Publication Abstracts
Malone et al. 2008
Malone, S.J., J.G. Meert, D.M. Banerjee, M.K. Pandit, E. Tamrat, G.D. Kamenov, V.R. Pradhan, and
, 2008: Paleomagnetism and detrital zircon geochronology of the Upper Vindhyan Sequence, Son Valley and Rajasthan, India: A ca. 1000 Ma closure age for the Purana Basins? Precambrian Res., 164, 137-159, doi:10.1016/j.precamres.2008.04.004.The utility of paleomagnetic data gleaned from the Bhander and Rewa Groups of the "Purana-aged" Vindhyanchal Basin has been hampered by the poor age control associated with these units. Ages assigned to the Upper Vindhyan sequence range from Cambrian to the Mesoproterozoic and are derived from a variety of sources, including 87Sr/86Sr and δ13C correlations with the global curves and Ediacara-like fossil finds in the Lakheri-Bhander limestone. New analyses of the available paleomagnetic data collected from this study and previous work on the 1073 Ma Majhgawan kimberlite, as well as detrital zircon geochronology of the Upper Bhander sandstone and sandstones from the Marwar SuperGroup suggest that the Upper Vindhyan sequence may be up to 500 Ma older than is commonly thought. Paleomagnetic analysis generated from the Bhander and Rewa Groups yields a paleomagnetic pole at 44°N, 214.0°E (A95 = 4.3°). This paleomagnetic pole closely resembles the VGP from the well-dated Majhgawan intrusion (36.8°N, 212.5°E, α95 = 15.3°).
Detrital zircon analysis of the Upper Bhander sandstone identifies a youngest age population at not, vert, ∼1020 Ma. A comparison between the previously correlated Upper Bhander sandstone and the Marwar sandstone detrital suites shows virtually no similarities in the youngest detrital suite sampled. The main 840-920 Ma peak is absent in the Upper Bhander. This supports our assertion that the Upper Bhander is older than the 750-771 Ma Malani sequence, and is likely close to the age of the 1073 Ma Majhgawan kimberlite on the basis of the paleomagnetic similarities. By setting the age of the Upper Vindhyan at 1000-1070 Ma, several intriguing possibilities arise. The Bhander-Rewa paleomagnetic pole allows for a reconstruction of India at 1000-1070 Ma that overlaps with the 1073±13.7 Majhgawan kimberlite VGP. Comparisons between the composite Upper Vindhyan pole (43.9°N, 210.2°E, α95 = 12.2°) and the Australian 1071±8 Ma Bangamall Basin sills and the not, vert, ∼1070 Ma Alcurra dykes suggest that Australia and India were not adjacent at this time period.
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BibTeX Citation
@article{ma00700d, author={Malone, S. J. and Meert, J. G. and Banerjee, D. M. and Pandit, M. K. and Tamrat, E. and Kamenov, G. D. and Pradhan, V. R. and Sohl, L. E.}, title={Paleomagnetism and detrital zircon geochronology of the Upper Vindhyan Sequence, Son Valley and Rajasthan, India: A ca. 1000 Ma closure age for the Purana Basins?}, year={2008}, journal={Precambrian Research}, volume={164}, pages={137--159}, doi={10.1016/j.precamres.2008.04.004}, }
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RIS Citation
TY - JOUR ID - ma00700d AU - Malone, S. J. AU - Meert, J. G. AU - Banerjee, D. M. AU - Pandit, M. K. AU - Tamrat, E. AU - Kamenov, G. D. AU - Pradhan, V. R. AU - Sohl, L. E. PY - 2008 TI - Paleomagnetism and detrital zircon geochronology of the Upper Vindhyan Sequence, Son Valley and Rajasthan, India: A ca. 1000 Ma closure age for the Purana Basins? JA - Precambrian Res. JO - Precambrian Research VL - 164 SP - 137 EP - 159 DO - 10.1016/j.precamres.2008.04.004 ER -
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