Mineral Distribution Within the Sediments of Pearl Harbor.

摘要

Some of the metal concentrations reported for areas in Pearl Harbor,Hawaii may be the result of natural processes, i.e.,chromium and nickel in relation to the basaltic mineral suite,and iron,zinc,lead,and copper to the distribution of anaerobic bottom conditions. Montmorillonite is found in greatest abundance in the southeast Loch area near the bentonitic Salt Lake tuff;its general distribution throughout the Harbor is governed by proximity to highly montmorillonitic soils and tuffs and the degree of vertical mixing within the stratified water column. The distribution of authigenic pyrite in the Harbor is related to the depth to the anaerobic layer and to the distribution of organic matter. Estuarine stratification is pronounced in West and Middle Lochs,and the stability of the water column combined with the high influx of organic matter renders the bottom layer anoxic. In West Loch the production of H2S in the sediments may restrict the habitat of foraminifera to the shallow (probably the upper 5 m) periphery of the Loch;the character of the foraminiferal population fluctuates greatly with the volume of fresh water influx and the effects of prevailing winds on the brackish layer. Coral fragments and clayey carbonaceous sediments indicate dredge spoils.