Heavy minerals constitute a natural resource which, under proper conditions, could have potential economic significance. The purpose of this report is to describe the heavy-mineral distribution in sea-floor sediments On the South Texas Outer Continental Shelf (OCS) within the northwestern Gulf of Mexico. The South Texas OCS encompasses approximately 24,500 sq km extending southward from Matagorda Bay to the U.S.-Mexico border (fig. 1). In a shoreward direction, the OCS extends from the 180-m isobath to the Federal-State water boundary (16.6 km offshore); however, the mineral distribution patterns presented in these maps have been extrapolated slightly shoreward of the l5-m isobath. This work was part of a regional environmental studies program in the South Texas OCS that was conducted in conjunction with the offshore petroleum-lease sales, under the auspices of the U.S. Bureau of Land Management. Some previous work on heavy minerals within the OCS had been done by van Andel and Poole (1960) and van Andel (1960); the fOrIner work was based on relatively few OCS samples and was part of a broader regional study of the northern Gulf of Mexico.
