Land Masses Riding on Plates of Earth’s Crust

Black Mountain was a tropical island near the equator. Santa Cruz was a suburb of Bakersfield.

That was the way things were around here 100 million years ago, says Prof. Alan Cox, dean of the Stanford University School of Earth Sciences.

About 60 million to 70 million years ago, Black Mountain sat on an oceanic plate near the equator that shifted slowly northeast until it bumped into North America.

The 2,787-foot peak was lopped off and landed where it is now--the tallest of the foothills near the Stanford campus about 15 miles west of the Pacific Ocean.

“We know that Black Mountain is completely out of place and that it did not form anywhere near North America,” Cox said. “Limestone like that in Black Mountain forms only in tropical waters, so Black Mountain was originally a tropical island.”

According to the theory of plate tectonics, accepted only about two decades ago, the Earth’s land masses are riding on great plates of the Earth’s crust that are constantly moving, Cox said.

“Virtually the entire Pacific Coast from Baja in the south to the tip of Alaska and extending inland an average distance of some 500 kilometers was grafted onto the pre-existing continent in a piecemeal fashion,” he said. “Thus, 10 million years ago, Santa Cruz was a suburb of Bakersfield.”