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The Pinnacles
Crater Lake National Park, Oregon. These towering needle-like formations of rock, called fossil fumaroles, projecting from the Sand Creek Canyon floor, were formed under sheets of volcanic pumice that preceded Mazama's collapse. As the surface of the hot pumice cooled over the years, steam and gases were released by the hot rocks underneath through vents and tubes that were welded into cement hardness by their passage. These ancient vents now stand alone due to the erosion of the surrounding softer materials. (Crater Lake Institute) The Pinnacles lie at the end of a spur road that leaves from the Rim Road southeast of Crater Lake. Scanned from a Kodachrome slide. Best viewed large.
The Pinnacles
Crater Lake National Park, Oregon. These towering needle-like formations of rock, called fossil fumaroles, projecting from the Sand Creek Canyon floor, were formed under sheets of volcanic pumice that preceded Mazama's collapse. As the surface of the hot pumice cooled over the years, steam and gases were released by the hot rocks underneath through vents and tubes that were welded into cement hardness by their passage. These ancient vents now stand alone due to the erosion of the surrounding softer materials. (Crater Lake Institute) The Pinnacles lie at the end of a spur road that leaves from the Rim Road southeast of Crater Lake. Scanned from a Kodachrome slide. Best viewed large.