GEOLOGICAL APPRAISAL OF THE MOOTWINGEE AREA, NEW SOUTH WALES

Abstract

The results of various photogeological, geological and geophysical programmes in the Mootwingee Area of northwestern New South Wales are discussed.

In a structurally complex area, a central horst of outcropping Precambrian rocks trends north-northwestwards. This is flanked both to the east and west by basins containing considerable thicknesses of Palaeozoic sediments.

The problem of whether the western structural basin, now represented by the Topar syncline, is coincident with the Cambro-Ordovician basin of sedimentation (?Bancannia Trough) is also discussed. The presence of infolded and down-faulted remnants of Cambro-Ordovician sediments within the Precanibrian basement, to the north of the area discussed, suggests that Cambro-Ordovician sedimentation may have extended further eastward than is now revealed in outcrop.

The main source-potential of the area appears to be confined to the Cambro-Ordovician sequence with perhaps very limited potential in the thick Devonian sediments. The drilling of a stratigraphic well in each of the basinal areas respectively to the west and east of the centrally-outcropping Precambrian block, appears justified. Such drilling should resolve some of the above-mentioned problems of depositional limits, as well as assist in evaluating the petroleum potential of the region.