Paleomagnetic approach for Geomagnetic excursions, Paleointensity, Paleolatitude and Paleoclimate (Ge3P) reconstruction

Chief Coordinator : B.V. Lakshmi & Members

The strength of Earth’s magnetic field changes in an unpredictable manner. Understanding these changes requires precise information on how the field has changed in the past. Direct instrumental measurements of magnetic field intensity began in the 1840s, providing only a short time window into past intensity changes. Accurate and reliable magnetic records have been available since the establishment of magnetic observatories in the early nineteenth century, before which geomagnetic field changes could be indirectly deciphered from archaeological materials, volcanic rocks, and sediment formations. Paleomagnetism is a valuable tool for understanding Earth’s historical magnetic field, which can provide insights into geomagnetic excursions, paleointensity, paleolatitude and paleoclimatic reconstructions.  Geomagnetic excursions are temporary deviations in the Earth’s magnetic field from its normal state, typically characterised by a significant change in direction and intensity. The timing and characteristics of these excursions can be correlated with geological and climatic events, providing insights into the behaviour of the geomagnetic field over geological time. The archaeomagnetic study to bring out the past geomagnetic information on Indian archaeological artefacts is very scarce. By studying archaeological artefacts by using modern geophysical instruments available at IIG Environmental Magnetism Laboratory, it is possible to establish the secular variation of Earth’s magnetic field over the Indian subcontinent. 
Detailed paleomagnetic data is lacking for the Rajmahal Traps (RT)-Sylhet Traps (ST) magmatic domain, which is essentially required for a better understanding of the reconstruction of paleo-continental supercontinents. Dykes/sills/flows, which are considered to be parts of a Large Igneous Province (LIP) plumbing system, are important magmatic emplacement and can be studied for their paleomagnetic, geochemical, and geochronological investigations to place constraints on the position and extent of subcontinents in the geological past. The Arabian Sea region is strongly influenced by the modern South Asian monsoon (SAM), which is a dominant vector for the transport of heat and moisture in tropical low latitudes. The detailed literature survey revealed that environmental magnetic studies from the eastern and western the Arabian Sea is lacking. The detection and abundance of bacterial magnetite can help in understanding the oxygen minimum zone in the Arabian Sea and contribute in the understanding of the SAM evolution. 
     The main objectives under this program are, to reconstruct a high-resolution absolute paleo-intensity curve using archaeological artefacts, relative paleointensity (RPI) and geomagnetic excursions using the lacustrine sediments, understanding the timing and evolution of the Greater Kerguelen magmatic chambers using the geochronology and paleomagnetism of the Sylhet and Rajmahal Traps, and to study the Oxygen Minimum Zone (OMZ) variability in the western and eastern Arabian Sea using magnetofossils record.

 Chief Coordinator : B.V. Lakshmi 
Coordinator(s) : Priyeshu Srivastava
Members : B.V. Lakshmi, K. Deenadayalan, Priyeshu Srivastava, Ramesh K. Nishad,  Anup K. Sinha, Sujit K. Pradhan, E. Karthikeyan,  Gautam Gupta and Project staff

{updated on 31-07-2024}