WARTES, MARWAN A., University of Wisconsin-Madison, Dept. of Geology and Geophysics, Madison, WI

ABSTRACT: An Integrated Study of Large Submarine Channels in the Yakataga Formation, Gulf of Alaska: Complete Outcrop Exposures of an Important Reservoir Analogue

Channelized reservoirs are a highly productive setting in many petroleum systems. However, targeted sandstone bodies are often at sub-seismic scales and exploration requires the use of a meaningful depositional model. Unfortunately, very few regions of the world exhibit complete exposures of submarine channels in the rock record.

This study will add to our comparative database by examining a unique series of very large submarine channels preserved in the Neogene Yakataga Formation along the Gulf of Alaska. This unit is spectacularly exposed along the east-west strike of the coastal ranges. At least 13 separate megachannels have been noted by reconnaissance studies; some of these features exceed 3 km in cross sectional width and are up to 400 m deep. Most of the deposits represent sediment gravity flows indicating a wide spectrum of depositional processes ranging from debris flow events to higher energy turbidites.

The main field component of this study will be standard sedimentologic and stratigraphic description of the facies present. A comprehensive sampling strategy is planned in which sandstones representing various elements of the megachannel fill will be analyzed for porosity and permeability. Additional work will take advantage of the unparalleled seismic scale exposures by compiling photomosaics aimed at documenting larger scale stratigraphic geometries and the distribution of facies components. It is anticipated that this combination of observational scales will aid in the generation of an integrated facies model of value to reservoir geologists and the sedimentologic community in general.

AAPG Search and Discovery Article #90909©2000 AAPG Foundation Grants-in-Aid