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San Francisco Peak



North America 65 million years ago. For millions of years the North American continent pushed westward from what is now Europe. At the same time the Pacific Plate was raising the Rocky Mountains. Between the Adinondacks and the Rocky Mountains, extending from the Gulf Of Mexico in the south to the Arctic Ocean in the north, there was a shallow sea.

Plate techtonics far below the shallow sea lofted the land upward a mile, and slowly drained the water south into the Gulf of Mexico.

27 million years ago these overlapping plates spawned the first volcanoes  in  Arizona. This over grinding of tectonic plates continued for 6 million years, but still continues today. In time we will have more volcanoes spring up in Arizona and New Mexico, and probably Oklahoma. 

30 thousand years ago the younger volcanoes emerged to further alter the landscape. In the absence of ancient volcanic activity, Arizona would today    be an arid high plains desert.

This map marks the first volcanoes with the color brown. These volcanic fields  stretched from Mexico to Denver, Colorado, and west as far as Williams, AZ.

The mauve areas mark younger lava beds which were when formed were on top of mesas. 

Areas between the high places were soft and more easily eroded to current level of altitude, like Monument Valley for example.

More about all of that.

To summarize, the first volcano emerged near Williams, Arizona, and the last one was Sunset Crater. Sunset crater last errupted 11 hundred years ago.

That erruption buried several Indian villages with casualties unknown.

Spanning a distance of fifty miles, these craters have sprang up in a direction from west to east.

In the future, chances are that another volcano will emerge east of Flagstaff.   

More Information:

volcanoe1, volcanoe2, volcanoe3.

Potted Histories TM by donkelly.

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