August 13, 2003

The Bedrock of the United States

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Geology of the Conterminous United States at 1:2,500,000 Scale

The present Geologic Map of the United States follows the same format as the preceding Geologic Map of the United States of 1932. Ideally, both have been designed to represent the geological features that the user could find if he should visit any locality within its limits, that is, the bedrock formations that lie at the surface at that locality. In many parts of the country, especially in the arid regions of the Southwest, this is literally true. In other parts of the country there are lesser or greater departures from this ideal, owing mainly to concealment of the bedrock by surficial material.

Posted by Vanderleun at August 13, 2003 11:39 AM
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