ABSTRACT A newly constructed composite oxygen isotope record is a proxy for eustasy that extends back to the Cretaceous–Tertiary boundary and provides an independent test of sequence stratigraphic–based eustatic curves. The isotope record shows several eustatic episodes that are consistent with the geo- logical record of ice-sheet evolution. The first evidence for the existence of an ice sheet in East Antarctica occurs near the lower–middle Eocene boundary (base of the Lutetian stage). There is no evidence for a large ice sheet on Antarctica prior to this time; however, strata of this age are lacking over most of the continent. The iso- tope curve also indicates that the ice sheet experi- enced phases of growth during the late Eocene and middle Oligocene, followed by a decrease in vol- ume in the early Miocene. The Ross Sea stratigraphic record indicates initial evolution of the West Antarctica ice sheet during the early Miocene. By the middle Miocene, the ice sheet spread across the Ross Sea, Weddell Sea, and Antarctic Peninsula continental shelves. The Pliocene–Pleistocene record of glaciation in Antarctica includes numerous glacial erosion sur- faces on the continental shelf, indicating repeated advance and retreat of both East and West Antarctica ice sheets. These volume changes in the Antarctica ice sheet were in response to the rise and fall of sea level caused by expanding and con- tracting Northern Hemisphere ice sheets. There is a reasonable correlation between eustat- ic curves derived from sequence stratigraphic stud- ies and the composite oxygen isotope record since the middle Eocene. This correlation indicates that glacial eustasy has been the principal factor regulat- ing stratal stacking patterns on a global scale since the middle Eocene. INTRODUCTION A significant portion of the Earth’s stratigraphic record bears evidence for continental glaciation. Major glacial episodes occurred during the late Precambrian, early Paleozoic (Saharan Glaciation), late Paleozoic (Gondwana Glaciation), and Cen- ozoic. Each glacial episode was different because of the distribution of continents and, therefore, of ice sheets. Of particular importance is the extent of terrestrial ice sheets in lower latitudes; subpolar to temperate ice sheets are more responsive to high- frequency climatic changes, hence causing high- frequency sea level oscillations. These glacial episodes are manifested in the global stratigraphic record by strong cyclicity and by complex strati- graphic and facies relationships. A reasonable generalization in most basin set- tings is that subsidence rates are slower than the rate of glacial eustatic oscillation. Thus, glacial eustasy can predominantly regulate stratigraphic architecture (i.e., creation of accommodation space). This assumption implies that sequences are likely to be global in scale during glacial episodes. In contrast, stratal stacking patterns in nonglacial intervals may be more strongly regulated by other factors, such as climate and tectonism, which are more regional in scale. Thus, an improved record of glaciation provides a stronger basis for global sequence stratigraphic interpretations. Nearly 20 yr have passed since Vail et al. (1977) published their sequence stratigraphic results indi- cating third-order sea level fluctuations extending back in time far beyond when ice sheets were thought to exist. Since 1977, more detailed sequence stratigraphic studies have revealed third-order 1385 ©Copyright 1998. The American Association of Petroleum Geologists. All rights reserved. 1 Manuscript received October 8, 1996; revised manuscript received May 9, 1997; final acceptance February 5, 1998. 2 Rice University, Department of Geology and Geophysics, Houston, Texas 77005-1892. We would like to express our gratitude to Peter Vail, Jan Hardenbol, Geoffrey Haddad, and Andre Droxler for suggestions and discussions during the preparation of this paper. Special thanks to Emoke Vakarcs, Stephanie Shipp, Gabor Vakarcs, and Gerald Baum for reviewing early versions of the manuscript. Thanks also to Nicholas Christie-Blick, whose review greatly improved the original work. Glacial Eustasy During the Cenozoic: Sequence Stratigraphic Implications 1 Vitor S. Abreu and John B. Anderson 2 AAPG Bulletin, V. 82, No. 7 (July 1998), P. 1385–1400.