The Mineral Maketh the Monument

I spent my holiday weekend exploring New Mexico and Arizona. I visited four national park service sites. I played in the sand, hiked amongst stone columns, walked through fields of trees turned to sparkling stones, and looked from a volcanic plateau over a desert of color. I visited White Sands National Monument, Chiricahua National Monument, Saguaro National Park, and Petrified Forest National Park, and with the exception of Saguaro, I was struck by how little flukes of crystallography and geology birthed the places of beauty I admired.

White Sands National Monument

White Sands National Monument is located in southeast New Mexico, not too far from Roswell. The national monument is surrounded by White Sands Missile Range, which contains the Trinity Site (which by the way, looks rather dull from the road, just a plaque. There were a lot of cattle grazing nearby, amusingly). Occasionally, the monument closes because of tests on the missile range. The morning of the day we visited, an F-16 crashed in the missile range (the pilot was okay).

White Sands National Monument is made up of gypsum sand. That sand is actually why it’s a missile range. It’s brilliantly white, and thus makes a great target. Check it out on google earth, it really sticks out.

Gypsum is water soluble, so gypsum dunes are pretty rare. The White Sands dunes exist because the Tularosa Basin in which it sits has no drain. The dunes are basically a dried lake bed–a small lake does exist at the southern end of the park. In my humble opinion, gypsum kicks silica’s (normal sand) butt. The grains are very fine. They sell sleds in the gift shop, and families went sledding on the dunes. The sand doesn’t capture heat like silica sand does. And when you get sand in your mouth, as you will when sledding or when you drop your water bottle in  the sand like I did, it dissolves. Truly, the gypsum sand dunes are the closest thing I’ve ever seen to warm snow.

(Gypsum is generally just a cool mineral. Selenite is composed of gypsum. If you’re in a rock shop, find a piece to look at. Selenite has what is known as birefringence–if you set it on text and look through it, you’ll see that text twice. Gypsum also is what desert roses are made of. Selenite crystals have been found up to meters long in caves in Mexico. Gypsum is also what makes drywall. And gypsum is just calcium bonded to sulfate. Chemistry is wonderful stuff.)

The White Sands National Monument is spectacular, more spectacular than many national parks I’ve seen. The nearby Organ Mountains are beautiful too. I suspect this would be a national park, if not for the air force wanting to bomb it from time to time. It is absolutely worth a visit– but it is in southern New Mexico, so perhaps at a cooler time of day or year. On November 25th, it was a high of 75, and it was great.


Chiricahua National Monument

Chiricahua National Monument is the 14th least-visited national monument of the 114 national monuments in the country. I thought it was paradise. There aren’t many places this beautiful that you can enjoy in relative privacy. Unlike many of the little-visited national monuments in New Mexico, Chiricahua has quality paved roads all the way to and into the park. It’s only a 40 minute drive from I-10 in southeastern Arizona. If you happen to find yourself in that part of the country, Chiricahua is worth it.

The magic mineral in Chiricahua is volcanic rhyolite. Rhyolite is chemically similar to granite, but it forms differently. It cools faster at the time of formation, and therefore has smaller crystals. The rhyolite at Chiricahua formed with tension in the rock, leading to cracks called joints. Over millions of years, wind, water and plant life have worked at those cracks and led to the thousands of rhyolite pillars that fill the park. Much of the work was done in the CCC era… walking around I marveled at what hard work that much have been in this park, and yet 80 years later the park is still relatively unknown.

Chiricahua has been one of my favorite hikes yet. We did the Echo Canyon loop trail, which is chock full of great sights. You see columns up close and at a distance, with relatively little pain for a 3.3 mile trail. Several other longer trails looked like fun, and I intend to be back to check them out.


Petrified Forest National Park

Although this was the most famous of my destinations, the miner0logy for this one was the toughest to research! Petrified Forest National Park contains its eponymous petrified wood, but it’s also famous for the colorful sands of the painted desert. I found lots of information on petrified wood; it is formed by felled trees that, because they get buried for some reason, are not subject to the normal decay processes. The wood turns to agate (like those agate slices from geodes that I used to collect as a kid) and the result is beautiful colors and stone. Some of the wood is imperfectly agatized, and still contains ancient DNA, which is also cool. It’s pretty cool to think that the grassland desert of Petrified Forest was once an equatorial forest full of enormous trees. What a difference 200 million years makes!

The painted desert was harder to research. The different colors are due to different layers of rock from different eras. But I wanted to know why some were blue or red or purple or yellow! What chemicals? The internet is built by geeks of the bit variety and less the atom variety, so my struggle turned up little in the initial investigation. So, I take it as a great challenge for a future post!

Petrified Forest was a bit cold this time of year! The low overnight when we were there was 22. So I must recommend it with a tad more warmth. But the hiking was great. We did a backwoods trail by the Jasper Forest and walked along the dirt road that once brought stage coaches from the railroad station. If such a landscape feels alien to us, with TV and internet bringing us HD video of any place at a click, one thinks what a landscape felt like in 1906 when the park was designated as a national monument. Even today, it’s an open, austere place, full of ruins 200 million years old.



1 thought on “The Mineral Maketh the Monument

  1. Rhonda Fleming

    Great photos, Karen! I’m adding these spots to my list–I’ve been to White Sands several times, but it’s always new every time I go there!



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