Coal samples in the form of randomly oriented aggregates were obtained from the Pennsylvania State University Coal Bank for the purpose of thermal conductivity measurements. Samples represented 55 locations from throughout the United States and included 6 lignites, 10 subbituminous coals, 36 bituminous coals, and 3 anthracite samples. Matrix thermal conductivities measured at 22°C in the laboratory ranged from 0.22 to 0.55 W/m°K, with an arithmetic mean of 0.33 W/m°K and a standard deviation of 0.07 W/m°K. The thermal conductivity of lignites, subbituminous, and bituminous coals is controlled by composition and can be predicted by a three‐component (moisture, ash, and carbon + volatiles) geometric mean model with an rms residual of 6.1%. The thermal conductivity of bituminous and anthracite samples was found to be positively correlated with matrix density. With the exception of three anthracite samples, rank was not correlated with thermal conductivity, nor was the ratio of carbon to volatiles. The relatively high thermal conductivity of three anthracite samples (mean of 0.49 W/m°K) may have been related to graphitization.

A study using multiple techniques provided insight into tectonic influences on ground water systems; the results can help to understand ground water systems in the tectonically active western United States and other parts of the world. Ground water in the San Bernardino Valley (Arizona, United States and Sonora, Mexico) is the main source of water for domestic use, cattle ranching (the primary industry), and the preservation of threatened and endangered species. To improve the understanding of ground water occurrence, movement, and sustainability, an investigation was conducted using a number of complementary methods, including major ion geochemistry, isotope hydrology, analysis of gases dissolved in ground water, aquifer testing, geophysics, and an examination of surface and subsurface geology. By combining information from multiple lines of investigation, a more complete picture of the basin hydrogeology was assembled than would have been possible using fewer methods. The results show that the hydrogeology of the San Bernardino Valley is markedly different than that of its four neighboring basins in the United States. The differences include water quality, chemical evolution, storage, and residence time. The differences result from the locally unique geology of the San Bernardino Valley, which is due to the presence of a magmatically active accommodation zone (a zone separating two regions of normal faults with opposite dips). The geological differences and the resultant hydrological differences between the San Bernardino Valley and its neighboring basins may serve as a model for the distinctive nature of chemical evolution of ground water in other basins with locally distinct tectonic histories.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractHorizon attributes, i.e., attributes that numerically describe geometric characteristics of interpreted horizons from conventional (i.e., p-wave) 3-D seismic volumes, hold considerable potential for identifying fracture-swarm sweet spots in low permeability reservoirs.

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