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The recovery of a small Early to Middle Llandovery (Early Silurian) conodont fauna from core samples in two wells (WMC Acacia 1 and WMC Boab 1) is the first documentation of Silurian rocks in the Canning Basin. The recovery of Ozarkodina hassi from both wells allows correlation of this fauna with the Rhuddanian to Aeronian Stages (Early to Middle Llandovery), which equates with the acuminatus Zone to sedgwickii Zone graptolite faunas. The samples are from a stratigraphic unit defined as the Lower Carbonate Member of the Worral Formation, but lithologic characteristics and age constraints indicate that the lower portion of this carbonate is part of the underlying Sahara Formation, the uppermost unit of the Carribuddy Group. The overlying Worral Formation (restricted) is of late Early to Middle Devonian (Emsian-Eifelian) age. This relationship has implications for the resource potential of the Canning Basin.

The major basement components within the Albany 1:1M Sheet area of southwestern Western Australia are defined from aeromagnetic anomalies and 10-40 km wavelength gravity anomalies, and are integrated with mapped geology to provide a geological model. Their structure (lithological banding), faults and dykes are determined from short-wavelength magnetic anomalies. The main tectonic elements are the Archaean Yilgarn Craton, the younger Albany Province to the south, and the Perth Basin with Proterozoic basement to the west. The Yilgarn Craton comprises an eastern zone with strike-extensive sinuous anomalies, typical of granite-greenstone terrane, and a western zone with sparse, short anomalies, characteristic of granite-gneiss terrane. Highly magnetised granulites along the eastern margin of the western zone correlate with outcrop of the Jimperding Metamorphic Belt in the north of the sheet. The eastern boundary of these granulites is parallel to a weak gravity gradient, and corresponds with a significant change in structural style; it is inferred to be a major intra-cratonic discontinuity. A north-northwest-trending gravity gradient within the western zone coincides with the Southwest Seismic Zone, and defines the eastward extent of thick, relatively dense crust defined by earlier studies of seismic refraction data. The Albany Province consists of a low-density southern zone with weakly sinuous magnetic banding, and a northern zone characterised by high-density, high-magnetisation, and linear magnetic banding. The southern margin of the Yilgarn Craton has been deformed for up to 50 km and demagnetised up to 20 km from the boundary. This deformation is inferred to have been caused by overthusting of the Albany Province during the Mid-Proterozoic. Subsequently, tectonism involving the Proterozoic crust beneath the Perth Basin deformed the western edge of the Yilgarn Craton and folded adjacent parts of the Albany Province southward. Greenstone and metamorphic belts are highly prospective and host many of the regions mineral deposits. Both the composition and geophysical characteristics of these belts contrast with those of more widespread granite and granite-gneiss terrane, which are of considerably lower economic interest. Analysis of the regional geophysical data sets in co njunction with outcrop geology leads to a more complete model of the Precambrian geology of the region than that derived from outcrop mapping alone.