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The effectiveness of the electrical resistivity method has been studied using various configurations with different spacings over the Southern Boundary Fault in the northwestern part, and across a dolerite dyke named "Salma dyke" in the central part, of the Raniganj Coalfield, India. It has been observed that the delineation of the fault and the dyke was made possible under differential tropical weathering conditions. Geoelectric sections across the fault and the dyke have been prepared on the basis of Schlumberger sounding results. In profiling, Wenner, two-electrode, half-Schlumberger and part of Al-Chalabi's configurations were applied over the Southern Boundary Fault. Across the dyke, alpha-, beta-, and gamma-Wenner, Schlumberger, half-Schlumberger and two-electrode configurations were employed. Azimuthal two-electrode sounding was also studied over the fault.The interpretation of the results of apparent resistivity profiles across the Southern Boundary Fault suggests that the Wenner and two-electrode configurations possess certain diagnostic features which help in mapping a single lithological contact, provided sufficient resistivity contrast exists. Although Schlumberger configuration seems to be quite suitable, other configurations may also be usefully employed over the dyke.

Crystallography of alpha-quartz is discussed with special referenoe to the existing ambiguities regarding handedness of its enantiomorphic forms and a mnemonic has been suggested. Previous x-ray diffraction topographic ,studies of synthetic quartz are critically reviewed and analysed to understand the origin, nature and location of dislocations. It is suggested that dislocations associated with cell boundaries, characteristic of the Z-zone grown portions of synthetic quartz, are pure a-type edge dislocations but possibly with an alternating non-conservative climb component associated with the predominating glide component.

Abstract— The Devri‐Khera meteorite fell on 1994 October 30 in the Jhalwar district of Rajasthan, northwestern India. The texture, mineralogy and mineral and bulk compositions show that Devri‐Khera is an L6 chondrite of shock facies S4.

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