, C.-H. Lo and M. Debiche for assistance with computer programs for thermal modelling/Ar diffusion, 4°Ar/39Ar data analysis and tectonic reconstruction(sr espectively)R, .B. Har-graves for critical comments and discussionsa, nd S.M. Swapp for assistancew ith electron microprobe analysis. We appreciatea n anonymous reviewer'sc onstructivceo mmentsa, nd Kevin Burke's effusive punditry regarding the manuscript. This research was funded by the U.S. NSF (grants EAR-8451696 and EAR-8805529) and by the Brazilian CNPq, FAPESP and FINEP. This work is contribution No. 21 of the IGCP 257 {"}Precambrian Dyke Swarms{"}.",

year = "1990",

month = dec,

doi = "10.1016/0012-821X(90)90165-T",

language = "English (US)",

volume = "101",

pages = "349--366",

journal = "Earth and Planetary Science Letters",

issn = "0012-821X",

publisher = "Elsevier B.V.",

number = "2-4",

}

⁴⁰Ar/³⁹Ar dating of 1.0-1.1 Ga magnetizations from the São Francisco and Kalahari cratons: tectonic implications for Pan-African and Brasiliano mobile belts. / Renne, Paul R.; Onstott, Tullis C.; D'Agrella-Filho, Manoel S. et al.
In: Earth and Planetary Science Letters, Vol. 101, No. 2-4, 12.1990, p. 349-366.

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

TY - JOUR

T1 - 40Ar/39Ar dating of 1.0-1.1 Ga magnetizations from the São Francisco and Kalahari cratons

T2 - tectonic implications for Pan-African and Brasiliano mobile belts

AU - Renne, Paul R.

AU - Onstott, Tullis C.

AU - D'Agrella-Filho, Manoel S.

AU - Pacca, Igor G.

AU - Teixeira, Wilson

N1 - Funding Information: We thank A. Pedreira and A.K. Kneedler for assistancew ith fieldwork and mineral separations, J.K.W. Lee, C.-H. Lo and M. Debiche for assistance with computer programs for thermal modelling/Ar diffusion, 4°Ar/39Ar data analysis and tectonic reconstruction(sr espectively)R, .B. Har-graves for critical comments and discussionsa, nd S.M. Swapp for assistancew ith electron microprobe analysis. We appreciatea n anonymous reviewer'sc onstructivceo mmentsa, nd Kevin Burke's effusive punditry regarding the manuscript. This research was funded by the U.S. NSF (grants EAR-8451696 and EAR-8805529) and by the Brazilian CNPq, FAPESP and FINEP. This work is contribution No. 21 of the IGCP 257 "Precambrian Dyke Swarms".

PY - 1990/12

Y1 - 1990/12

N2 - Paleomagnetic poles from 1.1-1.0 Ga dyke swarms in eastern Brazil (São Francisco Craton) are compared with 1.0 Ga poles from granulites of the Namaqua Province in southern Africa (Kalahari Graton). The intrusive ages of dykes are estimated from 40Ar/39Ar dating of outgassed biotites from baked country rocks. The age of magnetization for the granulites is derived by combining 40Ar/39Ar hornblende and biotite dates. When restored to a Mesozoic pre-drift configuration the paleomagnetic poles are in crude spatial agreement but are temporally discordant. To satisfy both paleomagnetic and geochronologic constraints, a reconstruction involving separation of the São Francisco and Kalahari cratons is required, indicating that the intervening Pan-African (Brasiliano) mobile belt may record a craton-craton collision.

AB - Paleomagnetic poles from 1.1-1.0 Ga dyke swarms in eastern Brazil (São Francisco Craton) are compared with 1.0 Ga poles from granulites of the Namaqua Province in southern Africa (Kalahari Graton). The intrusive ages of dykes are estimated from 40Ar/39Ar dating of outgassed biotites from baked country rocks. The age of magnetization for the granulites is derived by combining 40Ar/39Ar hornblende and biotite dates. When restored to a Mesozoic pre-drift configuration the paleomagnetic poles are in crude spatial agreement but are temporally discordant. To satisfy both paleomagnetic and geochronologic constraints, a reconstruction involving separation of the São Francisco and Kalahari cratons is required, indicating that the intervening Pan-African (Brasiliano) mobile belt may record a craton-craton collision.

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UR - http://www.scopus.com/inward/citedby.url?scp=0025631460&partnerID=8YFLogxK

U2 - 10.1016/0012-821X(90)90165-T

DO - 10.1016/0012-821X(90)90165-T

M3 - Article

AN - SCOPUS:0025631460

SN - 0012-821X

VL - 101

SP - 349

EP - 366

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

IS - 2-4

ER -

⁴⁰Ar/³⁹Ar dating of 1.0-1.1 Ga magnetizations from the São Francisco and Kalahari cratons: tectonic implications for Pan-African and Brasiliano mobile belts

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