Some History: Geology and Photography

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I was digging through my now gargantuan Lightroom library the other day. It houses over 80,000 RAW images. Almost 50,000 of them are birds, another 8000 are wildlife, and nearly 5000 are astrophotography. I have another 3000-4000 each in landscape and macro photography. While digging around, I came across an old buried folder that had my first photographs ever, taken with my original Canon 450D (Rebel XSi). I had actually originally purchased the 450D in 2009 for a large trip I had planned with my parents, we were going to visit most of our north central monuments and national parks…Mount Rushmore, Devil’s Tower (a favorite landmark of mine from my childhood, from when I first watched Close Encounters of the Third Kind…still one of my favorite movies today!), as well as Yellowstone and Grand Teton National Parks.

Garnet-encrusted ceiling in Wind Cave.

Garnet-encrusted ceiling in Wind Cave.

Some of my first 100 photos came from the caves around Mount Rushmore, Wind Cave and Jewel Cave, which are in Custer State Park. I had practically no experience with a camera, no experience with flash…and my first photos ever? Yup. They were taken in the near bitch dark of a cave, deep underground. As it turned out, those photos actually ended up being pretty good. Another staple of my childhood was visiting caves…on just about every family vacation we took in California once I was old enough, my parents would take my brothers and I into one cave system or another. They were all amazing, especially when you enter a cave where they dim all the lights, then pulse a couple flashes onto a region of stalactites and stalagmites that exhibit photoexcitation and fluorescence, resulting in a residual glow that persists for several seconds in the pitch dark. So, perhaps it is somewhat appropriate that a cave was one of my very first photographic subjects.

Boxite, a calcite remnant of a unique cave formation.

Boxite, a calcite remnant of a unique cave formation.

Wind Cave was the first cave we visited. Wind cave is huge, it completely covers an area of one square mile, reaching down to depths as deep as several hundred feet. Additional exploration has found arms of the cave that reach beyond the one square mile area, and there are countless unexplored squeezes that could ultimately lead to caverns and passages that extend for many square miles. The tour we took demonstrated one of Wind cave’s more unique features: Boxite. This calcite formation reached into cracks in sandstone, which was later weathered away during a submersion stage of the cave. That left boxite behind, the thin waxy-looking plates as pictured above. Another interesting facet of Wind cave is the fact that it has one single natural entrance. That results in an interesting pressure dynamic, where external pressure results in wind rushing into the cave system through this one small hole, and where external pressure drops result in wind rushing out of the cave system through the same hold. Hence the namesake.

Jewel encrusted walls with the flowing beginnings of curtains forming around them.

Jewel encrusted walls with the flowing beginnings of curtains forming around them.

Jewel Cave was the second cave we visited. Jewel Cave, while smaller in extent, was more beautiful. Wind cave had a rather monotonous appearance, boxite everywhere, brown and brown and brown. No stalactites or stalagmites. Jewel Cave, on the other hand, truly lived up to it’s name: The walls, many tens of thousands of square feet worth, were literally covered in jewels. Dogs Tooth was the most common, sometimes bare and clear crystal, most often frosted. Other crystals were present as well, and in some places stalactites, stalagmites, columns, small “straws”, and curtains flowed over the jeweled cave walls. One intriguing feature, pictured below, is called “Cave Bacon”…a beautiful formation especially when backlit.

The unique formation, "Cave Bacon", found in Jewel Cave.

The unique formation, “Cave Bacon”, found in Jewel Cave.

Jewel Cave had one room in particular that contained the bulk of it’s interesting formations. This cavern was by no means as large and majestic as some, such as Carlsbad, however the jewel encrusted walls really gave it a unique appearance. The one pictured below was a very small, thin, but tall column that stretched between an indentation in a Dog’s Tooth encrusted wall:

Tall, thin Cave Straw stretching in front of a Dog's Tooth wall.

Tall, thin Cave Straw stretching in front of a Dog’s Tooth wall.

Shortly down the passage past the great hall of Jewel Cave was one of the few stalagmites, the large lumpy formations that form on cave floors thanks to stalactites that drip overhead. This particular stalagmite was also surrounded by jewel-encrusted walls, which themselves were home to a slow flow of formations cascading down the walls and around this lone stalagmite.

A rare Jewel Cave stalagmite, full of earthy color, surrounded by Dog's Tooth walls and a flow of formations.

A rare Jewel Cave stalagmite, full of earthy color, surrounded by Dog’s Tooth walls and a flow of formations.

If you ever get up to the Dakotas, check out Custer State Park and Jewel and Wind caves. Beautiful sights, all of them. Custer is full of wildlife, including large herds of bison. And the caves are infinitely complex.