Initial Reports of the Deep Sea Drilling Project - Volume 32
Creators: name: Larson, R.L.
name: Moberly, R.
name: The Leg 32 Science Party
Publisher: name: U.S. Government Printing Office
Year: 1975
Subjects: Deep Sea Drilling Project
Glomar Challenger
DSDP
Leg 32
Site 303
Site 304
Site 305
Site 306
Site 307
Site 308
Site 309
Site 310
Site 311
Site 312
Site 313
Western Pacific Ocean
Hawaiian Ridge
Shatsky Rise
Hess Rise
Köko Guyot
Emperor Seamount Chain
Japanese Magnetic Lineations
Hawaiian Magnetic Lineations
Mid-Pacific Mountains

description: This volume covers Leg 32 of the cruises of the Drilling Vessel Glomar Challenger. The northwestern Pacific Ocean is the largest expanse of old oceanic lithosphere, and so the principal theme of Leg 32 set by the Pacific Advisory Panel was the late Mesozoic history of the Pacific Ocean. The main scientific goals originally set for the leg were to: 1) Determine the development of the very deep sea floor of the western Pacific, including the nature of its basement rocks and the age, lithology, and fossil content of the sedimentary rocks overlying acoustic basement. Patterns of linear magnetic anomalies that do not match the sequence of well-dated latest Cretaceous to present-day reversals are present east of Japan, west of the Hawaiian Ridge, near the Phoenix Islands, and bordering the North Atlantic. A principal aim of Leg 32 was to test correlations of these old anomalies by drilling specific sites on the Japanese and Hawaiian sets. 2) Establish standard mid-Mesozoic to Recent paleontological-biostratigraphic reference sections for the (present-day) northwest Pacific. Shatsky Rise and Hess Rise are the northern-most of the few broad and irregularly shaped areas of the sea floor that are sufficiently shallow so calcareous fossils are likely to be preserved and yet are isolated from dilution by terrigenous components. 3) Determine the paleolatitude for a specific period of volcanicity on Köko Guyot of the Emperor Seamount Chain, which, when compared with the paleolatitude of Midway Islands and the present-day latitude of the active volcanoes on Hawaii, can test a version of the hot-spot theory—that a source of magma generation has remained fixed in the earth's mesosphere while the Pacific lithospheric plate has moved across it, with resultant volcanoes forming first the Emperor Seamounts and, after a change in direction of plate motion, the Hawaiian Ridge. Several other geological and operational goals were to include: tracing the paleoequator in the stratigraphic records at the deep-water and rise sites; gathering cores for isotope analysis for paleooceanography studies; determining effects of diagenesis in carbonate and zeolite facies; geochemical and geophysical studying of mid-Mesozoic basalts; first DSDP operational testing of a heave compensation system and a system for taking oriented cores; drilling in very deep water on several sites; and using a transducer on the drill string. D/V Glomar Challenger departed Hakodate, Japan, on 16 August 1973 and terminated the voyage in Honolulu, Hawaii, on 10 October 1973. During this leg, Glomar Challenger cruised 4712 nautical miles, drilled 12 holes while investigating 11 sites, and cored 2210.5 meters of material.