Cratonwide Overlap Assemblage Shamvaian Group

The shamvaian Group consists of a sequence of coarse clastic rocks that overlie the upper Greenstones in several locations. These conglomerates, arkoses, and graywackes are well known from the Harare, Midlands, Masvingo, and Belingwe greenstone belts. The Cheshire Formation, the top unit of the Belingwe greenstone belt, consists of a heterogeneous succession of sedimentary rocks including conglomerate, sandstone, siltstone, argillite, limestone, cherty limestone, stromatolitic limestone, and minor banded iron formation. The shamvaian Group is intruded by the circa 2.6 billion-year-old Chilimanzi suite granites, providing an upper age limit on deposition. In the Bindura-Shamva greenstone belt the Shamvaian Group is 1.2 miles (2 km) thick, beginning with basal conglomerates and grading up into a thick sandstone sequence. Tonalitic clasts in the basal conglomerate have yielded igneous ages of 3.2, 2.9, 2.8, and 2.68 billion years. Felsic volcanics associated with the Shamvaian Group in several greenstone belts have ages of 2.66 to 2.64 billion years.

Was this article helpful?

0 0
The Basic Survival Guide

The Basic Survival Guide

Disasters: Why No ones Really 100 Safe. This is common knowledgethat disaster is everywhere. Its in the streets, its inside your campuses, and it can even be found inside your home. The question is not whether we are safe because no one is really THAT secure anymore but whether we can do something to lessen the odds of ever becoming a victim.

Get My Free Ebook

Post a comment