The Geography of the Puranas c13.s7.1

c13.s7.1

It would be interesting to compare the Purāṇic concept of cosmic cycles and evolution of life with what is now believed to be the probable history of the earth since it was born. Modern geology, on the basis of uranium-lead ratios, deduces that the approximate age of the earth is about 2,000 million years, and during this period of 2,000 million years the face of the earth has been changing constantly. The primeval granitic crust of the earth was eroded by denuding agents like water, wind, running water, etc., and sediments were laid down in the primeval oceans. This extensive period of sedimentation was evidently followed by the revolutionary crumbling of the earth's crust known as the Laurentian revolution during which large masses of molten granite were poured over these layers while the layers themselves were uplifted and folded into gigantic mountains. It must, however, be noted that this revolution need not have been the first one to take place on the surface of the earth. In fact, there probably were several earlier outbursts of tectonic activity of which we have no record.