Using a scenario already proposed by Empedocles, the emerged sing

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S. Yadav Department of Earth and Planetary Sciences, Nehru Science Center, University of Allahabad, Allahabad-211002, India The Archean stromatolites are rare and reported from 48 locations from different parts of world with an age range between 2,500 and 3,500 Ma (Schopf et al. 2007). The present study reports the first occurrence of stromatolites in calc-silicate lithology (N 25°18′14.9″, E 78°05′32.2″; elevation: 312 ± 10.9 m) occurring 4.4 km WNW of Dhala, Shivpuri District, Madhya Pradesh State, India. The calc-silicate lithology occupies nearly 4.3 km2 area. The calc-silicate rocks form linear, low-lying, and blocky outcrops. It is intimately associated with diorite in the north, and intrusive micro-granites of its southern part. The calc-silicate rock is light greenish grey in colour with alternating moderate to dark bands of variable thickness and comprises Erismodegib price quartz + hornblende + alkali feldspar + diopside ± zircon ± epidote ± sericite ± calcite ± opaque. The stromatolite-bearing calc-silicate rock is older than the host granitoids (2.5 Ga). It is interesting to note that, the stromatolite-bearing calc-silicate rock is one of the pre-impact rock types associated with a newly discovered Dhala impact structure (N 25°17′59.7″ and E 78°8′3.1″) of Paleoproterozoic age (Pati 2005 and Pati et al., in press).

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