Age of Indian basins may be off by millions of years

January 20, 2009

After researching for six weeks in India, geologists believe they have been wrong from the beginning, literally.

A team of geologists studying the Vindhyan basin of India has dated the area to be about 1,073 million years old. Fossil organisms in these basins are also significantly older than previously thought.

Until this discovery last July, the basins of Central India were believed to have formed 500 million to 700 million years ago during the Ediacaran and Cambrian period.

“The possibility that organisms in this basin are much older than originally thought was the most interesting implication of the study,” said Joe Meert, a University of Florida geology professor and leader of the team who made the discovery.

The geologists were able to establish a date of origin of the basin through a combination of dating methods using kimberlite, a volcanic rock containing diamonds, and zircon minerals found within the sandstones in the basin.

The 500-million-year discrepancy is controversial in the science world.

The findings could alter aspects of the theory of evolution. Scientists have always believed in a Cambrian explosion resulting in a rapid appearance of most major groups of complex, multi-cellular animals, Meert explained.

Yet multi-cellular life, in the form of soft-bodied Ediacaran organisms, was discovered in the Vindhyan basin, leading Meert and co-authors to suggest that the explosion may have been more of a slow burn.

The study also helped reconcile an inconsistency in the Snowball Earth hypothesis that states the Earth was covered in snow and ice from 635 million to 700 million years ago.

A major roadblock for this hypothesis had been that the Vindhyan and other Purana basins did not have signs that glaciers existed during that period. Now that the origins of these basins have been pushed back to before Snowball Earth, the lack of glacial evidence is no longer problematic.

Information from the study appeared in the online and print editions of the journal Precambrian Research, as well as in National Geographic and The Christian Science Monitor.

“In modern geology, a 500-million-year revision in age is pretty unique,” Meert said.