Category: Geology

In New Mexico we are accustomed to hiking in landscapes that can be described as “moonscapes.” Today’s desolate hiking destination took us through an otherworldly landscape around a special type of volcanic crater known as a “maar”,  hence a “maars scape.”  When hot, molten rock comes into contact with subsurface water it can cause a huge explosion of steam that hurls ash and volcanic material over a large area before collapsing and creating a shallow crater.

Kilbourne Hole, located about 25 miles southwest of Las Cruces, is a large maar designated a National Natural Landmark in 1975 due to its unique geology.  We are spending a couple of days exploring hikes in the Las Cruces area and decided that today would be a good day to check out this special volcanic feature.

I thought a feature designated a national landmark would be fairly accessible, but without the detailed driving directions in our guidebook “Day Hikes in the Las Cruces Area”, we never would have found it.   There’s no such thing as a direct route through this part of Dona Ana County.  Once leaving the interstate, it is a series of 8 different turns back and forth on increasingly rough county roads leading out into the vast Chihuahuan Desert grasslands.  The only sign indicating that we were headed towards Kilbourne Hole was a hand written sign placed on one of the dirt roads that branched in two directions.  My guess is that the rancher got tired of having lost tourists taking the wrong branch and ending up at his ranch.

The edge of the crater itself is the only indication that you have finally arrived at your destination. The bottom of the crater is private land but a number of jeep trails and dirt roads surround the rim, making it possible to hike the entire 7-mile perimeter. Except for some sandy areas that made for difficult walking, it is not a strenuous hike. It’s not exactly a scenic hike, but it does have the desolate beauty of the desert solitude we enjoy so often in the Land of Enchantment.

Besides being a volcanic maar, Kilbourne Hole is renowned among rockhounds as a place to find “volcanic bombs” or xenoliths. These are blobs of molten lava ejected from the volcano that contain pieces of other rocks, most notably olivine crystals in the hardened lava rocks at this location. We found many broken pieces of black basalt that were encrusted with the bright green olivine crystals.

Bright green anything is a welcome sight this time of year.  Lee found a couple of tiny flowers that he could photograph but not much else was growing yet.  Thankfully, the spring winds aren’t blowing yet either.  After a chilly start in the morning we had plenty of sunshine to warm us up and make a perfect hiking day.

After viewing hundreds of photos last night from Mike Richie’s “San Juan Basin Badlands” presentation at the Native Plant Society meeting, it was obvious that today’s hike should be an exploration of one of the areas discussed in the presentation. Shortly after moving to Albuquerque, I went on a hike with the hiking club to Ceja Pelon, one of the 5 Nacimiento Badlands west of Cuba. Lee and I have considered exploring out there before on our own but without any established trails we didn’t know if we should attempt it.

Just recently, however, I discovered a phone app that allows me to load a GPX track on to a map and then follow the track–exactly the functionality that a handheld GPS device provides but no need for an extra gadget. The hiking club publishes their GPX tracks on their website so now we can use their tracks to guide us to new destinations.

For today’s hike we selected Mesa Penistaja, a 6.6-mile loop hike that promised interesting rock formations and lots of petrified wood. It certainly delivered on the petrified wood. Pieces of all shapes, sizes and colors were scattered throughout the arroyos and on top of the hillsides. The dominant flower in the grassy areas was the Mariposa Lily. I have never seen them in such abundance. Many were growing together in clusters, whereas usually they are just a single isolated plant.

The GPX track gave us a place to start the hike and a reassurance that we could find our way back through the maze of arroyos. We ended up only doing about half of the published hike before we veered off and created our own track. With so many things to look at we weren’t hiking very fast and, given how hot it was, we felt that 5 miles was enough to call it a day.