NASA's Curiosity Mars rover, slowly nearing its initial science destination where multiple types of terrain come together, has found outcrops of conglomerate rocks made up of eroded gravels that scientists believe were transported across the floor of Gale Crater by a "vigorous" flow of ankle- to hip-deep water in the distant past, scientists said today.
It's the first observation of its kind on Mars, showing that an alluvial fan photographed from orbit was, as suspected, formed by the action of flowing water that entered the crater through a 100-foot-deep, 2,000-foot-wide channel dubbed Peace Vallis that cuts through the crater rim and then fans out across a gentle 1-degree slope toward Curiosity's landing site.
An outcrop of conglomerate rock on the floor of Gale Crater is made up of cemented gravels that indicate an ancient flow of water downstream of a channel in the crater wall that spreads out into an alluvial fan up slope from the Curiosity rover.
(Credit: NASA)
"This rock is made up of rounded gravels in a matrix that's very sand rich," Rebecca Williams of the Planetary Science Institute in Tucson, Ariz., told reporters. "And these attributes are consistent with a common sedimentary rock type called a conglomerate.... Over time, erosion is working on that rock face and liberating some of the gravels and they're falling down and accumulating in a pile at the base of that outcrop."[Read more]
via CNET http://feedproxy.google.com/~r/cnet/NnTv/~3/8obP10ZwY9Q/
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