From 1995 sites in the San Juan Mountains area, 1706 water and 1982 sediment samples were collected during June-July 1976 and analyzed for uranium. The area includes the southern third of the Colorado mineral belt which has yielded rich ores of gold, silver, copper, lead, zinc, and molybdenum. The broadly domed mountains are capped by 2500 m of Tertiary volcanics, deeply eroded to expose a Precambrian crystalline core. Adjacent plateaus underlain by Mesozoic sedimentary rocks were included in the reconnaissance. Average value of uranium in water samples from mountains was less than 0.5 parts per billion, from plateaus was 1-2 parts per billion, from Mancos shale areas exceeded 2 parts per billion. Anomalous sediment samples, 40 ppm uranium, came from near Storm King Mountain and upper Vallecito Creek. Other anomalous areas, including the Lake City mining district, were well defined by 4-30 parts per million uranium in sediment and 3-30 parts per billion uranium in water. Anomalous areas not previously reported indicate favorable areas for future exploration.

This is a set of 62 plates that accompany a report on uranium favorability in rocks of the south Texas coastal plain.

From addendum: Two types of analyses for uranium in the stream-sediment samples are presented. One split of the stream-sediment samples was sent to Resource Associates of Alaska's laboratory, where they were analyzed for U by the fluormetric method after acid extraction. This is the method employed for U by most laboratories. The completeness of uranium extraction unavoidably varies with the particular type of uranium-bearing minerals present and possibly with the amount of iron, manganese, and carbonaceous material present, which can interfere with the extraction. Analyses by the method are shown in the text and appendix columns with the designation "RAA."

From objectives: This report demonstrates the concept of hydrogeochemical sampling to be used in the 12-state region for which UCC-ND has the responsibility if surveying as part of the NURE. The results of a geochemical survey at two sample spacings in the Crystal City Quadrangle in south Texas are presented.

From purpose and scope: The objective of this study was to delineate areas of maximum uranium favorability in Tertiary sediments that underlie part of the South Texas Coastal Plain.

Data collected as part of a uranium geochemical survey in the Crystal City and Beeville Quadrangles in Texas including laboratory data stream sediments and water, well water, and botanical samples for phase 1 (pp. 1-8); for phase 2 including the same with lake samples (pp 9-36); well water samples only for phase G (p. 37); and field data for all phases (pp. 38-374).

Supplementary data containing geologic maps stratigraphic cross-sections to accompany a report on uranium favorability in the South Texas Coastal Plain.