Evolution of the Mozambique Belt in Malawi constrained by granitoid U-Pb, Sm-Nd and Lu-Hf isotopic data

Manda, Blackwell W.C.; Cawood, Peter A.; Spencer, Christopher J.; Prave, Tony; Robinson, Ruth; Roberts, Nick M.W.. 2019 Evolution of the Mozambique Belt in Malawi constrained by granitoid U-Pb, Sm-Nd and Lu-Hf isotopic data. Gondwana Research, 68. 93-107. 10.1016/j.gr.2018.11.004

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Official URL: http://dx.doi.org/10.1016/j.gr.2018.11.004

Abstract/Summary

U-Pb, Sm-Nd and Lu-Hf isotopic data for granitoid rocks fromsouthernMalawi provide constraints on the timing and sources of magmatic activity within this segment of the Mozambique Belt and its role in the Rodinia and Gondwana supercontinent cycles. LA-ICP-MS single zircon U-Pb ages indicate a number of periods of magmatic activity: lateMesoproterozoic at ca. 1130Ma, 1070Ma, and 1050 to 1030Ma; Neoproterozoic at ca. 960Ma and 600Ma; Cambrian at ca. 530 and 515Ma, and Mesozoic at ca. 120 Ma. The oldest igneous activity, 1128±30Ma, correspondswith emplacement of a charnockitic granitoid in the southeast corner of Malawi (Mulanje area). This region subsequently experienced metamorphismdated at 515 ±18Ma. The youngest magmatism is alkaline in affinity and is associated with the East African Rift. Radiogenic isotope data indicate that the Mesoproterozoic samples have positive ɛNd and ɛHf values, signifying derivation from materialwith a suprachondritic signature, whereas the younger rocks have negative values suggestive of crustal material recycling and mixing for their source and origins. The data imply that in the Malawi region of the Mozambique Belt, addition of new crust occurred during Rodinia assembly whereas magmatic activity during Gondwana assembly was restricted to reworking and mixing.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1016/j.gr.2018.11.004
ISSN:	1342937X
Date made live:	16 Aug 2019 10:11 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/524792

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1016/j.gr.2018.11.004

ISSN:

1342937X

Date made live:

16 Aug 2019 10:11 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/524792