Geology, drilling, and some hydrologic aspects of seismic hazards program core holes, Los Alamos National Laboratory, New Mexico
- Los Alamos National Lab., NM (United States)
- Woodward-Clyde Consultants, Oakland, CA (United States)
As part of the Los Alamos National Laboratory`s Seismic Hazards Investigations Program, we have cored four holes, as follows: SHB-I at TA-55 to 700 feet; SHB-2 at TA-3 to 200 feet; SHB-3 at TA-16 to 860 feet; and, SHB-4 at TA-18 to 200 feet. In that the near-surface seismic velocity structure of the holes is the subject of other reports, we describe here the lithologies, general aspects of drilling, and some hydrologic implications of the core holes. All four holes penetrated variably welded Tshirege Member of the Bandelier Tuff. Beneath two deeper holes encountered thick sequences of epiclastic sands and gravels, with minor interbeds of Cerro Toledo Rhyolite, on top of the dominantly nonwelded Otowi Member of the Bandelier Tuff. Beneath the Otowi was basalt at TA-55 and Puye Formation sands and gravels at TA-16. Two of the core holes (SHB-3 at TA-16 and SHB-4 at TA-18) appear to have encountered groundwater. The holes were all continuously cored with conventional wireline diamond coring techniques. Maintaining high percentage core recovery in nonwelded tuff and loose formations with air as the circulating fluid proved impossible. Light muds, however, improved recovery in these zones considerably. A variety of bits were tested, but none yielded consistent results in the alternating hard and soft rock conditions found beneath the Laboratory.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 138661
- Report Number(s):
- LA-12460-MS; ON: DE93011473
- Resource Relation:
- Other Information: PBD: Jan 1993
- Country of Publication:
- United States
- Language:
- English
Similar Records
Stratigraphy and Geologic Structure at the Chemical and Metallurgy (CMR) Building, Technical Area 3, Los Alamos National Laboratory
High-precision geologic mapping to evaluate the potential for seismic surface rupture at TA-55, Los Alamos National Laboratory