Petrography and Geochemistry of Sullavai Sandstones of Kanpa-Tempa, Chandrapur District, Maharashtra, India

The data on petrography and geochemical behaviour of Neoproterozoic siliciclastic sandstones of Kanpa-Tempa area from Chandrapur District are presented here to determine the provenance, source rock weathering and tectonic setting. The major elemental composition reveals that the Neoproterozoic sandstones are mainly as litharenite. The interrelationship of Zr vs. TiO2, Y/ Ni vs. Cr/V, TiO2 vs. Al2O3, high LREE/HREE ratios (8.97 to 12.46) and negative Eu anomalies (Eu/Eu*= 0.52 to 0.79) suggest that the sandstones were mainly derived from the parent felsic igneous rocks. The higher values of paleo-weathering indices such as Plagioclase Index of Alteration (PIA), grading from 66.42 to 80.82 and Chemical Index of Weathering (CIW), ranging from 70.58 to 82.39 clearly point out that the sediments and their source rocks experienced moderate to intense weathering. The Chemical Index of Alteration (CIA) values (ranging from 62.79 to 76.16) coupled with average content of K2O (1.66) is indicative of K-addition during diagenetic processes. Similarly lower values of K2O/Na2O ratio (0.52) suggest limited chemical maturity and SiO2-K2O/Na2O discrimination plot exhibits the active continental marginal tectonic settings.