The Paleoproterozoic (ca. 2.0-1.8 Ga) UbendianUsagaran orogens surrounding the SE and SW margins of the Archaean Tanzania craton contain eclogites of MORBlike chemistry which are among the oldest eclogite occurrences exposed in orogenic belts on Earth. Our study of metamorphic events by petrology and U-Pb SHRIMP dating of zircons is aimed to unravel the orogenic history of the Ubendian Belt southwest of the Tanzania Craton