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September 17, 2003

Appalachian Amazon

A lost Amazon of Appalachia once carried the sand which covered North America in a sea of dunes (no, not this Amazon).

Thick remnants of the 190 million-year-old sand sea are found today in the scenic, buff-colored Navajo Sandstone cliffs of Utah, New Mexico, Arizona and Colorado. By studying durable minerals in the sandstone called zircons, Yale University geologist Jeffrey Rahl and his colleagues have found a chemical signature that reveals their surprisingly distant Appalachian origin.

Posted by Ghost of a flea at September 17, 2003 08:16 AM