Sediment Distribution in the Southern Oceans around Antarctica

Abstract

ABSTRACT The distribution of sediment types is shown on a map drawn on a polar projection, which covers the southern oceans northward to 52° S. Latitude on two margins and to 19° S. Latitude in the corners. The type of bottom sediment at over 500 stations, as reported in the literature prior to 1947, has been plotted. To this information have been added data obtained by the writer and others engaged in the U. S. Navy Antarctic Expedition of 1946-47. Sediment distribution boundaries are shown, based in part on those previously published on other projections, and adjusted to conform to the latest available information. In general, Antarctica is bordered by a deposit of glacial marine sediment which roughly coincides with the area of pack ice; the next zone to the north contains diatom ooze which extends northward to the position of the Antarctic convergence or to the line where the Antarctic surface water turns under normal open ocean water. North of the convergence, in the open ocean, the bottom sediment is red clay in the deeper water and a calcareous ooze in the shallower water. Near shores, terrigenous sediments of various kinds are found. There are many local variations to this pattern. The map is published in order to present the known data on a polar projection, and to indicate the need for further information from vast areas of ocean bottom in these regions which have never been sampled. Stratification of the sediments is discussed, and the need for study of core samples of the bottom is emphasized.