期刊名称：International Research Journal of Earth Sciences
电子版ISSN：2321-2527
出版年度：2014
卷号：2
期号：4
页码：1-12
语种：English
出版社：International Science Community Association
摘要：Geologically, Purulia district of West Bengal is dominated primarily by granite gneiss rocks. Proterozic hard granite gneiss and migmatite are the principal rock types found in Manbazar while Proterozic soft, flaky phyllite and mica schist belonging to the Singhbhum Group, composed of quartz, muscovite and biotite mica, are the dominant rocks in Banduan area. The present study examines the geochemical alteration of rocks and minerals and transport of weathering end products at Manbazar and Banduan sample sites in relation to spatial variability in geological setting and differential response of rocks to weathering-denudation processes. Variations in geochemical and mineralogical characteristics were measured through weathering sequences exposed near Manbazar and Banduan in Purulia district. Altogether 14 weathered rock samples were collected from 3 weathering profiles and were analyzed mineralogically by X-Ray diffraction (XRD) technique. The major primary minerals identified in the weathering crust of granitic rocks are quartz, muscovite, feldspar and biotite. The dominant secondary minerals are kaolinite, montmorillonite and illite. Quartz is found in all the sequences of weathering crust for its poor susceptibility to chemical weathering. The occurrence of Phyllosilicate clay minerals in all the weathering facies in the study area is indicative of an intensive weathering under tropical humid climate leading to the development of weathered crust.
