On our trip (of which only 1/3 of participants was a geologist) we were able to make a quick stop at the El Malpais National Monument. This area is renown for it’s rich volcanic terrain and as a studying geologist that’s interested in volcanology and potentially will be visiting the area again this Fall in an expanded capacity, I was really excited to check some stuff out. Our time was limited, so after stopping by the visitor center we decided on a short little hike that would let us see some lava tubes and a volcano.
The area we decided upon, at the ranger we spoke too’s suggestion, was El Calderon. El Calderon is a cinder cone volcano that was formed around 115,000 years ago from lava fountain style eruptions. Sometime after the fountaining stopped, the eruptions continued in the form of fast moving basalt flows that carpet a wide area in the vicinity today. This period of basalt flows leaves a jagged terrain of vesiculated rocks, but more interestingly to me, a geology enthusiast from the flatlands of Illinois, it left behind the tubes by which that lava flowed all those years ago.
You can see on the poster above (maybe) that these tubes are now closed off to the public to protect the bat poulations from the threat of White nose syndrome. Fortunately for us, there are smaller, partially collapsed lava tubes available to traverse on the El Calderon trail, and traverse it we did.
It’s really dark inside the tubes, so these were the only images I was able to grab, but it was a really cool experience. I wish we had the time and permission to go further into them. The lava tubes, when they’re open to the public, are pitch black, trail-less caves to explore.
This is a sample of what all the rock in the above images is like… It’s very sharp, jagged, highly vesiculated basalt. It’s not kind on the body when you miss a step and trip or need to catch yourself when slipping.
Vesiculation (formation of gas bubbles; and thus the holes in the above image) occurs under several conditions; increase in temperature of the lava, for example when there is an influx of newer, hotter magma; increase in the concentration of volitailes (CO2, SO2, etc.) usually by the crystallization of anhydrous (water-phobic) minerals; or a decrease in pressure caused by the ascent of the magma/lava. In the case of El Calderon, the lava flows were apparently very fast and moved long distances quickly so I think it’s case of the latter, where the lava quickly made it’s way to the surface and became highly vesiculated in the process. I also could be way off, I have almost zero background information beyond a few brief web pages.
After we exited the lava tubes, we made our way to El Calderon itself with every intent to get to the crater. Teejay is doing some sort of crip-walk or something here apparently.
Unfortunately, shortly before reaching the base of the volcano, there was a fence, a gate and a Private Property sign. That seemed odd, so we think we took a wrong turn somewhere, and in the interest of time, we had to turn around and head back to our car.
The whole experience made me really excited to head back there sometime though. I would love to spend some time in the field there and observe many of the phenomenon that I’ve only read about and seen in picture.
ALSO: Nearby is the Bandera Volcano and Ice Caverns and their website said they opened at 8am, so we showed up at 8am. When we got there the sign said they opened at 9am. FUCK EM. We went here instead after that (The other place still sounds super awesome though, so fuck em in the sense like “Damn! I really wanted to go!” not “Fuck those shitty assholes.”).