Science survey 1: edited by A. W. Haslett and John St. John. 359 pages, plates, diagrams, [formula omitted] New York, The Macmillan Co., 1960. Price, $5.75

Abstract

Important processes determining the marine geology adjacent to the Hawaiian Islands include volcanism, isostatic adjustment, and sedimentation. The crust under the Hawaiian Islands has subsided 2–6 km under the large shield volcanoes, and the adjacent sea floor has been downwarped accordingly. Although the crust and upper mantle are depressed in the Hawaiian Deep, they apparently are sufficiently elastic to be broadly upwarped in the Hawaiian Arch, outside the Deep.The sediment filling the moat near the islands is a mixture of detrital and authigenic silicates and organic carbonates. It has slumped down the submarine slopes and through submarine canyons. The sediment loses its carbonate content on the deep sea floor. Its authigenic illite, kaolinite, and montmorillonite, as well as its detrital and pyroclastic feldspar, pyroxene, magnetite, and grains of volcanic rock are diluted by pelagic quartz, illite, Radiolaria, and lesser components. Sedimentological studies are interpreted within the framework of the regional tectonic and geomorphic setting.The sea floor about 150 km north of the island of Maui has been proposed as the site for the Mohole project. The site is covered with brown clay that mantles a surface of low relief south of the crest of the Hawaiian Arch. A small fracture north of the site and some low seamounts about 40 km distant are the only obvious features nearer than 100 km to the site. The area is in the western part of the Baja California Seamount Province where there is no indication of gross abnormality of structure, topography, sediment, or history. Therefore, the proposed drilling site north of Maui appears to be in an area that represents typical oceanic crust.