Yellowstone National Park, Part 1

» led2 - island park caldera

I live summers in the penultimate caldera -- our home is 30 miles southwest of West Yellowstone.
Habiger's article is terrific -- gives a great overview of this area -- but many questions remain.
My current favorites are: what happened to the north rim? Is Henry's Lake within the IP caldera? Is West Yellowstone within either caldera, or is it outside both?
All this on top of "I'm unclear on the chronology -- is it "eruption, tectonic movement, fault thrust (creating surrounding mountain peaks), glacier"?
Thanks for all info.

-- posted by led2

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» paleogeoff - Re: island park caldera

In response to message posted by led2:

Let's see. First - I envy you for living in such a wonderful part of the country. I lived for 2 years in Bozeman, MT and enjoyed every chance I got to travel to the Yellowstone plateau.

I think I answered the north rim question for the Island Park Caldera in my e-mail to you. Henry's Lake is outside of the Island Park (or Henry's Fork) caldera.

West Yellowstone lies outside of all the calderas that formed Yellowstone.

The basic chronology goes like this: thrust faults forAbsaroka, Tetons, Gros Ventres and other mountain ranges in Wyoming and Montana beginning around the beginning of the Cenozoic (early Tertiary). Tectonic movement (I'm assuming referring to earthquakes) has occurred simultaneously with the thrusting of the continental blocks that formed the mountains, but the most recent period of major earthquakes occurred along the Teton Fault and other faults in the area in the last 15 million years. (Movement along the Teton fault began around 13 million years ago.) The eruptions of the 3 calderas at Yellowstone started at the very end of the Tertiary Period, 2.1 million years ago. This has been the most recent eruptions of the hot spot which started its journey about 16 million years ago under what is now eastern Washington and western Idaho. Finally, the glaciers formed over the high spot created by the uplift of the plateau beginning around 1.6 million years ago, forming and retreating several times until the most recent glaciation that ended around 10-12 thousand years ago.

I hope this helps answer your question on the chronology. Thanks for the support - and I hope you continue to find useful information.

Geoff

-- posted by paleogeoff

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