Modern Sand-Rich and Mud-Rich Siliciclastic Aprons: Alternative Base-of-Slope Turbidite Systems to Submarine Fans

Abstract

Base-of-slope aprons that lack significant channel development and are fed by multiple sediment sources (i.e., numerous slope failures or debris chutes) represent an alternative facies organization to submarine fans that possess channels and are fed by canyon point sources of allochthonous sediment. Two styles of base-of-slope apron deposition are evident: (1) sand-rich aprons with rhythmic, gradational sand and gravel sheets that evolve to basin-plain turbidites as exemplified by Crater Lake aprons, and (2) mud-rich aprons composed of chaotic sediment flow lobes without gradation as exemplified by Ebro margin aprons.