From purpose of study: The Vallecito Conglomerate of the Needle Mountains area in southwestern Colorado was studied to evaluate the uranium potential of the unit and to test the applicability of the uraniferous Precambrian pebble-conglomerate exploration model in this area. The main thrust of this project is the Vallecito Conglomerate, but the Uncompahgre Formation, which is also in the Needle Mountains area has basal conglomerate that was investigated in a reconnaissance mode. Five specific objectives have been formulated to meet the overall purpose of this project, and these include: a) Determine the uranium distribution in the Vallecito Conglomerate and the basal conglomerate of the Uncompahgre Formation. b) Evaluate the uranium resources of the area to the degree possible utilizing available information and personal field investigations. c) Test the validity of application of the Precambrian quartz-pebble conglomerate model to this area. d) Recommend detailed studies and delineate drilling sites in the area to further evaluate the uranium resources if warranted. e) Recommend additional geologic, geophysical and geochemical studies which would bear directly on evaluation of uranium resources of the Precambrian pebble conglomerates in the Needle Mountains area.

From introduction: This report presents uranium and other elemental data resulting from the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Shiprock National Topographic Map Series (NTMS) quadrangle, New Mexico/Arizona, by the Los Alamos Scientific Laboratory (LASL).

Results of the Lakeview detailed geochemical survey are reported. Field and laboratory data are reported for 231 groundwater, 881 stream sediment, and 303 stream water samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the area is provided and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed.