Field and petrographic descriptions of the outcrops of the McMurdo Volcanic Group in the Royal Society Ranges, northwest of the Koettlitz Glacier

Detailed field and petrographic observations of the outcrops of McMurdo Volcanics Group in the Southern Foothills of the Royal Society Range from Foster Crater in the south to Marshall Valley in the north (north-west of the Koettlitz Glacier) were completed. The areas investigated and described include Heald Island, Roaring Valley, Lower Radian Glacier, Pipecleaner Glacier to Radian Ridge, Rucker Ridge, the Miers Valley, the Garwood Valley, Chancellor Ridge (the area between the Howchin and Walcott Glaciers) and the Marshall Stream Delta. The Volcanics at Foster Centre (lying at the south-eastern end of Highway Ridge, immediately north of the confluence of the Foster and Koettlitz Glaciers) were also examined in detail to build on work conducted in an earlier season. Pre-glacial and post-glacial deposits were investigated. Samples were collected and petrographic descriptions were collected and some were analysed by x-ray diffraction. The samples from the Garwood Valley were mislaid and subsequently this site was resampled in the 1982/83 season. 20 samples were collected including 9 samples of very coarse grained amphibole-pyroxene-garnet-plagioclase rock formed as a skarn of altered iron rich calcareous rocks adjacent to gabbro.