During
the time of the dinosaurs, the area that encompasses the Great Plains
was a huge inland sea. Obviously plate tectonics played a role in
uplifting this vast area; but, "geologists
have long been puzzled by how the High Plains could be so big, so high
and so smooth. The plains descend gently from roughly 6,000 feet to
2,000 feet above sea level as they stretch for thousands of square
miles, from the Texas Panhandle to southern Montana, and from western
Kansas to the foothills of the Rocky Mountains in Colorado.
"It's
well-established that much of the West was still at sea level 70
million years ago and that tectonic shifts don't fully explain the High
Plains' altitude."
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Water Activates Faults?: A Japanese geophysicist has shown that when Serpentine is put under the same pressures and temperatures as is found at 400 miles depth in the Earth’s lithosphere, water oozes out. This supports the theory that as ‘waterlogged’ serpentine is subducted earthquake/volcanic activity is increased as water is freed. [ Note that serpentine contains 13% water by weight. This information has important implications for people living in the Pacific Northwest where the Juan de Fuca Plate is being subducted.] Discover Magazine
Water Activates Faults?: A Japanese geophysicist has shown that when Serpentine is put under the same pressures and temperatures as is found at 400 miles depth in the Earth’s lithosphere, water oozes out. This supports the theory that as ‘waterlogged’ serpentine is subducted earthquake/volcanic activity is increased as water is freed. [ Note that serpentine contains 13% water by weight. This information has important implications for people living in the Pacific Northwest where the Juan de Fuca Plate is being subducted.] Discover Magazine