Glacially-Influenced Sediment Drifts in the Rockall Trough

Abstract

Sediment drifts are a major depositional product of bottom-current activity in deep-water settings, particularly on slopes and basin plains within, and adjacent to, continental margins. They commonly form positive features on seismic reflection profiles. Bottom-current reworking of sediment, which may be derived from turbidity currents or pelagic/hemipelagic processes, is the major factor controlling the development of sediment drifts. In the vicinity of glaciated margins they are also likely to receive an input of coarse-grained material, including gravel-sized dropstones, derived through ice-rafting processes. Thus, despite subsequent bottom-current reworking, a distinct glacimarine signature will be retained within the sediments. Such deposits form an important component of the late Cenozoic sediment drifts in the northeast Rockall Trough (Fig. 1), where a record of distal glacimarine sedimentation, since the late Pliocene, is preserved [Stoker et al., 1993].