Geology of hill end trough Molong high: The stratigraphy and structure of the Upper Devonian rocks between Mt. Horrible and the Razorback Road, and the implications for the tectonics of NSW

Abstract

Recent mapping of Upper Devonian ? ?Early Carboniferous rocks north of Mt. Horrible reveals a coarsening-upwards sequence showing a complete regression from neritic to fluviatile and piedmont fan environments. The basal marine and littoral sediments consist of indurated quartz-rich (60?80%) arenites with some Cyrtospirifer horizons. The lower fluviatile sequence consists of quartz-rich arenites and red oligomictic conglomerates with rounded quartzite clasts. The upper fluviatile arenites and rudites have variable composition and poor sorting. The uppermost sediments are characterised by an increased proportion of lithic detritus (Fig. 3).