The Sylvania project area covers part of the Sylvania Inlier, an Archaean-aged cratonic block. The project is bordered to the north by the rocks of the Proterozoic Hamersley Basin which overlaps to the Archean-aged Pilbara Craton further to the north (Figure 8.0). The project is considered prospective for gold mineralisation and is relatively untested by systematic modern exploration techniques.
The Sylvania inlier is predominantly composed of granite-greenstone terrain, with the greenstone rocks comprising moderately metamorphosed mafic-ultramafic volcanic, clastic sediments, cherts and BIF. This greenstone stratigraphy is host to the Bibra and Francopan gold deposits on the southern margins of the inlier and the Jimblebar gold, copper and chromite mineralisation to the east.
The Hamersley Formation overlies the inlier with its eldest basal unit, the Fortescue Group, being in faulted contact. The group consist of typical basal clastic sediments and mafic volcanic rocks which are intruded by doleritic sills. The overlying Hamersley Group is highly prospective for iron ore mineralisation. Structurally, the Mt. Whaleback Fault and other regionally significant faults persist through the project area and the interaction of these with the Sylvania greenstone sequences is interpreted as being prospective for gold mineralisation.
Of particular interest is the recognised presence of conglomerate stratigraphy that is interpreted to be either part of the Hardy Formation or its lateral equivalent. Recent events across the Pilbara have identified this formation as being prospective for palaeo-placer gold mineralisation.
It is proposed that initial programs of exploration will involve mapping and sampling of this horizon.
Figure 8.0 Sylvania Project: Geology and noted gold anomalies