Patagonia site of world's biggest crater field: study

Covering 400 square kilometers (154 square miles), the Bajada del Diablo field is peppered with at least 100 depressions left by the collisions of meteorites or comets 130,000 to 780,000 years ago, the study found.

"Each crater measures between 100 and 500 meters (yards) in diameter and is between 30 and 50 meters deep, which makes it the biggest such field in the world in terms of the size of the craters," said Rogelio Acevedo of the Southern Center for Scientific Investigations.

The study, published in the September edition of the journal Geomorphology, was led by Acevedo and Hugo Corbella, who first identified the field in the 1970s.

Thirty years later, the team obtained financing from the Argentine province of Chubut and the National Geographic Society to survey the field.

In terms of the number of craters, the field is only the second largest in the world after the Sikhote-Aalin field in Siberia, which has 159 craters.

"But in Siberia the craters are smaller," Acevedo said.

With just one impact of the size that struck Patagonia, he said, Buenos Aires "would be pulverized in a matter of seconds."

He said the field's craters, which are visible on Google Earth, are similar to those found on the Moon, Mercury, Mars and Venus, making them worthy of further study.

They are well preserved because the remote sheep-raising region in which they are found is arid and sparsely populated, he said, adding that it will be necessary to protect it from tourists.

But Acevedo suggested, "this exceptional place could become a natural park."

Argentina has another crater field, called Campo de Cielo, in the northern Chaco province. There are only nine such fields in the world.

(c) 2009 AFP