Geology of hill end trough Molong high: A critical appraisal of the tectonic history of the hill end trough and its margins

Abstract

The Hill End Trough was a mid-Silurian to mid-Devonian depositional basin (Packham, 1960, 1969a), elongated north-south and flanked to the west by the Molong High and to the east by the Capertee High. The infill of the northern Hill End Trough is preserved mainly within the Hill End Synclinorium, a structure bounded on the west by the Copperhannia Fault Zone and on the east by the Wiagdon Fault Zone (Fig. 1). Similarly, the rocks of the former Molong and Capertee Highs are preserved largely within the Molong and Capertee Anticlinoria. The tectonic history of the Hill End Trough and its marginal highs (Fig. 2) can be considered in three time spans: 1. Early, volcanic-arc phase, prior to formation of the Hill End Trough (500 to 435 m.y.); 2. Birth and life of the Hill End Trough as an active interarc basin (435 to 380 m.y.); 3. Sedimentary infilling and terminal deformation (380 to 350 m.y.).