Canyons

Well my impression of Texas not having mountains was blown away last week, now my impression of Texas not having canyons has also been wiped out.  The geology of Texas has several episodes of limestone formation, sedimentary deposition, volcanic lava flows, and erosion.  Recently (maybe the last few million years) the limestone layers have been carved out by river flows, leaving deep canyons.  The canyon walls are so tall and steep, that the border patrol doesn't even worry about immigrants crossing here.  The prettiest canyon was Eagle Nest Creek.

It's not very deep compared to the Pecos River, but the steep canyon walls and bushes along the bottom make for a nice picture, even on a rainy day.  The canyons befuddled the railroad engineers for quite awhile and you can see the most recent attempt across Eagle Nest Creek here.

 



One thing that was quite striking was the sharp transition in color between rock layers where they were cut into by the road building.  Not sure how the geologists say this happened, but one guess is that the lighter limestone layer was deposited on the floor of a shallow sea and then was eroded, followed by another deposition of different material from a different sea.

The Pecos River flows into the Rio Grande River, and it is backed up by the Amisted dam on the Rio Grande.



The highway bridge is quite the cantilever structure.

Caves in the limestone wall show the power of moving water in carving the steep cliffs.

So, again my naïve assumptions of what Texas looks like are changing.  I think that Texans want everyone to think that it's just flat, dry rangeland - that's what will keep invaders from the north-49 out!