Paleoenvironmental interpretations and systematics of Devonian trace fossils from the Taylor Group (lower Beacon Supergroup), Antarctica

Abstract

Abstract Trace fossils are varied and abundant in the otherwise unfossiliferous Taylor Group sandstones of the lower Beacon Supergroup. Twenty-four ichnotaxa are recognised, many previously unrecorded, and these have been grouped into 7 ichnocoenoses that occur successively from the basal Windy Gully Sandstone up into the Aztec Siltstone. The trace fossils suggest that the earliest Taylor Group sediments, the New Mountain Subgroup, is a marine transgressive sequence that progressively buried an irregular Kukri Erosion Surface and which eventually overwhelmed all basement highs by the end of Altar Mountain Sandstone deposition. Both the Windy Gully Sandstone and the New Mountain Sandstone are interpreted as the nearshore deposits of wide sandy tidal bays in which bioturbation by crustaceans was intense, while trough cross-bedded channel sands bear numerous trackways of large walking arthropods. The intervening Terra Cotta Siltstone is probably the deposit of a coastal lagoon with variable salinity and a fa...