Dykes of the 1.11 Ga Umkondo LIP, Southern Africa: Clues to a complex plumbing system

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Dykes of the 1.11 Ga Umkondo LIP, Southern Africa: Clues to a complex plumbing system. / de Kocka, Michiel O.; Ernst, Richard; Söderlund, Ulf; Jourdan, Fred; Hofmann, Axel; Le Gall, Bernard; Bertrand, Herve; Chisonga, Benny C.; Beukes, Nicolas; Rajesh, H. M.; Moseki, L. M.; Fuchs, R.

In: Precambrian Research, Vol. 249, 2014, p. 129-143.

Research output: Contribution to journalArticle

Harvard

de Kocka, MO, Ernst, R, Söderlund, U, Jourdan, F, Hofmann, A, Le Gall, B, Bertrand, H, Chisonga, BC, Beukes, N, Rajesh, HM, Moseki, LM & Fuchs, R 2014, 'Dykes of the 1.11 Ga Umkondo LIP, Southern Africa: Clues to a complex plumbing system', Precambrian Research, vol. 249, pp. 129-143. https://doi.org/10.1016/j.precamres.2014.05.006

APA

de Kocka, M. O., Ernst, R., Söderlund, U., Jourdan, F., Hofmann, A., Le Gall, B., Bertrand, H., Chisonga, B. C., Beukes, N., Rajesh, H. M., Moseki, L. M., & Fuchs, R. (2014). Dykes of the 1.11 Ga Umkondo LIP, Southern Africa: Clues to a complex plumbing system. Precambrian Research, 249, 129-143. https://doi.org/10.1016/j.precamres.2014.05.006

CBE

de Kocka MO, Ernst R, Söderlund U, Jourdan F, Hofmann A, Le Gall B, Bertrand H, Chisonga BC, Beukes N, Rajesh HM, Moseki LM, Fuchs R. 2014. Dykes of the 1.11 Ga Umkondo LIP, Southern Africa: Clues to a complex plumbing system. Precambrian Research. 249:129-143. https://doi.org/10.1016/j.precamres.2014.05.006

MLA

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Author

de Kocka, Michiel O. ; Ernst, Richard ; Söderlund, Ulf ; Jourdan, Fred ; Hofmann, Axel ; Le Gall, Bernard ; Bertrand, Herve ; Chisonga, Benny C. ; Beukes, Nicolas ; Rajesh, H. M. ; Moseki, L. M. ; Fuchs, R. / Dykes of the 1.11 Ga Umkondo LIP, Southern Africa: Clues to a complex plumbing system. In: Precambrian Research. 2014 ; Vol. 249. pp. 129-143.

RIS

TY - JOUR

T1 - Dykes of the 1.11 Ga Umkondo LIP, Southern Africa: Clues to a complex plumbing system

AU - de Kocka, Michiel O.

AU - Ernst, Richard

AU - Söderlund, Ulf

AU - Jourdan, Fred

AU - Hofmann, Axel

AU - Le Gall, Bernard

AU - Bertrand, Herve

AU - Chisonga, Benny C.

AU - Beukes, Nicolas

AU - Rajesh, H. M.

AU - Moseki, L. M.

AU - Fuchs, R.

PY - 2014

Y1 - 2014

N2 - The Umkondo Large Igneous Province (LIP) is represented by widespread (similar to 2.0 x 10(6) km(2)) mafic intrusions that were rapidly emplaced (1112-1108 Ma) into the Kalahari craton of southern Africa and the formerly adjacent Grunehogna Province of Antarctica during Rodinia assembly. Very few Umkondo-aged dykes have been identified before, resulting in a poor understanding of this LIP's plumbing system and origin. Here we report six new similar to 1110 Ma U-Pb TIMS baddeleyite ages for various dolerite dykes, which, when coupled with geochemistry from some of the dykes, suggest association with the Umkondo LIP. The distribution of dykes defines distinct radiating swarms, which locate two separate magmatic centers on the northern margin of the Kalahari craton, and a third less robust center on the SE margin. The Umkondo intrusions' geochemistry indicates significant partial melting of the sub-continental mantle lithosphere (SCLM) and requires a transient thermal anomaly in the mantle. A viable model sees a mantle plume ascend beneath the craton and split into different portions that moved and ascended to different lithospheric thin-spots along the margins of the craton. As an alternative, the rise in mantle temperature associated with continental aggregation at this time is considered sufficient to cause partial melting of the SCLM without any plume involvement. Specific features of the Umkondo LIP's plumbing system are supportive of either model, and an approach of multiple working hypotheses is recommended. (C) 2014 Elsevier B.V. All rights reserved.

AB - The Umkondo Large Igneous Province (LIP) is represented by widespread (similar to 2.0 x 10(6) km(2)) mafic intrusions that were rapidly emplaced (1112-1108 Ma) into the Kalahari craton of southern Africa and the formerly adjacent Grunehogna Province of Antarctica during Rodinia assembly. Very few Umkondo-aged dykes have been identified before, resulting in a poor understanding of this LIP's plumbing system and origin. Here we report six new similar to 1110 Ma U-Pb TIMS baddeleyite ages for various dolerite dykes, which, when coupled with geochemistry from some of the dykes, suggest association with the Umkondo LIP. The distribution of dykes defines distinct radiating swarms, which locate two separate magmatic centers on the northern margin of the Kalahari craton, and a third less robust center on the SE margin. The Umkondo intrusions' geochemistry indicates significant partial melting of the sub-continental mantle lithosphere (SCLM) and requires a transient thermal anomaly in the mantle. A viable model sees a mantle plume ascend beneath the craton and split into different portions that moved and ascended to different lithospheric thin-spots along the margins of the craton. As an alternative, the rise in mantle temperature associated with continental aggregation at this time is considered sufficient to cause partial melting of the SCLM without any plume involvement. Specific features of the Umkondo LIP's plumbing system are supportive of either model, and an approach of multiple working hypotheses is recommended. (C) 2014 Elsevier B.V. All rights reserved.

KW - Mesoproterozoic

KW - Large Igneous Province

KW - Geochronology

KW - Rodinia

KW - Kalahari craton

KW - Dyke swarms

U2 - 10.1016/j.precamres.2014.05.006

DO - 10.1016/j.precamres.2014.05.006

M3 - Article

VL - 249

SP - 129

EP - 143

JO - Precambrian Research

JF - Precambrian Research

SN - 0301-9268

ER -