The Flickr Guadalupemountainsnationalpark Image Generatr

The last image in my photostream was of Pratt Cabin. This image is what their view would have been like from that front porch.

The Pratt Cabin can be found along the McKittrick Canyon Trail. It was built in the winter of 1931-1932 out of local limestone. I was particularly impressed by the stone roof, and the design of the interior that left the rock exposed. More information can be found at this link.
www.nps.gov/places/gumo_pratt_cabin.htm

These are the only remains of overland trail that swung thru the southern rim of the country. Stagecoaches, passengers, and mail moved along this route.

As I recall, this shot was taken near Stop 3, as delineated in the Texas Bureau of Economic Geology Guide to this trail.

And, by the way, xerophytic refers to plants that are well-adapted to arid climates.

This intriguing pteridophyte was to me the botanical highlight of the hike. I had never come across its kind before. It's known as the Chihuahua Scaly Cloak Fern (Astrolepis cochisensis subsp. chihuahuensis). I'm aware that some sources now place it in the genus Hemionitis, but I'm sticking with the treatment currently preferred by Southwestern-US botanists.

I had previously found one other desert-adapted fern species, in Arizona, but the discovery of this one was no less thrilling. One simply expects ferns to hang out in wetter and more wooded habitats. But this little fellow was a vivid reminder that all the major lineages of plants have found ways of accommodating themselves to remarkably diverse and challenging environments.

The Chihuahua Scaly Cloak Fern is a calciphile and particularly loves limestone substrates. And sure enough, here on the toe of the Permian reef slope, it's perched on the Lamar Limestone Member of the Bell Canyon Formation. It is also scooched in tight between a rock ledge and the pads of a Prickly Pear Cactus (Opuntia sp.).

The plant's pinnae or leaf sections are covered on top with tiny scales—one way, I gather, to cope with the relentless sunlight and the hot, desiccating air. The longest frond I found was about 6 in = 15.2 cm.

Not too long after espying this plant, I came across a larger colony of its subspecies farther up the trail, as I'll show in a post to follow. And then, the next day, I encountered it again down in Presidio County. It was growing just as happily on a roadcut of ignimbrite and other volcanic rocks of the Paisano Caldera. Apparently that lithology was sufficiently rich in calcium, too.

You'll find the other photos and descriptions of this series in my Moseying Up the Permian Reef Geology Trail album.

Lower elevations meant less clouds, giving us spectacular views of the surrounding mountains. While the snow was still heavy in the trees here, it had melted near the base.

Further down the peak as it continued to clear.

While we had been clouded in at the peak, we started to get glimpses of our spectacular surroundings as we descended. We considered ourselves lucky to be there after a snowfall.

I had to try a horizontal version of this same scene,

Leaving Carlsbad Caverns National Park the day before, we faced a rain that turned to snow. That snow continued upon our arrival at Guadalupe Mountains National Park and by the next morning it covered the ground. We decided to climb Guadalupe Peak, the highest peak in Texas, and found six inches of snow at the top, and no views as it was covered by clouds. Those clouds began to clear as we left the peak and began our descent. The Bridge is part of Guadalupe Peak Trail.

I believe that this stop is located 750 ft / 229 m up the trail from the Part 7 location. I base this entirely on the "Stop 2" description in the Guide to the Permian Reef Geology Trail, McKittrick Canyon, Guadalupe Mountains National Park, Texas of that state's Bureau of Economic Geology. It's available online here. Henceforth I'll just call it the Guide

The black object with a lanyard is a GPS receiver, a form of ancient technology that has been replaced by phones that are busily removing our last shreds of independent thought. The receiver, which is now an exhibit in the Wiggers Museum of Antediluvian Artifacts, is about 6 in / 15.2 cm long.

We've gained some more altitude, but we're still at the toe (bottom) of the reef's massive slope. The tilt of the beds you see here is not indicative of the photographer's lack of balance or poor perception of the vertical. Reef-slope strata like this form at a tilt, either steep or shallow, depending on their exact location. In this case, we're probably looking at what, as the Guide suggests, are turbidites deposited by low-density submarine avalanches.

If I'm correct about this outcrop being at or very near the one described for Stop 2 in the Guide, this thin-bedded to laminated unit is wackestone. This arcane term comes from the Dunham classification system widely used by sedimentary petrologists.

Wackestone is a type of carbonate rock that is mud-supported (has a matrix consisting of microscopic, mud-sized particles) but also has larger grains that make up at least ten percent of the rock.

Also in this vicinity are examples of packstone, which has less mud and enough larger particles for it to be "grain supported" instead. Both of these types here belong to the Lamar Limestone Member of the Permian-period Bell Canyon Formation.

The Dunham scheme also contains other categories I need not discuss in this essay. But I would like to add two more of my own.

The first, yakstone, is a carbonate rock that you carefully scrutinized a number of years ago, but whose exact composition you cannot now completely remember. Nevertheless, you yak on about it, saying whatever can be said up to the limit of your knowledge. The rock shown above, while probably also a wackestone, definitely qualifies as yakstone.

Much more insidious is quackstone, a type of carbonate rock that is talked about circumlocutionally and not at all understood by an intellectually lazy person who is, it must be said, a quack.

One example of a quack is a person who talks in an authoritative tone about this locale's lithology having never actually walked the Permian Reef Geology Trail while keeping one eye assiduously glued to his print copy of the Guide. So the rock shown above is obviously not quackstone.

Incidentally, if you're wondering what the plants in this shot are, they're Smooth Sotol (Dasylirion leiophyllum, below) and Ocotillo (Fouquieria splendens, above). They'll be more prominently featured later in this series.

You'll find the other photos and descriptions of this series in my Moseying Up the Permian Reef Geology Trail album.

Heading back towards the rental after taking pics of Guadalupe Peak.

Guadalupe Peak is the highest natural point in Texas, with an elevation of 8,751 feet (2,667 m) above sea level. It is located in Guadalupe Mountains National Park.

Texas brown tarantula ( Aphonopelma hentzi) in Guadalupe Mountains National Park