Late Pliocene to Holocene planktonic foraminifers of the Guaymas Basin, Gulf of California, Sites 477 through 481.

Abstract

Eight holes were drilled at five sites in the Guaymas Basin during DSDP Leg 64. Holes 477, 477A, 477B, 481, and 481A were drilled in the two spreading rifts in the central part of the basin, and Hole 478 in the flat basin floor. The sediment dates from the Pleistocene to Holocene epoch. Sites 479 and 481 are on the continental slope within the depths of the present oxygen-minimum zone. The six basal cores from Hole 479 are from the late Pliocene epoch, and an unconformity seems to occur between the upper Pliocene and the overlying Pleistocene sequence. Hole 480 was drilled with a hydraulic piston corer and contains an upper Pleistocene to Holocene sequence of well-laminated diatomaceous mud.-Authors