Sandstones from the shale-sandstone association of Permo-Carboniferous sequence of the Kanawar Group of Spiti region are takenup for detailed petrographic and geochemical investigation. Compositionally, they are quartz-arenite, sub-litharenite and subarkose. Their chemical index of alteration (CIA) values range from 53 to 78 i.e., indicating low to intense chemical weathering. The point counts shows the presence of quartz as a dominant framework mineral with varying amounts of rock fragments (mainly chert, phyllite, gneissic components) and feldspars andindicate cratonic interior and recycled orogenon the Qt (quartz)-F (feldspar)-L (lithic fragments) triangular diagram, suggesting their derivation mostly from stable cratons. The integrated petrographic and geochemical studies suggest that sandstones from the Tethys Himalaya, Spiti region, are derived probably from a felsic (granitic) dominant source occurring to the south of the basin.
Permo-Carboniferous Sandstones, Petrography, Geochemistry, Spiti Valley, Tethys Himalaya
