Refraction studies between Icy Bay and Kayak Island, eastern Gulf of Alaska

Abstract

Results of five seismic refraction lines shot by the U.S. Geological Survey in the Gulf of Alaska between Icy Bay and Kayak Island indicate the following: 1) The continental shelf is underlain by as much as 11 km of sedimentary rock of probable Tertiary age with refraction velocities ranging from 1.2 -5.5 km/sec; 2) a section approximately 5 km thick with velocities of 4.1 -5.5 km/sec that could represent the early Tertiary Orca Group is present in the western part of the study area but not in the eastern part; and 3) consistent basement velocities of approximately 7.0 km/sec could indicate oceanic crust underlying the continental margin.