Paper No. 9
Presentation Time: 4:00 PM
INDIA'S PLACE IN THE PROTEROZOIC WORLD: CONSTRAINTS FROM THE LARGE IGNEOUS PROVINCE [LIP] RECORD
The Large Igneous Province (LIP) record is a key tool for paleocontinental reconstruction {2, 6}. We herein consider the record of LIPs & LIP-fragments from India (based mainly on dykes & from the Dharwar craton, except where noted): 2367 Ma (U-Pb) {10, 8}; 2180 Ma (U-Pb) {15, 8} & also possibly in Bundelkhand craton {18}; 1880 Ma {4, 1} & also in Bastar craton {9}; ca. 1600 Ma volcanics in Singhbhum craton (e.g. {16}); ca. 1490 Ma {4}; ca. 1350 Ma in E. Ghats {13}; ca. 1370 & 1330 Ma {4}; ca. 1200 Ma {4, 17}; ca. 1100 Ma kimberlites {12}; 930 & 790 Ma (U-Pb) anorthosites in E. Ghats {11}; and 770-755 Ma (U-Pb) volcanics in Aravalli craton {19}. Comparison with Other Blocks {6, 5, 7, 20}: The 2367 Ma event is so-far unique, and any other block found with this age must have been a nearest neighbor. The major 2180 Ma event can potentially be matched with events on Superior {3}, Slave {3}, or West Africa cratons {5}. 1880 Ma magmatism is found on many other blocks (e.g. Superior, Slave, Wyoming & Kalahari) and perhaps more than one 1880 Ma centre is implied. Mesoproterozoic events at ca. 1600, 1490, 1350, 1200 & 1100 Ma show most similarities to Australia, but there are matches with Laurentia & Kalahari. The Neoproterozoic events can be linked to Rodinia breakup {14, 7}. Additional precise U-Pb & Ar-Ar dating (& coordinated paleomagnetism) are needed to definitively determine India's place in the Proterozoic world. REFS.: {1} Anand et al. 2003 J. Petrol 44: 2139. {2} Bleeker & Ernst 2006 in: Hanski et al. (eds.) Taylor & Francis, London. {3} Buchan & Ernst 2004 Geol. Surv. Can. Map 2022A. {4} Chatterjee & Bhattacharji 2001, Proc. Indian Acad Sci (EPS) 110: 433. {5} Ernst & Buchan 2001 In: GSA SP 352: 483. {6} Ernst & Bleeker 2007 {abstr} www.NUNA2007.ca. {7} Ernst et al. 2007 Prec. Res (in press). {8} French et al. 2004 GSA Abstr 36: 340. {9} French et al. 2004 GCA, 68 Supl 1: A586. {10} Halls et al. 2007 Pre. Res 155: 47. {11} Krause et al. 2001 Prec. Res 109: 25. {12} Kumar et al 2007 Prec. Res 154: 192. {13} Kumar et al 2007 Lithos (in press). {14} Li et al. 2007 Prec. Res (in press). {15} Pandey et al. 1997 Prec. Res 84: 181. {16} Patranabis-Deb et al. 2007 J. Geol. 115: 407. {17} Pradhan et al. 2007 {abstr} GSA ann mtg. {18} Rao 2004 Gond. Res. 7: 1219. {19} Torsvik et al. 2001 Prec. Res 108: 319. {20} www.largeigneousprovinces.org.