Geological Setting

The geology of the field area consists of PreCambrian and Lower Palaeozoic folded metasedimentary rocks. The oldest unit, the Nimrod Group, is at least 1000 Ma old and is made up of schist, gneiss, marble and dolomite. This is overlain unconformably by the mainly terrigenous sediments of the PreCambrian Beardmore Group. These in turn are overlain unconformably by Cambrian carbonates of the Byrd Group. Numerous granitic plutons of the Granite Harbour Intrusives have intruded these three group (Gunner, in press). These basement rocks are unconformably overlain by the Devonian-Triassic Beacon Supergroup which is composed of glacial, alluvial and Shallow marine strata. These are intruded by numerous sills of the Jurassic Ferrar Dolerite which in places passes upwards into the Kirkpatrick Basalt. Sample localities are shown in Fig. 4.