Interpretation of geophysical well-log measurements in drill holes UE25a-4, -5, -6, and -7, Yucca Mountain, Nevada Test Site

Technical Report · Thu Dec 31 04:00:00 EST 1981

OSTI ID:59632

Daniels, J J; Scott, J H; Hagstrum, J T

Exploratory holes UE25a-4, UE25a-5, UE25a-6, and UE25a-7 were drilled at the Nevada Test Site (NTS) to determine the suitability of pyroclastic deposits as storage sites for radioactive waste. Studies have been conducted to investigate the stratigraphy, structure, mineralogy, petrology, and physical properties of the tuff units encountered in the drill hole. Ash-flow and bedded tuff sequences at NTS comprise complex lithologies of variously welded tuffs with superimposed crystallization and altered zones. Resistivity, density, neutron, gamma-ray, induced-polarization, and magnetic-susceptibility geophysical well-log measurements were made to determine the physical properties of these units. The interpretation of the well-log measurements was facilitated by using a computer program designed to interpret well logs. The broad features of the welded tuff units are readily distinguished by the geophysical well-log measurements. Some mineralogic features in the drill holes can be identified on the gamma ray, induced polarization, and magnetic susceptibility well logs.

• Research Organization: Geological Survey, Reston, VA (United States)
• DOE Contract Number: AI08-78ET44802
• OSTI ID: 59632
• Report Number(s): USGS-OFR--81-389
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
BOREHOLES
COMPUTER CALCULATIONS
INDUCED POLARIZATION LOGGING
MINERALOGY
NEUTRON-GAMMA LOGGING
NEVADA TEST SITE
PETROLOGY
PHYSICAL PROPERTIES
RADIOACTIVE WASTE STORAGE
RESISTIVITY LOGGING
SITE SELECTION
STRATIGRAPHY
TUFF
WELL LOGGING
Yucca Mountain Project