PALAEOMAGNETIC INVESTIGATION OF THE DECCAN BASALT LAVA FLOWS, AMBA FORMATION, CENTRAL INDIA: INSIGHTS OF TD AND AFD TECHNIQUES

Abstract

This study represents palaeomagnetic investigations of the Amba formations, utilizing magnetic and thermal cleaning techniques to differentiate primary magnetic components from secondary ones. The study area is a part of Deccan Volcanic Province (DVP) and comprises lava sequence of 400 meter thickness. Total 38 representative specimens were analyzed to assess the stability of their natural remanent magnetization (NRM) using alternating field demagnetization (AFD) and thermal demagnetization (TD). The results of alternating field demagnetization reveal different behavior, with some samples retaining stable NRM directions and others indicating significant secondary components. The thermal demagnetization technique demonstrated three distinct patterns of magnetic behavior, from steady intensity decreases to initial increases, followed by gradual decreases, and steep initial falls indicating strong isothermal remanent magnetization. These findings highlight the effectiveness of AFD and TD in identifying primary magnetization and provide a foundation for correlation of the lava flows, exposed all over the globe.