Geochemistry of Pakhal Shales

Geochemistry of Lower Pakhal shales shows higher content of Si0₂ and A1₂0₃ and negligible amount of CaO and Na₂O. The Cr/Ni, Ti/Zr and Zr/Y ratios and chondrite normalized REE fractionation pattern in these shales are comparable to the Post-Archaean Australian shale (PAAS) Distribution of La-Th-Sc, Th-Sc-Zr/lO and Ti/Zr vs La/Sc ratios and association of these shales with quartzites and dolomites indicate that they were deposited in an intracratonic basin. The study reveals that the source rocks for these sediments were granitic in composition and the adjoining Archaean gneissic terrain is the predictable provenance. The fractionated LREE and negative Eu anomaly indicates either cratonic basin or a shallow water passive continental environment during deposition.