We thank DST, New Delhi for the grant of funds under ILTP and SERC projects to TA. We also thank the University of Delhi for all the facilities and partial funding under the Minor Project given to TA. We thank colleagues of NGRI geochemistry laboratory for the analytical support. We thank Ms. Sangeeta Gupta for the assistance in finalising the manuscript. Mukesh Kumar Mishra is especially thanked for the help during the field work.