Aleutian Deep-sea Channel on the Aleutian Abyssal Plain

Abstract

THE Aleutian abyssal plain is a vast turbidite deposit south of the Aleutian trench (Fig. 1). Hurley noted¹ that the plain had been cut off from turbidity currents as a result of the downbowing of the trench which had interrupted the turbidity current process along the bottom. In support of this thesis, seismic reflexion evidence² indicated an unusually thick layer of pelagic sediments overlying the turbidite layers on the Aleutian plain, and, using pelagic sedimentation rates, he placed the cessation of turbidity current activity in the early to middle Tertiary. The discovery of the Seamap channel³, which is beheaded by the Aleutian trench, provided striking further evidence of the fossil nature of the Aleutian plain.