New Permian-Jurassic deposits in the far North of Victoria Land, East Antarctica

Abstract

The geology of the Transantarctic Basin in the far north of Victoria Land is still poorly known. Joint Korean-Italian-German field work in the central Rennick Glacier area during the 2015-2016 season has yielded exciting new results. Based on lithology and fossil content, we recognize four distinct terrestrial sedimentary units in the area; in ascending order, (1) the Permian Takrouna Formation (thickness ~300 m) with common glossopterid remains; (2) a previously unknown unit (thickness 75+ m) mainly of reddish-weathering, commonly tabular-cross-bedded pebbly sandstone with intercalated siltstone and palaeosols, barren of body fossils but rich in trace fossils; (3) another previously unknown unit (thickness 250+ m) of olive-weathering fine-grained sandstone and thick overbank mudstone with palaeosols and thin coal seams, containing abundant silicified wood (Kykloxylon, Agathoxylon), silicified peat, and plant compressions (e.g., Heidiphyllum, Lepacyclotes) indicating a Triassic age; and (4) about 15 m of mainly conglomeratic trough-cross-bedded, medium- to coarse-grained quartzose sandstone similar to the Section Peak Formation (Rhaetian to Early Jurassic) further south. Our results reveal a much more complete Permian to Jurassic basin fill in that area than was previously thought; on-going palynological analyses should help clarify the precise stratigraphic relationships to better-known sections elsewhere in the Transantarctic Mountains and in Tasmania.