Geochronology of Massif-Type Anorthosites from the Ubendian Belt, Tanzania

Authors

  • Nelson Boniface

Keywords:

Ubendian Belt, massif-type Anorthosites, U-Pb zircon ages

Abstract

Massif-type anorthosites occur in East Africa at the margins of the Tanzania Craton in the Ubendian Belt. The massif assemblage constitutes of mafic-composition plutons (meta-anorthosite and meta-gabbro), ultramafic plutons, and titaniferous iron-ore. Silicic ortho-gneisses (tonalitic, dioritic, and granodioritic intrusives) also occur in the vicinity of the said massif-type anorthosites. This article presents ages of meta-anorthosites and meta-gabbros. The new U-Pb zircon age indicates that meta-gabbros and meta-anorthosites crystallized between 1915 ± 24 and 1905 ± 24 Ma concomitantly with the silicic magmatic bodies. Geochronological databases indicate that the period between 1920 and 1850 Ma HP-LT metamorphic interface was formed at subduction zone settings in the Ubendian Belt along with emplacement of arc related voluminous batholiths and volcanic rocks. The subduction tectonics was probably a driving engine for magmatism in the region. A Neoproterozoic metamorphic event dated at 547 ± 25 Ma reworked the Ubendian Belt massifs-type anorthosites.

Keywords: Ubendian Belt; massif-type Anorthosites; U-Pb zircon ages

☍ View Article Analytics

Downloads

Published

2020-06-30

Issue

Vol. 46 No. 2 (2020)

Section

Articles

License

Authors who publish in The Eastern Africa Law Review retain the copyright to their work and grant the University of Dar es Salaam a non-exclusive license to publish, reproduce, and distribute the article.

This article is published under the Creative Commons Attribution 4.0 International (CC BY 4.0) License, which permits unrestricted use, distribution, adaptation, and reproduction in any medium, provided the original work is properly cited.