THE SEDIMENTATION AND SEDIMENTARY HISTORY OF THE ABERYSTWYTH GRITS (UPPER LLANDOVERIAN)

Abstract

The greywacke beds were deposited from turbidity currents in a region within the mud belt. These currents came from an area lying to the south-west and south-south-west, its configuration varying with time. Variation in type of deposit is correlated with distance from land, and evidence of successive rejuvenations of the source area is presented. Sedimentary injection dykes occurring in the south are held to prove that some currents were set in motion by earthquakes, but slumping from the edge of the sedimentary terrace caused by loading, together with the action of storms (in the south), probably also assisted in the transfer of material to deeper water.