Stratigraphy of the Taylor and lower Victoria Groups (Beacon Supergroup) between the Mackay Glacier and Boomerang Range, Antarctica

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Abstract
The stratigraphy of the Taylor and basal Victoria Groups exposed over an area of 3500 km2 between the Boomerang Range and MacKay Glacier of southern Victoria Land is described, based upon data from 65 measured sections. The Taylor Group is of Devonian or older age and is at least 1400 m thick. It rests nonconformably, via the peneplained Kukri Erosion Surface, upon a crystalline basement complex of Ordovician and older rocks. The Taylor Group, composed largely of terrestrial quartzose sandstones. consists of the New Mountain Sandstone at the base, overlain by the Altar Mountain Formation, Arena Sandstone, Beacon Heights Orthoquartziite, and the Aztec Siltstone. The Terra Cotta Siltstone member of the New Mountain Sandstone, the Altar Mountain Formation, and the Aztec Siltstone contain cyclic red bed sequences. The New Mountain Sandstone is separated from the rest of the Taylor Group by the south and southwest trending Heimdall Erosion Surface. The diversity of the lower part of the Taylor Group contrasts with the homogenous and broadly equivalent Hatherton Sandstone and Alexandra Formation of the Beacon Supergroup elsewhere, suggesting paleogeographically distinct basins of sedimentation. The Permian to Triassic Victoria Group disconformably overlies the Taylor Group via the glacigene Maya Erosion Surface. Within the Victoria Group the basal Metschel Tillite is separated from the overlying Weller Coal Measures by the Pyramid Erosion Surface which in many localities has completely eroded the Metschel Tillite and cut down through the older Maya Erosion Surface.