Seismic evidence for Early Tertlary bottom-current controlled deposition in the Charlie Gibbs Fracture Zone

Abstract

Buried, mounded and acoustically transparent sediment bodies banked up against a basement ridge at the eastern end of the Charlie Gibbs Fracture Zone are interpreted as a type of contourite drift. As they are probably of Eocene—?Palaeocene age, their origin has implications for the little-known deep circulation pattern in the NE Atlantic during this period. Possible sources for the bottom currents responsible for these drifts include Labrador Sea Water, Norwegian Sea Overflow Water, Antarctic Bottom Water or a Gulf Stream deep gyre system. The preferred source is an early development of Antarctic Bottom Water or an arm of a Gulf Stream Gyre flowing eastwards through the fracture zone.