HEAVY MINERALS OF THE U. S. SOUTH ATLANTIC CONTINENTAL SHELF AND SLOPE

摘要

Heavy minerals from the U. S. South Atlantic continental shelf and upper slope have been studied. In comparison with other areas such as the Gulf of Mexico shelf, both qualitative and quantitative variation in heavy minerals is subdued mainly due to similar provenance areas for most of the major rivers. Two heavy-mineral provinces can be defined, based primarily on the epidote content. A close areal relationship between capes and certain heavy-mineral anomalies was noted indicating that processes forming the capes and their associated seaward-extending shoals are important factors in sediment distribution. Roundness observations were made on garnet, kyanite, staurolite, and tourmaline grains. Garnet and kyanite exhibit strong roundness anomalies, both minerals being better rounded in the northern portions of the study area. Roundness-distribution histograms indicate dual-sediment sources in some instances.