This award supports a study of molluscan fossils across the Cretaceous-Tertiary boundary on Seymour Island in the Antarctica Peninsula. Seymour Island contains rich and well preserved faunal and floral assemblages in a thick stratigraphic section that encompasses the Cretaceous-Tertiary boundary, a time of well documented extinction in other parts of the world. Previous work has yielded a rich molluscan fauna but additional work is needed to understand and correlate the biostratigraphy and sedimentology immediately above and below the Cretaceous-Tertiary transition. This work will attempt to recover fossils and examine the sedimentology on a centimeter sampling scale from 5 meters below to 5 meters above the boundary. These fossils, in conjunction with sedimentologic analysis of the measured section, will allow a determination of the continuity of the boundary section and will also allow an attempt at high resolution analysis of the molluscan faunal changes. This study will lead to an improved understanding of molluscan changes at the Cretaceous-Tertiary transition in high southern latitudes and the relation of these changes to Cretaceous- Tertiary extinction elsewhere.