Southern California Outer Continental Shelf "No-Data" Map

This dataset represents the areas the Southern California continental shelf for which no data was collected by PS Associates of Cardiff, California (1987) to determine substreate type (exposed rock or sediment). The dataset is derived from a map series of seven adjacent but descrete maps illustrating the absence of information on seafloor sediment and rock. The purpose of this project was to create digital, GIS format versions of the Southern California continental shelf seafloor substrate maps originally produced by PS Associates of Cardiff, California for the Minerals Management Service in Reston, Verginia. The original data was presented in hard copy format and depicted areas of "rock outcrop, hard-ground, or less than 1 meter of sediment overlaying." In areas where no rock was identified, we designated this as "sediment". Note that this is liberal interpretation of the original map data. A more conservative and accurate interpretation involved using "no data" maps which indicated the areas in which no information on substrate type was gathered. Please see the "no_data" dataset that is part of this series. Original map title: Isopach map of the post-Wisconsin sediment thickness data sources. California Outer Continental Shelf Archeaological Resource Study from Morro Bay to the Mexican Border. Prepared by P.S. Associates, Contract number 14-12-0001-30272, May 1, 1987. Map scale was 1:125,000. Used maps 1B, 2B, 3B, 4B, 5B.