This proposal will allow the principal investigator and his colleagues to determine the paleogeographic position of India in relationship to other continental masses during the time period from 700 to 2100 million years ago. The research will be based on a combination of geochronological and paleomagnetic studies on rocks from central and southern India and will involve a collaborative effort between Indian and U.S. scientists. This particular interval of geologic time is significant because it encompasses at least two episodes of severe (global?) glaciations; a period of time where the continents may have moved, in unison, at velocities much faster than those witnessed at other times in Earth history (via true polar wander); the formation and destruction of two supercontinents (Columbia and Rodinia) and it also preceded the explosion of life in the Cambrian. The results will allow the researchers to examine possible relationships between paleogeography, climate and biological evolution during one of the most unusual periods in Earth history. For example, it has been proposed that the breakup of the supercontinent Rodinia was preceded by a rapid interval of continental motion and also that this breakup provided a trigger for one of the 'Snowball' glaciations. These 'Snowball' glaciations in turn created an ecologic bottleneck for the extant organisms and may have triggered a unique biological adaptation leading to the Cambrian explosion.
