In the Wright Valley and Taylor Glacier region of southern Victoria Land more than 5,000 feet of mid-Paleozoic to mid-Mesozoic sedimentary rocks of the Beacon Group overlie nonconformably a Precambrian to Lower Paleozoic basement. The rocks of the Beacon Group are mainly subgreywacke, arkose, and orthoquartzite. The oldest include dark subgreywacke breccia and conglomerate (Boreas Subgreywacke Member), and pink to grey arkose (Odin Arkose). An almost pure quartz sandstone (Beacon Heights Orthoquartzite) overlies the Odin Arkose and is the thickest and most widespread formation in this region. There follow in several localities a thin formation of red and green siltstone (Aztec Siltstone), and a younger formation of quartz sandstone, carbonaceous sandstone, siltstone, and shale (Weller Sandstone). Sedimentary features in these formations include massive bedding, cross bedding, cross lamination, alternating coloured beds, and desiccation polygons. Tracks, castings, and burrows of invertebrates are rare. Correlation with fossil localities adjacent to the area suggests that the Beacon Group in this region was deposited during the Devonian, Carboniferous, and possibly the Permian Periods. The rocks were laid down in fluvial, lacustrine, paludal, and aeolian environments.