Initial Reports of the Deep Sea Drilling Project - Volume 62

This volume covers Leg 62 of the cruises of the Drilling Vessel Glomar Challenger. As part of a program developed by a working group ("Evolution of Planktonic Communities") set up by the JOIDES Ocean Paleoenvironment Panel in 1975, we examined late Mesozoic and Cenozoic paleoenvironments in the central North Pacific Ocean during DSDP Leg 62. The drilling program was specifically designed to contribute to the understanding of the history of pelagic sedimentation and of the evolution of planktonic communities in the North Pacific Ocean. The four sites drilled during Leg 62 were needed to establish better regional coverage. Although paleoenvironments were to be stressed on Leg 62, studies of igneous rocks from acoustic basement were planned, to determine ages, petrogenesis, alteration effects, rock magnetism, and Paleomagnetism of old parts of the Pacific crust. These studies were emphasized in order to establish the early history of oceanic plateaus and whether they are the result of mid-ocean-ridge or intraplate volcanism. Glomar Challenger departed Majuro, Marshall Islands, on 29 July 1978, and arrived in Honolulu, Hawaii, on 7 September. We drilled five holes at four sites. One site (463) was drilled on the western part of the Mid-Pacific Mountains, and three sites (464, 465, and 466) were drilled on the Hess Rise.