Lithostratigraphy and tectonic evolution of contrasting greenstone successions in the central Yilgarn Craton, Western Australia

Lithostratigraphy of the Late Archaean Marda-Diemals greenstone belt in the Southern Cross Terrane, central Yilgam Craton defines a temporal change from mafic volcanism to felsic-intermediate volcanism to clastic sedimentation. A ca. 3.0 Ga lower greenstone succession is characterised by malic volcanic rocks and banded iron-formation (BIF). It is subdivided into three lithostratigraphic associations and unconformably overlain by the ca. 2.73 Ga upper greenstone succession of calc-alkaline volcanic (Marda Complex) and clastic sedimentary rocks (Diemals Formation). D-1 north-south, low-angle thrusting was restricted to the lower greenstone succession and preceded deposition of the upper greenstone succession. D-2 east-west, orogenic compression ca. 2730-2680 Ma occurred in two stages; an earlier folding phase and a late phase that resulted in deposition and deformation of the Diernals Formation. Progressive and inhomogeneous east-west shortening ca. 2680-2655 Ma (D-3) produced regional-scale shear zones and arcuate structures. The lithostratigraphy and tectonic history of the Marda-Diemals greenstone belt are broadly similar to the northern Murchison Terrane in the western Yilgam Craton, but has older greenstones and deformation events than the southern Eastern Goldfields Terrane of the eastern Yilgam Craton. This indicates that the Eastern Goldfields Terrane may have accreted to an older Murchison-Southern Cross granite-greenstone nucleus. Crown Copyright (C) 2003 Published by Elsevier B.V. All rights reserved.