Superposed Folding in the Aravalli Rocks of the Type Area around Udaipur, Rajasthan
Authors
-
Department of Geology, University of Rajasthan, Udaipur
A. B. Roy -
Department of Geology, University of Rajasthan, Udaipur
B. S. Paliwal
-
Department of Geology, University of Rajasthan, Udaipur
O. P. Goel
Abstract
Around Udaipur, the Precambrian rocks belonging to the Aravalli System are represented by feldspathic greywacke grading to phyllite and mica schist, calc-arenite, and ferruginous and carbonaceous quartzites. The rocks display a high degree of structural complexity resulting from the impress of three distinct periods of folding (F1, F2 and F3). The earliest folding movement (F1) produced tight to isoclinal folds with drawn-out hinges. The F1 folds are accompanied by a set of very well developed axial plane schistosity. These folds are presumed to have been initially recumbent with E-W to NW-SE axial trend. The second fold movement (F2) refolded the F1 folds to upright, open to occasionally isoclinal folds. The F2 folds have variable plunge and an overall northerly axial trend. The third fold movement has resulted in the formation of tight to isoclinal folds (F3) of small and intermediate scales on the limbs of larger F2 folds. The F3 folds are characterized by a set of axial plane crenulation cleavages. The superposition of the three fold systems has resulted in complex interference patterns on different scales.Downloads
Issue
Section
Downloads
Published
How to Cite
References
de SITTER, L. U., (1954) Schistosity and Shear in Micro and Macrofabncs. Geol Mijnbouw, v. 16, pp. 429-439.
FLEUIY, M. J., (1964) Description of Folds. Geol Assoc. Proc, v. 75, pp 461-492.
GREENLY, E, (1919) The Geology of Anglesey. Mem. Geol. Surv Gt Bntain, v. 1, pp. 1-980.
HERON, A. M., (1953) The geology of central Rajputana. Mem. Geol. Surv. India, v. 79, pp. 1-389.
KNILL, J. L, (1960) A classification of cleavages, with special reference to the Craignish District of the Scottish Highlands. Int. Geol. Cong , XXI Session Pt. 18, pp. 317-325.
MCINTYRE, D. B, (1951) The tectonics of the area between Grantown and Tomintoul (mid-Strathspey). Quart. J. Geol. Soc. London, v. 107, pp. 1-22.
NAHA, K, CHAUDHURI, A. K. and BHATTACHARYYA, A. C., (1966) Superposed folding in the older Precambrian rocks around Sangat, central Rajasthan, India. Neues. Jahrb. Geol. Palaeont Abh., v. 126, pp. 205-231.
NAHA, K, CHAUDHURI, A. K. and BHATTACHARYYA, A. C., and MUKHERJI, P., (1969a) Analysis of large scale superposed folding in a migmatite terrain Geol. Mijnbouw, v. 48, pp. 9-34.
NAHA, K, CHAUDHURI, A. K. and BHATTACHARYYA, A. C., VENKITASUBRAMANYAN, C. S. and SINGH, R. P., (1969b) Upright folding of varying intensity on isoclinal folds of diverse orientation a study from the early Precambrians of western India. Geol Rundschau, v. 58, pp. 929-950.
PODDAR, B. C, (1966) An example of contrasted tectonic legimes from the Precambrians of Udaipur Dist, Rajasthan. Ind. Minerals, v. 20, pp. 192-194.
RAMSAY, J. G., (1962) Interference patterns produced by superposition of folds of similar type. J. Geol, v. 70, pp. 466-481.
RAMSAY, J. G., (1967) Folding and Fracturing of rocks, McGraw-Hill Book Company.
RICKARD, M. J., (1961) A note on cleavage in crenulated rocks. Int. Geol. Cong., XXI Session Pt. 18, pp. 317-325.
SUTTON, J., (1960) Some Crossfolds and related structures in Northern Scotland. Geol. Mijnbouw, v. 39, pp. 149-162.
TURNER, F. J. and WEISS, L. E., (1963) Structural analysis of Metamorphic tectonites. McGraw-Hill Book Company.
WEISS, L. E. and MCINTYRE, D. B., (1957) Structural geometry of Dalradian rocks at Loch Leven, Scottish Highlands. J. Geol, v. 65, pp. 590.
WEISS, L. E., (1959) Geometry of superposed folding. Bull. Geol. Soc. Amer., v. 70, pp. 91-106.
