Geologic and Well-Construction Data for the H-10 Borehole Complex Near the Proposed Waste Isolation Pilot Plant Site, Southeastern New Mexico

摘要

The H-10 borehole complex, a group of three closely spaced boreholes, is located 4 miles southeast of the proposed Waste Isolation Pilot Plant site in west-central Lea County, New Mexico. The holes were drilled during August and October 1979 to obtain geologic and hydrologic data to better define the regional ground-water-flow system. The geologic data presented in this report are part of a site-characterization study for the possible storage of defense-associated radioactive wastes within salt beds of the Salado Formation of Permian age. The geologic data include detailed descriptions of cores, cuttings, and geophysical logs. Each borehole was designed to penetrate a distinct water-bearing zone: H-10a (total depth 1318 feet) was completed just below the Magenta Dolomite Member of the Rustler Formation of Permian age; H-10b (total depth 1398 feet) was completed just below the Culebra Dolomite Member of the Rustler Formation; and H-10c (total depth 1538 feet) was completed below the Rustler Formation-Salado Formation contact. The geologic units penetrated in borehole H-10c are surficial alluvium and eolian sand of Holocene age (0 to 5 feet); the Mescalero caliche (5 to 9 feet) and the Gatuna Formation (9 to 90 feet) of Pleistocene age: formations in the Dockum Group (Chinle Formation, 90 to 482 feet and Santa Rosa Sandstone, 482 to 658 feet) of Late Triassic age; and the Dewey Lake Red Beds (658 to 1204 feet), the Rustler Formation (1204 to 1501 feet), and part of the Salado Formation (1501 to 1538 feet), all of Permian age. The sections of the Rustler and Salado Formations penetrated by borehole H-10c are complete and contain little or no evidence of dissolution of halite and associated rocks, indicating that the eastward-moving dissolution within the Rustler or on top of the Salado, found west of the Waste Isolation Pilot Plant site, has not reached the H-10 site. (ERA citation 10:022464)