Himalayan Geology, Vol. 43 (2), 2022, pp. 429-434, Printed in India
Redox state of mineralized and barren granitoids of Malanjkhand region, Central India: constraint from magnetic susceptibility and its geochemical correlation
DEEPA ARYA*, SAURABH GUPTA
Department of Geology, Centre of Advanced Study, Kumaun University, Nainital 263002, India
*Email (Corresponding author): firstname.lastname@example.org
Abstract: The Malanjkhand granitoid (MG) comprises an area of 1500 square km in the Balaghat region of Madhya Pradesh, India. It represents Paleoproterozoic felsic magmatism which hosts Cu ±(Mo±Au) deposits and is integrated with the Central Indian Suture zone. Redox conditions of Malanjkhand granitoids from both mineralized and unmineralized (barren) counterparts in terms of magnetic susceptibility (MS) has been measured and compiled in the present work. The MS values for the mineralized granitoids vary from 0.19 to 3.25 x10-3 SI units, while for barren granitoids, 0.12 to 7.17 x10-3 SI units. The MS values are used to classify the granitoids into magnetite series (≥3.0x10-3 SI units) and ilmenite series (≤3.0x10-3 SI units) granitoids, which correspond to oxidized- and reduced-type of granitoids, respectively. Significant MS variation has been noticed with variations in colour, composition and texture. More than 90% of granitoids belong to ilmenite-series granites corresponding to a reduced oxidation state of magma during crystallization. Nevertheless, similar observations have been observed from the correlation of current MS values with previously published geochemical data. However, a moderately reduced oxidation state for MG has been argued from correlation.
Keywords: Malanjkhand granitoids, Magnetic susceptibility, ilmenite-series, magnetite-series.