Post by 1dave on Nov 16, 2018 9:40:31 GMT -5
As the Farallon Plate moved east under the western states rows of volcanoes moved east with it's leading edge.
"Ja, undt?"
But there were three hot spots that were very different.
The first appeared in central Nevada about 47 million years ago - obscured by the breakup of the area into the Basin and Range, but filled the surrounding area with silver sulfate. Over time the hot spot moved east and 33 million years ago exploded on the Nevada/Utah border, now known as the Indian Peak Caldera and Needles Range.
28 million years ago it produced the Black Rock Desert, 25 million years ago the Mt. Bellknap Caldera at Beaver Utah, and 23 million years ago, the Marysvale Volcanic Field with gold in the older eruption sequence and gold, molybdenum, uranium, and base metals in the younger.
The Second was south of there, the Willow Springs eruption 33 million years ago, close to present day Mesquite Nevada, then plowed a series of fractures, like an Ice Breaker Ship, as it initiated what is known as the "Iron Axis" from Mineral Mountain to Three Peaks west of Enoch Utah.
The Third is much better known as 16 million years ago the McDermitt eruption began the Yellowstone Sequence.
Put them all together and they spell . . .
Why the different starting times? Why the different paths?
EDIT: What do they have to do with the precious metal deposits described by Bill Wray's 4 mineral belts?
