Yeah, I know, I know – I was on the Slack-Jaw Tour bus but yesterday we zoomed all the way up into the realms of Utterly Blown Mind. How? Emmmmm…Painted Hills, fossil beds, Badlands...Imma let Ten say a few words about these pics. The man knows his geologic history!
Take it away, Ten!
First: it is my long standing conviction that we cannot even begin to
understand the world until we can grasp geological time. The Painted
Hills (above and left) puts it all out there to see: forty-five million years of history,
seven volcanic epochs, three climate changes and two ice-ages.Palisades and vents (at right) are the youngest, hardest rock that remain when a vent has exhausted itself. Like a plug, it is the last to "erode" or shake away.
Though
formally a part of erosion, erosion as we think of it – wind and water –
is not the primary factor in the landscape. Out here we shake,
everyday, to low intensity earthquakes in the 2.0 to 3.0 range on the
Richter Scale. What has happened over millions of years is not unlike
shaking out a cat box through a screen: the finest stuff slides away
quickly, the larger, courser material more slowly and inconsistently,
finally leaving the largest, hardest chunks behind.
~~~
Me again – dunno if you can see them in this (or other pics) but there are ripples in the rocks, the mountains. I asked Ten was ist das? and 'the hell!? He replied:
The ripples: at the end(s) of the ice age(s), there were periods of
enormous flooding. It was during the end of the last ice age that the
Colombia Gorge (and it is thought the St. Lawrence Seaway) was carved
out as the ice dams east and northeast failed and successively spilled
the contents of great lakes sized lakes through the weakest points in
the geology. The ripples represent the water level of these successive
floodings.
~~~
What's on the Blow Donna's Mind schedule today? We'll travel through the Columbia Gorge on our way up to Vancouver, Washington where we'll visit with my fab nephew Adam and fam. Away we go!
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| I can't name them off the top of my head, but three of the volcanic epochs are remarkable by their color: a pink, a pinkish-white, and the green. |
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