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

O. P. Goel ¹, G. C. Kandpal ¹, S. S. Garhia ¹

Affiliations
1 Department of Geology, Kumaun University, Nainital 263 002, IN

Abstract

The medium grade metasedimentary rocks of Precambrian age around Paharpani, occurring in association with magmatites, gneisses, granites and/or granodiorites constitute a part of the Almora Group. The rocks show complex structures resulting from multipe deformations. Mesoscopic and macroscopic struc1ures indicate that the intense first deformation produced tight to isoclinal reclined folds (F₁), leading to thrusting of the Almora Group of rocks over the low grade metasedimentary rocks of the Ramgarh Group along the South Almora Thrust. The effect of less severe deformation on these F₁ folds was the formation of warps, crenulations and upright to inclined folds (F₂), which show a variation in trend from NW/WNW to SE/ESE and plunge from 12° to 40°, The last phase of deformation produced NNE-ENE trending asymmetrical, open folds (F₃) and crenulations. Superposition of F₂ folds has resulted in type 1 interference patterns of Ramsay.

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O. P. Goel ¹, S. S. Garhia ¹, J. S. Mehta ¹, G. C. Kandpal ¹

Affiliations
1 Department of Geology, Kumaun University, Nainital 263002, IN

Abstract

A preliminary study and interpretation of LANDSAT-I imagery, covering a large area of Kumaun-Garhwal Himalaya. lying between 79° - 80°30' East longitude and 29°0' - 30°30' North latitude, reveals the presence of four dominant directions of lineaments trending NS, NE-SW, NW/WN-SE/ESE and E-W. The lineament fabric of the region represents axial directions of major folds, regional strike trends of thrusts and of transverse or strike-slip faults. The study is supplemented by detailed structural analysis of mesoscopic folds, planar and linear features present in rocks of three sections of the Kumaun Himalaya and it is suggested that the deformation in rocks of the region was the result of both compressional, tensional, and vertical uplift.

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S. S. Garhia ¹

Affiliations
1 Geological Survey of India (WR), 15-16, Jhalana Dungari, Jaipur - 302 004, IN

Abstract

Ball and pillow structure present in the calcarernties of the Miliolite Formation, occuring in the river sections of Mangrol-Veraval arca in southern Saurashtra are described. The calcarernties deposited under shallow subaquous marine environment along tide dominated rivers. These tide dominated rivers were highly charged with sediments and the hydrodynamic conditions were of high energy regime. The occurrence of ball and pillow structures in the calcarenites indicate a rapid and sudden input of sediments along the tide dominated rivers probably under storm conditions.

Keywords

Sedimentary Structure, Miliolite Formation, Gujarat, Sedimentology.

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S. S. Garhia ¹, V. P. Sharma ¹, M. L. Yadav ¹

Affiliations
1 Geological Survey of India, Jhalana Dungri, Jaipur - 302 004, IN

Abstract

Occurrence of Quaternary Stromatolites is recorded and their mode of occurrence and morphology described.

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