Research Interests

As a marine geologist and paleoceanographer I have aimed my research at unraveling the evolution of the global environment and biota during the Cenozoic Era (the last 65 million years) and processes that caused this change. Using Antarctica as a focus, colleagues and I have demonstrated close coupling between changes in the lithosphere (plate tectonics), ocean (paleoceanography), atmosphere (climate), cryosphere (ice sheets), and biosphere (marine and terrestrial life). I conceived the hypothesis that the development and expansion of the Circum-Antarctic Current during the Cenozoic thermally isolated the Antarctic Continent and caused formation of its ice sheets and cooling of the deep ocean. This demonstrated the importance of the opening and closing of oceanic gateways in directing environmental evolution of the planet. My work, with colleagues, has led to the discovery of major climatic and oceanographic changes associated with several epoch boundaries, thus explaining their placement within the geologic timescale. This helped tie global stratigraphy with modern paleoceanography, explaining the basis of classical stratigraphy itself. My more recent work is involved with the documentation and understanding of the cause of very rapid climatic changes during our present ice age (Quaternary), with emphasis on extraordinary marine sedimentary records of the California margin.

Membership Type


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Primary Section

Section 15: Geology

Secondary Section

Section 16: Geophysics