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T. H. Kiilsgaard

Publications and source records attributed to T. H. Kiilsgaard.

12 recordsLinked to original sources
USGS2001

Soil gas studies along the Trans-Challis fault system near Idaho City, Boise County, Idaho

Soil gases were sampled along several traverses that cross the Trans-Challis fault system in central Idaho. Anomalous carbon dioxide, hydrogen, oxygen, hydrocarbon, and sulfur gas concentrations coincide with faults and known mineralized areas. Anomalies in areas not known to be mineralized may reflect undiscovered mineral deposits or concealed faults. Soil gases may be a useful exploration guide for mineral deposits in this terrane.

Idaho↗
USGS1983

Landsat analysis of the Yangjiatan tungsten district, Hunan Province, People's Republic of China

The Yangjiatan tungsten district at latitude 27??28??? N. and longitude 111??54???E. is located about 140 km southwest of the city of Changsha and 35 km northeast of the town of Shaoyang, southeast Hunan Province, People's Republic of China. The deposits, consisting largely of scheelite in veins (Wang, 1975), are contained in highly folded and faulted sedimentary rocks of Paleozoic, Mesozoic, and Cenozoic age intruded by granitic plutons that are circular in plan view. The major faults and folds trend in a northeasterly direction; whereas, the plutons are clustered in a more easterly trending band across the Landsat image. Landsat image E-2338-02202, acquired December 26, 1975, is number 470 in the "Landsat Image Atlas of the People's Republic of China" printed by the Publishing House of Geology in 1979. A computer-compatible tape of the image was analyzed and used as a demonstration project under a United Nations technical assistance program. Supervised classification of soils, rocks, and vegetation; band ratioing to detect limonite alteration; and edge enhancement were all conducted to demonstrate the flexibility and capability of interactive computer systems. Field evaluation of the results of this work will be conducted by colleagues of the Remote Sensing Center for Geology, Ministry of Geology, in China. ?? 1983.

Advances in Space Research↗
USGS1975

Exploration for nickel at Jabal Jedair, southeast of Ranyah, Kingdom of Saudi Arabia

Anomalous nickel values were found in oxidized ultramafic rock at Jabal Jedair (lat 21°04'N.; long 43'29'E.) by Louis Gonzalez in 1969. Information gained from shallow trenching and pitting suggested that nickel-bearing sulfides might exist at depth. Geophysical surveys, including magnetic, gravity, and self-potential, were conducted in 1974. A linear magnetic anomaly indicated a conductor (sulfides?) was present. Two holes were drilled in August and September to test subsurface rocks below a gossan containing anomalous nickel, the trend of which is marked by a linear magnetic anomaly. The drill holes penetrated oxidized rock to a vertical depth of about 35 m. Rock penetrated by the holes is principally gabbro containing zones of serpentinite. Both holes also penetrated a section of massive black serpentinite, 25-37-m thick, containing abundant pyrrhotite. The deepest hole, 176 m inclined, reached a vertical depth of 135 m and bottomed in gabbro containing thin dikes of granodiorite. Analyses of core from the pyrrhotiferous zone indicate an average nickel content of 2468 ppm (0.24 percent), which is not high enough in grade to be classed as ore. Analyses of gossanabove the pyrrhotiferous rock averaged 261 ppm nickel, which indicated that nickel was leached from the sulfide zone duringoxidation. About 8.5 million metric tons of pyrrhotized rock are indicated from the drill holes, but this material is too low in nickel content to be mineable. No further exploration of the deposit is warranted.

Jabal Jedair↗