Flow-by-Flow Paleofield and Virtual Dipole Moment Analysis in the Mandla Lobe, Eastern Deccan Volcanic Province

Understanding Earth’s geodynamo processes is challenging due to limited data and the inaccessibility of Earth’s deep interior. Investigations of the Virtual Dipole Moment (VDM) and magnetic field intensity (paleofield) from continental flood basalts, such as the Deccan Volcanic Province (DVP), serve as valuable proxies for understanding past magnetic field behavior and core-mantle boundary (CMB) interactions. This study presents the first attempt to determine flow-by-flow paleofield and VDM analysis through progressive AF and thermal demagnetization of 36 distinct lava flows from the Mandla lobe, eastern DVP. Reliable mean VDM and paleofield values were calculated based on specimens that met reliability criteria and were globally correlated with the PINT database. The mean VDM value obtained from the eastern DVP is 1.58 ± 0.43 × 10²² Am², which aligns with VDM values reported from the Koyna region, western DVP, indicating a persistently weak Earth’s magnetic field across the DVP. The lowest VDM value of 0.62 ± 0.19 × 10²² Am², obtained from eight physically distinct lava flows of intermediate polarity, suggests these flows erupted during periods of weak Earth’s magnetic field, implying non-sudden polarity reversals.