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

Michiel O. De Kock, Richard Ernst, Ulf Söderlund, Fred Jourdan, Axel Hofmann, Bernard Le Gall, Hervé Bertrand, Benny C. Chisonga, Nicolas Beukes, H. M. Rajesh, L. M. Moseki, R. Fuchs

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

The Umkondo Large Igneous Province (LIP) is represented by widespread (~2.0×106km2) mafic intrusions that were rapidly emplaced (1112-1108Ma) 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 ~1110Ma 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.

Original languageEnglish
Pages (from-to)129-143
Number of pages15
JournalPrecambrian Research
Volume249
DOIs
Publication statusPublished - Jan 1 2014

Fingerprint

Plumbing
large igneous province
Geochemistry
craton
Melting
mantle
partial melting
lithosphere
Agglomeration
geochemistry
Association reactions
baddeleyite
Rodinia
mantle plume
diabase
temperature anomaly
plume
Temperature
Southern Africa
temperature

All Science Journal Classification (ASJC) codes

  • Geology
  • Geochemistry and Petrology

Cite this

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

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

In: Precambrian Research, Vol. 249, 01.01.2014, p. 129-143.

Research output: Contribution to journalArticle

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T1 - Dykes of the 1.11Ga Umkondo LIP, Southern Africa

T2 - Clues to a complex plumbing system

AU - De Kock, Michiel O.

AU - Ernst, Richard

AU - Söderlund, Ulf

AU - Jourdan, Fred

AU - Hofmann, Axel

AU - Le Gall, Bernard

AU - Bertrand, Hervé

AU - Chisonga, Benny C.

AU - Beukes, Nicolas

AU - Rajesh, H. M.

AU - Moseki, L. M.

AU - Fuchs, R.

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De Kock MO, Ernst R, Söderlund U, Jourdan F, Hofmann A, Le Gall B et al. Dykes of the 1.11Ga Umkondo LIP, Southern Africa: Clues to a complex plumbing system. Precambrian Research. 2014 Jan 1;249:129-143. https://doi.org/10.1016/j.precamres.2014.05.006