Neoproterozoic Palaeomagnetic Results of Jodhpur Sandstone, Marwar Supergroup, Western Rajasthan

The Jodhpur Sandstone (Marwar Supergroup) is investigated from three sites in western Rajasthan, India, using thermal and AF demagnetization techniques. The Characteristic Remanent Magnetic (ChRM) direction isolated is having a normal polarity of Dm=19.59°, Im=+46.27° (K=206.19, α₉₅= 5.63°, N=3) and yielded a Virtual Geomagnetic Pole (VGP) at λp=32.4° S, Lp = 51.3° E (δp=4.63°, δm=7.22°). The palaeomagnetic data of the Jodhpur Sandstone is in good agreement with that of the Upper Rewa Sandstone of the Vindhyan Supergroup rocks that are correlated with the Jodhpur Sandstone on lithological similarities. The Malani Rhyolite overlain by the Jodhpur Sandstone with well constrained radiometric and palaeomagnetic results thus assign a maximum age of < 745±10 Ma to the Jodhpur Sandstone and in turn to the Rewa Sandstone of the Vindhyan Supergroup which were correlated with them. This correlation helps in constraining the age of the Rewa Group rocks in the Upper Vindhyans, which are devoid of any fossil evidence and suitable radiometric material to date them.