Thursday,
March 15 – Carlsbad Caverns
David “Skeeter” Vandermast
(& Rob McDonald)
After a shower and a restful night we gathered in the parking lot of our motel, The Bien Venido, for a breakfast of coffee and bagels, and one last hack, before heading off to Guadalupe Mountains National Park. I drove the green van, temporarily named “Skeeter Peter and the Fair Maidens” after it’s transient inhabitants of the previous day: yours truly, Laura, Michelle, Becky, Andrea, and Jessica. Although there was some disagreement over the prerequisites for being a maiden, and whether any my companions could therefore be considered maidens, the name was catchy and it stuck.
For our journey on this fine day we were joined by our indefatigable Supreme Commander, but had to sacrifice fair maidens Andrea and Becky. As lead van in the convoy we enjoyed being in front whilst the other vans had to suffer eating our dust as we had been eating theirs earlier in the week. Had we actually been on a dirt road our revenge would have been sweeter. As it was we headed west on Rte 90, through Marfa, home of the unexplained desert lights, to Van Horn, where we caught Rte 54 north to the park. Along the way we were greeted with the sight of a large, white blimp-like object that could be seen miles before it was reached. It turned out to be part of an Airforce base that was subtly situated on the plain upon which we traveled. It may be some kind of covert government operation involved in FBI Agent Fox Mulder’s disappearance; we’ll have to ask Laura to investigate.
Not all organisms of interest to us were plants. On the way to Guadalupe we saw antelope and a roadrunner that had a near-death experience with the lead van. During our time in west Texas we also saw mule deer, peccary and at least two species of lizard, including the one Dane, er…Dale, stepped on. Personally, I was disappointed we didn’t see any snakes. I really want to see a Gila Monster too some day. Gila Monsters are found in the Sonoran Desert, a place I believe our lab group has never been (hint, hint).
Just south of Van Horn we also happened past the aforementioned Pecan plantation. Rows and rows of Carya illinoiense spread to the horizon on our right. Pooled irrigation water evaporated in the morning sun. Not one of the ecologists in our caravan could figure out why a Pecan plantation should be grown in the desert. The pessimists among us (ok, me) decided that the grower must have a nice government subsidy to cover the cost of drawing all that irrigation water from somewhere. Or, it could have something to do with that secret Airforce base…hmmmm. Other vegetation, more characteristic of the Chihuahuan Desert was also spotted along the road: Juniperus monosperma/coahuilensis and Yucca elata.
North of Van Horn the highway is pretty darn straight and yet the speed limit is only 55 mph. We, however, cruised Guadalupe-ward at a speed slightly higher than that. For most of the trip along Rte 54 we were in a broad valley; the road frequently crossed arroyos, but it did not follow the bottom of the valley. In keeping with the appearance of paradoxical phenomena, official-looking flood-level signs had been placed above the road at an elevation seemingly far higher than water could ever be expected to reach. Had the signs been old we might have concluded they were left over from pre-biblical flood times. But they were relatively new and shiny. Is it possible west Texas was simply being pro-active about global climate change?
As we neared the park we could see 8,749 foot Guadalupe Peak looming before us. Off to our right a row of wind turbines had been erected on a ridge. Dane happily reported to us over the CB that wind power is a sustainable energy source, especially in west Texas where it is almost always windy. In yet another irony befitting the desert, we were in west Texas oil country, in the home state of our President (an oil guy from way back) who claims he does not believe in global warming, yet we saw proactively placed flood signs and sustainable energy sources. Go figure.
Guadalupe Mountains National Park was established by an Act of Congress in 1972, but the geologic forces that created the topography we were seeing occurred long ago. Roughly 260 million years ago a shallow sea covered west Texas and southeastern New Mexico. As often happens in shallow seas, reef organisms flourished, taking calcium and carbonate from seawater for their exoskeletons. After they died their shells were crushed into powder by waves and rocks; the resulting sediment was cemented with additional calcium carbonate. Over millions of years this process formed a thick limestone reef. The limestone deposits that formed the Guadalupe Mountains and now hold Carlsbad Caverns are known as the Capitan Reef. Twenty million years ago tectonic forces pushed the reef upwards, forming the Guadalupe Mountains. Softer sediments on top of the reef eroded, leaving behind the more resistant limestone. Most of the reef remains underground; only the Guadalupe Mountains, Apache Mountains north of Van Horn, TX, and Glass Mountains east of Alpine, TX are exposed.
Location: N31º45.30’ W104º59.05’ [Map]
Elevation: 3641 feet
[Photo - Allenrolfea in the salt basin]
Where TX route 54 intersects with US routes180 and 60 we turned left and drove roughly five miles west to the Tularosa Salt Basin. The basin was created as the prehistoric Delaware and Comanchean Seas evaporated, leaving behind a playa with soils containing high concentrations of minerals and salts. Speaking from personal experience, the soil really does taste salty. Salt deposition on dry lakebeds is not uniform; salt concentrations increase from the margin to the center of the flat. In addition, upper surface soils have higher salt concentrations than subsurface soils. Halophytic plants may maintain osmolarity with their environment by accumulating cations or anions in their cells. Other plants may secrete salts (e.g. Tamarix) or story them in bladder-like trichomes (e.g. Atriplex) to avoid high intracellular salt concentrations. Turgor can be maintained against osmotic gradients through the use of non-metabolic negative pressure gradients.
Guadalupe Mountains National Park is home to more than 1500 species of plants but as one might expect (assuming one is an ecologist), plant diversity in the salt flats was pretty low. Representative native plants included and were pretty much limited to:
Allenrolfea occidentalis Atriplex canescens
Sporobulus aeroides
Our old friend from the riparian areas in Big Bend, the phreatophyte salt cedar (Tamarix sp, probably ramosissima) was also in evidence near the road. Looking at the distribution of plants out on the flat it was not hard to envision that, in this water-limited environment, seedlings germinate and grow under existing plants. Almost all plants grew in close association with other plants, forming sinuous lines of vegetation on the playa.
We also visited an adjacent sand dune (N31º45.32’ W104º58.77’; elevation 3661’) and noted:
Yucca elata Atriplex canescens
After departing the salt flats we hastened to the park campground to obtain the appropriate number of tent pads. We reserved our spots by erecting several tents and drove northeast to Carlsbad Caverns National Park. Our purpose there was twofold: see the cavern and sample desert scrub.
15-2 Hypogean habitats and cavernicolous creatures
[Map]
Upon arriving at Carlsbad Caverns we ate lunch and obtained tickets to the cavern (including a guided tour of King’s Palace). Before entering the cave we watched a short mandatory video on the creation of the cavern and its initial exploration. In addition to biological processes that deposited the limestone and geological processes that lifted the reef to form the Guadalupe Mountains, chemical processes were responsible for the formation of the cavern.
As the reef was pushed-up by tectonic forces it cracked and fissured allowing fresh water to flow into the cracks. At depth, the water mixed with hydrogen sulfide gas from petroleum bearing rocks and formed sulfuric acid that ate away at the limestone reef. Hydrogen sulfide reacted with the limestone, eating away at it and leaving the beginnings of the caverns we see today. During this process the caverns were filled with water; formation of characteristic cavern structures did not begin until the water receded.
As the climate dried and less water made its way into the cavern, portions of the cavern no longer supported by water fell to the cavern floor. Lesser volumes of water continued to flow into the cavern and used calcite, deposited as the groundwater receded, to create the cave formations seen today. Water from the surface carried concentrations of organic acids that further eroded the limestone reef and caused the water to pick up calcite on its way to the cavern.
Formations such as the popcorn we saw on cave walls are thought to form as water evaporated leaving calcite behind. Spaghetti-like structures called helictites formed when water was hydrostatically forced through small pores in the limestone. Stalagmites (ground up) and stalagtites (ceiling down) formed as calcite rich water dripped through limestone pores into the cavern. Draperies are sinuous, curtain-like structures that grew as water flowed down the cavern ceiling leaving deposits of calcite behind during its journey.
Airflow through the cavern helped create unusually shaped structures that were clearly not the work of gravity alone. During the millions of years cavern structures were being created glaciers ebbed and flowed; rainfall above the cave and humidity within it caused alternating periods of rapid structure development with periods of little activity. Milky looking structures formed during times of low precipitation when the water that reached the cave was highly concentrated with calcite. During wetter periods water reaching the cave was more dilute and the resulting structures appear glossy. Structures in the cave would all be off-white but for water traveling to the cavern from above carrying minerals that give some structures additional color. Manganese gives formations a black hue, red comes from iron, orange and brown are caused by organic acids.
The cavern was used by native Americans prior to European occupancy of the area. Around the turn of the 20th century the main entrance to the cavern was first explored by a cowboy named Jim White. The story told on the video was that White had been looking for lost cattle when he noticed a stream of what he though was smoke coming from somewhere over the horizon. As he approached the source of the smoke he noticed it wasn’t smoke at all but countless bats streaming from the mouth of the cave. Other sources report that the location of the mouth of the cavern had been known for years; White was simply the first to use it to explore the cave.
After the introductory video we began our 800-foot descent into the cavern. The paved path allows nearly anyone to make it into the cavern but detracts from what would otherwise be an exceptional experience. Still, the cavern itself is marvelous and worth experiencing in person. At the end of our descent we turned right into the Big Room, or as we euphemistically named it, the “Room of Phalluses”. Jason reasoned that there are few operable shapes in nature and consequently, they are repeated over and over. Jessica was speechless! I took the spiritual approach: we were in the subterranean source of the libido of all mankind.
We finished touring the Big Room in time for about a half-hour of hack near the underground concession stand before our guided tour of King’s Palace began. Before the tour began we were herded into a staging area with roughly 50 other people and had a chance to ask the tour guide questions. While our fellow explorers asked predictable questions, our socially conscious crowd, led by our token anarchist, Dane, wanted to know how the Park Service justified having a subterranean concession stand when they wouldn’t allow people to bring their own food. Perhaps he was miffed at the minimal vegan fare they offered.
While King’s Palace itself was extraordinary, the guide was only interesting if you were willing to experience the place at a superficial level. One salient fact: King’s Palace was closed except for guided tours because over the years an estimated 30,000 stalagtites had been stolen from one of the rooms.
After the tour we crowded into elevators for the trip to the visitors center, our original starting point. We packed back into our vans and on the way out of the park, stopped once to botanize on the mesa.
Location: N32º10.88’ W104º26.01’ [Map]
Elevation: 4219’
Berberis thunbergii Opuntia imbricata
Notholaena sinuata Muhlenbergia
sp.
Anemone heterophylla Agave
lechuguilla
Juniperus monosperma Opuntia
engelmannii
Selaginella sp. Dasylirion
wheeleri
Fouqueria splendens Aristida
sp.
Bouteloua curtipendula Echinocereus
reichmanii
Opuntia rufida Nolina
micrantha
Yucca torreyana Gymnosperma
sp.
Lycurus phleoides Stenandrium
barbatum
Echinocereus triglochidiatus Echinocereus
leptocaulis
Coryphantha albacolumaria
Concluding
remarks …
At the entrance to the park we stopped for supplies. At this time we learned that Dane likes salty peanuts. This comment is funnier when you realize that “peanuts” said quickly enough sounds like a part of the male anatomy. Michelle used this mispronunciation to get Dane to admit he liked his salty peanuts in any way, shape, or form. It was a great laugh for those of us in the know.
We retreated to our Guadalupe Mountains campsite and ate a TVP-based chili dinner washed down with cold Corona. The ensuing night was very chilly, probably dropping into the 20’s (Fahrenheit, that is). Several of us walked several hundred meters away from camp and gawked at what surely must be one of the most amazing displays of stars anywhere. During this short expedition I discovered that fleece clothing does nothing to keep you warm when it’s windy.
We eventually retreated to the campsite where most of us realized we would be warmer if we were to climb into our sleeping bags. The night was cold enough that many of us chose to endure a full bladder rather than exit our relatively warm sleeping bags for a bathroom trip. Because Guadalupe is just inside the Mountain Time Zone, we woke early and ate breakfast. Many of us were cold during the night and it was still quite cold during breakfast before the sun rose fully. Consequently when our Supreme Commander asked if we wanted to leave for home that evening or spend another night, we almost unanimously voted to leave early.
We left at 8:00 for a short stop at the Visitors Center followed by a day of hiking and botanizing in McKittrick Canyon.
References:
Brand, A.P. and A.D. Jacka. 1979. Geology of the Guadalupe Mountains National Park. In: H.G. Genoways and R. J. Baker, eds. Biological Investigations in the Guadalupe Mountains National Park, Texas. National Park Service Proceedings and Transactions Series Number Four.
Burgess, T.L. and D.K. Northington. 1977. Desert Vegetation in the Guadalupe Mountains Region. In: R.H. Wauer and D.H. Riskind, eds. Transactions of the Symposium on the Biological Resources of the Chihuahuan Desert Region. National Park Service Transactions and Proceedings Series Number Three.
Crane, C. 2000. Carlsbad Caverns National Park: Worlds of Wonder. Carlsbad Caverns Guadalupe Mountains Association, Carlsbad, N.M.
Henrickson, J. 1977. Saline Habitats and Halophytic Vegetation of the Chihuahuan Desert Region. In: R.H. Wauer and D.H. Riskind, eds. Transactions of the Symposium on the Biological Resources of the Chihuahuan Desert Region. National Park Service Transactions and Proceedings Series Number Three
Northington, D.K. and T.L. Burgess. 1979. Summary of the Vegetative Zones of the Guadalupe National Park, Texas. In: H.G. Genoways and R. J. Baker, eds. Biological Investigations in the Guadalupe Mountains National Park, Texas. National Park Service Proceedings and Transactions Series Number Four.
U.S. Park Service. Guadalupe Mountains National Park website: http://www.nps.gov/gumo/