Andesite Boulders

The rocks along the high slopes of Park Ridge are known as andesite, and are the predominant form of volcanic rock in the High Cascades. The name comes from the Andes range in South America, which mirrors the Cascades in its origin and form along the geologically active Pacific Rim. The odd shape of these boulders results from spalling, a process where newly exposed rock splits upon being exposed to the elements. It also makes for a welcome lounge chair, as Jon demonstrates.

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All images are ©Tom Kloster 2001, and may not be used without permission