Pillow Lavas from Delhi Supergroup near Bambholai, Pali District, Rajasthan

Abstract

Three flows have been delineated on the basis of quartzite and phyllite interbeds. The lowermost flow shows few isolated pillows enclosed in subaqueous breccia while the upper flows are mostly pillow breccia showing isolated and close-packed pillows. Well developed pillows are elliptical to circular in shape and show radial joints and chilled glassy crust of variable thickness. Vesicles, amygdules and geodes of variable shapes and sizes are quite common. The hyaloclastite, filling the interspaces between pillows, is composed of light brown to dark glassy fragments and grades to breccia with increase in size of the fragments.