Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

K. Ayyasamy ¹, V., Ganesan ², C. V. L. Narasimham ³

Affiliations
1 298/2RT, Vijayanagar Colony, Hyderabad 500 457, IN
2 Chandra Vihar, Mukram Jahi Road, Hyderabad 500 001, IN
3 2-11-252/11, Begumpet, Hyderabad 500 016, IN

Abstract

The paper records the find of a new species of the genus Physa, occurring in the infra-trappean beds of Andhra Pradesh, India. Discussions on the distribution, phylogenetic significance and the stratigraphic importance of this new find are presented.

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C. Ramachandran ¹, C. V. L. Narasimham ²

Affiliations
1 Geological Survey of India, AMSE Wing, Prestige Complex, 2nd Church Street. Bangalore 560001, IN
2 Geological Survey of India, Training Institute, 2.11.252/11, Jabbar Building, Begumpett Hyderabad 500016, IN

Abstract

The compressional wave velocity, compressive strength, tensile strength, permeability and density are measured for some coal-bearing rocks of Eastern India. The ranges of compressional wave velocities for the different rock types are presented. It is observed that the compressional wave velocity in sandstones increases linearly with increase of density, compressive strength, tensile strength and Young's modulus. The absorption coefficient of compressional waves in sandstones decreased linearly with increase of Young's modulus. The permeability, determined in a few sandstone samples, increased with porosity.

Empirical relations obtained by least squares technique are also presented, relating to the variation of compressional wave velocity with density, Young's modulus and the strength of sandstones. The results would find application in coal exploration and extraction.

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