Guadalupe NP

INTRODUCTION

(with two photos added in January of 2014)

My cardiologist, upon hearing I was heading for New Mexico, recommended I read West of Babylon, by Eduardo Garrigues (translated by Nasario Garcia, Univ. of New Mexico Press, 2002) and get a rather unique perspective on the countryside I would be seeing.

I started to read the book, and by the time I landed in El Paso had gotten to the page that mentioned a Dog Canyon in a mountain range where there was a dense forest on the top of the mountain and a stark desert below (page 87). I realized the story took place in the north-central part of the state. The Dog Canyon mentioned was the headwater of the Ruidoso River, not far from Cloudcroft and a bit out of reach for a short visit to Carlsbad via the El Paso airport.

But, reason is easily cast aside.  On the drive up from El Paso I stopped at the Guadalupe Mountains National Park visitors center where I saw a description of a forest at the top of the beautiful ridge I was looking at from below, and there was a Dog Canyon on the north end of the park just 12 miles from the visitors' center (but about a hundred miles by car).  OK!  I knew it was not the same Dog Canyon, nevertheless I determined to spend my last hours of daylight in this Dog Canyon.

Two days later, on the way back to the airport in El Paso, I took a short walk into yet another canyon, McKittrick Canyon.

CANYONS INTO WHAT?

Unless you are familiar with this area, you may be asking the question posed above.

These two canyons are cut into a high ridge that runs roughly southwest to northeast, at least here.  It is part of a huge horseshoe-shaped formation that at one time was a reef around a sea that existed here from 260-270 million years ago, approximately. The point is that the reef had millions of years to build up, and as it built up the sea floor sank, and it just kept growing, staying just below the surface, just like a modern coral reef.

2014 photo addition: On 20 December 2013 a rain event caused there to be runoff from the Guadalupe Mountains into this dry lake. Here is what it looked like 15 days later.  This water is gypsum- saturated and will leave behind a nice clean gypsum layer as it evaporates.

End of 2014 photo insert.

But this was not a modern coral reef. It was a similar idea though. The bodies of dead sea-animals, like sponges and other species that had some carbonate as a component of its bodies, donated their dead bodies back to the sea and added to the calcium carbonate that was precipitating from the water onto the sea bottom toward the shore, in the shallower water where evaporation caused just a minor enhancement in concentration allowing it to drop carbonate from solution, to precipitate calcium carbonate, and make a calcite sediment which, when it got thicker and buried, was compressed into limestone rock.

So, picture a wide calcite deposit well below the sea surface, like a very wide ribbon around the sea’s edge. Miles, apparently, into this sizable sea there is a zone particularly well stocked with sea creatures and there not only do their dead bodies contribute to the carbonate levels in the water, they are also so plentiful as to accumulate and add directly to the calcite of the sea bottom, making a ridge that rises continually.  As it rises, the ever heavier sea-bottom is sinking of its own weight-gain (I know the feeling!) and the ridge always stays deep enough beneath the water’s surface to allow animals and plants to live and die on its top.  

The ridge also grew some toward the open sea, away from land, and as it grew toward the deeper part of the sea it did not have good support from the slope below it and pieces would at times break off and slide down the deepening slope toward the central part of the sea. This means, walking out from land, there was carbonate being deposited on the sea floor, along a layer that was miles wide, an area now called the 'backreef.'

Then came the reef itself, sticking up out of the depths until it came quite near the water surface.

Finally from there out into the deeper sea there were chunks of broken-off reef that had become tilted, and some pieces had slid toward the deeper part of the sea’s floor. This forward-sloping limestone is now called the 'forereef.'

At some point in time the sea was cut off from its open-ocean source and eventually it dried up, leaving in some areas of its former depths horizontal layers of salt, occasionally overrun with layers of silt and clay when there were floods from the surrounding highlands. Eventually the whole sea bottom, salt beds, forereefs, backreefs, and the reef itself, all became covered by sediments washed from the surrounding higher land.

Today the reef’s arc is still buried by sediment in some places, and raised high above the desert floor in others. As the arc ranges toward the northeast it gets lower and lower and is hidden under sediment for much of its arc. Near Carlsbad there are magnificent caverns dissolved by water into this very same reef formation. If you want to see my photos of these caverns, just click here.

As the arc turns south again once past Carlsbad, it stays underground until it resurfaces as the Glass Mountains in Texas. Straight south of the national park it is submerged under sediment and trends toward the southeast.  It emerges once more as the Apache Mountains in Texas.  The main part of Guadalupe Mountains National park lies in Texas, but the New Mexico border cuts across the range.

This diagram illustrates the shape of the reef and its raised portions.


Click here to go to the website from which I took this illustration.  It has a wealth of information in it and is very well put together.  In only one tiny place does it make a little boo-boo, and that is where it seems to quote someone who says a tree found in this canyon is a "rainforest relict" when, as it says elsewhere on the same site, it is an ice age relict.  The last rainforest here may have been at the time of the dinosaurs, the last ice age was just 10,000 years ago, give or take.

The mountain-building episode is the same one that led to the formation of the Rocky Mountains about 12 million years ago.  The former sea bottom and its raised edges were elevated compared to where they were before. The formerly overlying sediments were eroded downhill by rains and by snow-melts, filling in what used to be the deeper areas of the sea, covering the beds of salt with more and more sediment. That sediment kept coming downhill until the harder limestone of the reefs was exposed, slowing the erosion there to allow the eventual formation of what looks like a large mountain range under a ridge of limestone, carbonate rock, that resists erosion more than the softer sediments do.

The end result is what you see here now: limestone ridges high above sediments that surround and grade down to the bottom-lands far below. What used to be sea-edge-bottom is now a high mountain range!

Over the last few millions of years this area has been quite stable, meaning the continued wearing-down of the reefs is progressing at a slow rate. There is no hurry to get here and see it all for yourself.  Relax. Change over a single human lifetime will be quite largely unobservable except in specific places where a single storm might do erosive damage and cover a road or trail with debris from the higher places or temporarily dam a stream.

What has happened over the last million or so years is continued changes in climate, with the climate being cooler and wetter about 80% of time over the last million years.

The last cooler and wetter time period was an ice age, without any ice here, but doubling annual precipitation and cooling off the summers some ten degrees, likely. The last one of these cooler and wetter periods ended only 10,000 years ago (approximately). During the 20,000 years of cooler and wetter weather preceding this current hot and dry period, vegetation became established on these mountains that could not have become established during the current climate, even though it can persist into this climate.

Two instances stand out among the examples of species established during wetter, cooler times but still able to survive the current climate in selected places.

On the highest ridge line is a large area where soil, slope, and precipitation allows the continuance of a large stand of pines, including Ponderosa pines. Where these trees thrive still is called “the bowl” for a good reason, and the bowl shape has created locally favorable conditions for tree growth in terms of soil depth, moisture retention and a relatively cool micro-climate. This pine forest is called a "relict" forest. It can survive where it now is, but it cannot expand in the current climate.

One of my many life goals now is to climb up to where this pine-forest is.  I did not get to do so this time, but I did see the forest from a distance on my Dog Canyon walk, linked below.

There is a real eye-catching tree called the madrone, or locally the Texas madrone.  It is also a relict species established during the last ice age and now surviving only in more protected portions of the wetter of the canyons, McKittrick Canyon.

The tree is illustrated in the McKittrick Canyon pages linked below.

So now we are ready to talk about the two canyons I briefly visited, and the links below will take you there.

What about the book I started out reading?   West of Babylon, by Eduardo Garrigues? I read nights during this trip and finished it the day after, and thoroughly enjoyed it.  It is fiction, fantasy.  It melds together two mythological traditions from opposite sides of the world and makes them into an adventure worth reading into the night for several nights, as I did.

McKITTRICK CANYON (1)

McKITTRICK CANYON (2)

DOG CANYON (1)

DOG CANYON (2)

DOG CANYON (3)

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