The Quarterly Journal of the Geological Mining and Metallurgical Society of India. June 1953

S. RAY CONTENTS Studies on the Soils of Dann of Cutch—By N. Sen and K. V. S. Satyanarayana 51 The Correlation of the Gondwanas (?) of the Guntur District by Sedimentary Petrographic Methods—By M. Poornachandra Rao 61 Some aspects of the Petrology of the Rajmahal Traps—By Biswanath Mitra 75 Variations in level of the base of the Deccan Trap in Hyderabad State—By S. R. Sarma... [...] Features like increase of heavy percentage up the profile as also the increase of the coarser grades of the traction load indicate a shallowing of the Rann while similar increase of the finer grades of the suspension load probably points to a maturing of the soils of the surrounding plain. [...] The predominance of mica in 7oll-9oli layer of Nanda profile brings out a unique difference of this horizon in relation to the mineral assemblage of the rest of the profile as well as of the other two profiles. [...] All these together with a consideration of the variation in the mineral assemblage as noted earlier gives a general picture of shallowing up of the Rann with a maturity of the soils'of the mainland and the Rann as well. [...] LABORATORY INVESTIGATION The methods of work consist in sampling ' of the bulk material for laboratory analysis the technique of segregating heavy minerals from the sediment the sampling of the obtained residue the mounting of the sampled heavy grains for microscopic examination and finally the study of the optical characters of the heavy minerals and counting with the assistance of a mechanica