Geochemical characterization of a reconstructed 1110 Ma Large Igneous Province

1110 Ma Large Igneous Province (LIP) fragments in the Kalahari craton, southern Africa (Umkondo LIP); Dronning Maud Land, Antarctica; Bundelkhand portion of Indian craton (Mahoba dolerite dykes); Congo craton (Huila-Epembe dolerite dykes); and Amazonia (Rincon del Tigre-Huanchaca LIP) have been reco...

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Bibliographic Details
Published in:Precambrian Research
Main Authors: Choudhary, Babita R., Ernst, Richard E., Xu, Yi-Gang, Evans, David A. D., de Kock, Michiel O., Meert, Joseph G., Ruiz, Amarildo S., Lima, Gabrielle A.
Format: Report
Language:English
Published: ELSEVIER 2019
Subjects:
Geology
Mesoproterozoic
Large Igneous Province
Geochemistry-reconstruction
1110 Ma dykes swarms
Umkondia
Geosciences
Multidisciplinary
DYKE SWARMS
KALAHARI CRATON
MAGMATIC EVENTS
CENTRAL INDIA
PLATE MOTION
2.5 GA
MANTLE
EVOLUTION
ETENDEKA
VOLCANISM
Dronning Maud Land
Indian
Tigre
Antarc*
Antarctica
Online Access:http://ir.gig.ac.cn/handle/344008/48875
https://doi.org/10.1016/j.precamres.2019.105382
Description
Summary:1110 Ma Large Igneous Province (LIP) fragments in the Kalahari craton, southern Africa (Umkondo LIP); Dronning Maud Land, Antarctica; Bundelkhand portion of Indian craton (Mahoba dolerite dykes); Congo craton (Huila-Epembe dolerite dykes); and Amazonia (Rincon del Tigre-Huanchaca LIP) have been reconstructed as a single LIP with plume centre beneath the NW part of the Kalahari Craton. This paper offers the best estimates for the paleoposition of the Indian and Amazonian cratons along with conjoined Kalahari-SF/Congo reconstruction. This 1110 Ma mafic magmatism is dominantly tholeiitic, ranging from basalt to andesitic basalt in composition, generated over a range of mantle melting depths [(Gd/Yb)N = 1.2-2.3], exhibit low to high contamination with crustal components (negative Nb anomalies, eNd (0 to -12), and elevated Th/Yb). The data fall into two Groups based on TiO2 content, with Group 1 (low Ti) of andesitic basalt composition, and Group 2 (high Ti) exhibiting a basaltic affinity. Group 1 magmas were generated in the spinel lherzolite field followed by significant contamination likely during passage through metasomatised lithospheric mantle in crustal magma chambers. A greater melting depth reaching into the garnet lherzolite field is proposed for the Group 2 magmas. The majority of Group 2 units are located in the Kalahari and Congo cratons, and this reflects onset of deeper melting closer to the interpreted plume axis in our reconstruction.

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