PALEOMAGNETIC STUDY OF MAFIC DIKES IN INDIA: IMPLICATIONS FOR SUPERCONTINENT ASSEMBLY AND DISPERSAL

The proposal of a Precambrian supercontinent and the Neoproterozoic assembly of Gondwana is under considerable debate and surrounded by questionable data. India is crucial to this topic. In proto-Gondwana reconstructions, the location of the central Indian craton is important in testing the existence and age of the proposed supercontinent. Improved paleomagnetic data and geochronology collected from numerous dikes in central India will help to better constrain the existence of the supercontinent. We have sampled from the following areas: (1) 4 dikes from the Malani igneous site in Rajasthan, which includes a baked contact test, dated 750 Ma to 771-750 Ma (2) 70 samples from 6 different sites from Gwalior in Madhya Pradesh, dated 1830± 200 Ma (3) 15 dikes with baked contact from Bundelkhand in Madhya Pradesh dated between 2.0 to 2.15 Ga and (4) 17 dikes from the Newer dolerites in Jharkhand dated 1500 to 950 Ma (5) samples from Majhgawan kimberlite in Madhya Prodesh dated between 847 and 1630 Ma. Paleomagnetic data from many of these sites have been previously collected but, in some cases the data were poorly documented. Not enough samples were taken from too few sites and modern demagnetization techniques were not utilized. Age constraints were also inconclusive. Therefore we have undertaken a much more thorough resampling of the area for geochronology and paleomagnetic analysis. We will present preliminary paleomagnetic and geochronologic data.