Magneto-stratigraphic studies in Neogene deposits of Taylor Valley and McMurdo Sound, Antarctica

Magnetic polarity and susceptibility zonations obtained from drill cores have served to refine temporal correlations in glaciogenic sections cored in eastern Taylor Valley. The zonations have led to a better understanding of the glacial and structural history for an interval of time that extends from the late Miocene (about 7 m.y. ago) to perhaps near the end of the Pliocene (- 2.4 to 1.8 m.y.). However polarity data from a core drilled in McMurdo Sound (hole MSSTS-I) were found to be less useful. In this core, normal and reverse polarity deposits of Holocene, Pleistocene, and Pliocene age are nearly 40 m thick and appear to unconformably overlie strata assigned to the middle Miocene on the basis of a reworked fauna and flora. Gaps in the stratigraphic coverage of the Miocene strata, and two intervals in which the magnetisation post-dates deposition, however, have made development of a reliable polarity zonation impossible, and no firm correlation could be made with the magnetic polarity time scale.