Monday, August 25, 2014

Rocks...


 Guadeloupita Mesa. The orange layers (starting at the bottom) are the Abo Formation, Lower Yeso, a little bit of the remaining Upper Yeso which has been eroded and topped over by the Bandolier Tuff which is all of the buff colored rocks.

The other side of Guadeloupita Mesa. Starting at the bottom is the orange Lower Yeso (the Abo doesn't show at all) a complete Upper Yeso which is the fine layers of darker red.  The Glorieta sandstone is the light and dark, relatively chunky layer about half the thickness of the Upper Yeso.   Above the Glorieta sandstone is layer that is eroded and looks like a bit of a slope with vegetation, that's the Moenkopi formation. (I looked up how to spell that.  The last dark sandstone/conglomerate layer is the Chinle Group.  Above that is the Bandolier Tuff. 

In between the two pictures is fault displacement of maybe a 100 meters.  On the left everything above the Upper Yeso is gone, eroded away before the mega-volcano covered it all.

 This view is from the top of Sandia Crest and shows the Madera limestones.   These are actually *below* the Abo formation at the very bottom of the mesa in the first pictures.  But they've been uplifted to the very top of the Sandia mountains.















Purple asters on Sandia Crest.  And another picture of the layers of limestone and the weathered granite below.  The exciting part (I am assured) is that the granite is 1.4 billion years old and the limestone laying directly on top of it is 300 to 318 million years old.  There is 1.1 billion years of rock that is missing between them.
















Another shot of the Abo formation... the one that would be directly on top of the Madera and I suppose if a person dug a deep hole they'd find it there.  The Abo is a lot of mudstone and flood plain rocks with layers of sandstone between and breaks up sort of easily... the pillar is impressive, but probably won't last for many more years.


And last, more flowers.  Apache plume.

Also... I realize most people don't care AT ALL what names go with layers of rock, but I'm going to have to remember all of this so I'm mostly repeating it all for my own benefit.

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