Portal de Periódicos da CAPES

Superposed Folding in the Aravalli Rocks of the Type Area around Udaipur, Rajasthan

1971; Springer Science+Business Media; Volume: 12; Issue: 4 Linguagem: Inglês

10.17491/jgsi/1971/120404

0974-6889

A.B. Roy, B. S. Paliwal, O. P. Goel,

earthquake and tectonic studies

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 (F 1 , F 2 and F 3 ). The earliest folding movement (F 1 ) produced tight to isoclinal folds with drawn-out hinges. The F 1 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 (F 2 ) refolded the F 1 folds to upright, open to occasionally isoclinal folds. The F 2 folds have variable plunge and an overall northerly axial trend. The third fold movement has resulted in the formation of tight to isoclinal folds (F 3 ) of small and intermediate scales on the limbs of larger F 2 folds. The F 3 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.