Neogene stratigraphy of Taylor Valley, Transantarctic Mountains, Antarctica: Evidence for climate dynamism and a vegetated Early Pliocene coastline of McMurdo Sound

Abstract

Understanding of Neogene climate in Antarctica has been an intractable problem for over 20 years. Competing models of the effect of Pliocene climatic warmth have not yet been reconciled. New sedimentological and paleontological data from Dry Valley Drilling Project core (DVDP-10) demonstrate a dynamic climate regime for the early and mid-Pliocene record preserved in the floor of Taylor Valley. This succession of interbedded mudrocks, sandstones, conglomerates and diamictites includes evidence for times when the coastal plain landscape of Taylor Valley may have been vegetated by higher land plants. Biostratigraphic data from DVDP-10 are utilized to correlate to the more detailed and finely resolved record in the AND-1B core in southern McMurdo Sound. Accordingly, the interval in DVDP-10 that records dynamic environmental fluctuations with a possible vegetated coastal plain land system is bracketed at 4.92–4.25Ma. These data suggest that low altitude terrains of the Dry Valleys during the Early Pliocene were subjected to glacial-interglacial cycles in which some interglacials were largely ice-free.