ABSTRACT: Cretaceous-Cenozoic Sequence Response to Eustasy and Tectonism on a Plate Margin / East Coast North Island, New Zealand

FIELD, BRAD, and CHRIS URUSKI, Department of Scientific and Industrial Research, Geology and Geophysics, Lower Hutt, New Zealand

The East Coast of the North Island was at a plate margin during most of the Cretaceous-Cenozoic and has been an active margin during most of the Neogene. This study attempts to provide a sequence stratigraphic key to assist interpretation of seismic data in areas with no well or outcrop control, and to enable more refined paleogeographic models to be developed for the region as part of a New Zealand basin studies program with a hydrocarbon exploration theme.

Key areas around two wells (Rere 1 and Hawke Bay 1) with reasonable quality seismic data were studied and, where possible, system tracts identified and compared with outcrop, well, and seismic data from other areas to check for regional vs. local effects. Sequence boundaries have been identified in the Albian (at least 3, possibly more based on earlier outcrop studies), Cenomanian (2+), Coniacian (1), Campanian (1), KT boundary, Ypresian (1), Chattian (2), Aquitanian (1), Serravalian (1), Tortonian (2), Messinian (2), and Pliocene (4+). International stages cited are based on the presently understood correlations of New Zealand stages with the northern hemisphere time scale.

This model is being tested through sedimentological studies and greater resolution of biostratigraphy and paleobathymetry estimates form well and outcrop studies.

AAPG Search and Discovery Article #91015©1992 AAPG International Conference, Sydney, N.S.W., Australia, August 2-5, 1992 (2009)