Formation of lateritic kaolin deposit over hoskote-Kolar granodiorite: A case study from nandigudi and bavanhalli localities, Kolar District, Karnataka Meshram Rajkumar1,2, Bhondwe Abhijeet1,3, Jawadand Sanjeevani1, Raut Tejashree1, Dandekar Sneha1, Joshi Vaibhav1, Randive Kirtikumar1,* 1Department of Geology, RTM Nagpur University, Nagpur 2Geological Survey of India, State Unit, Assam, Guwahati 3Government College of Engineering, Karad, Maharashtra *Email: randive101@yahoo.co.in
Online published on 22 May, 2019. Abstract The lateritic kaolin deposits occur as a capping over isolated mounds having the basement of late Archaeangranodiorite (Hoskote-Kolar Granodiorite) at Nandagudi and Bavanhalli areas in Kolar district of Karnataka, India. These deposits are characterized by the presence of kaolinite, hematite, quartz, goethite, and anatase. Chemical data show that kaolin is composed mainly of SiO2 and Al2O3, other oxides being present in trace amounts. Fe2O3 has a variable concentration in kaolin. The observed depletion in Mn, Mg, Ca, Na, and K reflects the extent of kaolinization. Ti enrichment is evidenced in the form of anatase. Kaolinization and weathering processes have enriched Ni and Cr in the lateritic kaolin deposit. The REE pattern and the concentration of other trace elements show evidence of alteration and weathering processes related to kaolinization. The parent rock, Hoskote-Kolargranodioriteis characterized by the presence of mafic enclaves. It was observed that kaolinization process operative over the host granodiorite was co-eval with localized lateralization of the mafic enclaves in granodiorite. This simultaneous process has resulted in formation of the Nandagudi-Bavanhalli lateritic kaolin. Top Keywords Lateritic Kaolin, Kaolinization, Geochemistry, Lateritisation, REE. Top |