|Entrada Sandstone Fins at Fiery Furnace, Arches National Park. Salt made it happen!
Moab was an ancient kingdom situated along the East shore of the Dead Sea, a lake of salty brine in Palestine. But it is not the subject of this post. We are dealing here with a more recently founded place, settled by Mormons at the outset, as so many other cities in the Four-corners region. It is the only city in Utah placed in the Colorado valley. What has this latter-day Moab, a tourist center, got to do with salt, you may well ask?
In fact, salt lies at the bottom of Moab's whole existence, in many respects. You may be surprised to hear that the town is situated in the middle of a piece of real estate, with a a radius of some 150 kilometers, which harbors one of the biggest deposits of mineral salt in the world. Covered by sandstone, there lies resting, some 150 meters below the surface, a layer of that crystalline medium almost TWO KILOMETERS thick. This is the Paradox Basin we are talking about here, stretching South almost to the border with New Mexico, and encompassing both Arches and Canyonlands National Parks.
A salt layer of such enormity has some peculiar geologic properties, which were discovered by the experts only recently. You will find no mentioning of salt in early brochures of the National Park Service (Yes, I am still safeguarding the booklets we received upon our visits more than 30 years ago), whereas the modern brochures all take care to explain the role salt has played in shaping the environment hereabouts.
|Moab Valley. Created by salt!
Huge domes of salt have been created this way, hidden under their roof of sandstone. But the latter is not as plastic as salt, so when lifted up by the rising salt dome, it fractures into fissures. Eventually, the sandstone cupola (that can have a radius of several kilometers) breaks up into upward standing slates and would to us, flying above it, look a bit like enormous stones fitted into a valve or valved bridge.
As water starts siphoning through all those cracks between the vertical slates, the salt beneath starts dissolving and the bubble sinks back to itself. In many cases, this process comes to a halt, when the overlaying crust of sandstone gets back to its horizontal position. However, the cracks have remained and erosion continues. Eventually, the slates´sides will be shaved off and they start standing freely as so called Fins, as in the title picture. Over time, some of them are ground down completely and the remaining getting sanded down by the wind into sleeker and sleeker shapes. Holes start to appear in those fins and – Voilá! – an Arch is born. Delicate Arch is a good example of just one of many on the plateau.
|Balanced Rock, Arches. La Sal mountains in background
We said above that the salt bubble usually stops sinking back when the upper layer retains its roughly horizontal position. But there are exceptions. If the original fissures are large and remain to feed the underlying salt with water even then, the dissolving continues and the sandstone layer eventually is hanging freely over a void. Of course, it collapses soon after and the result can sometimes be a huge valley, several kilometers long and up to one kilometer broad. These are the so called Salt Valleys. Moab Valley, which you can see above, is an example of such a construct.
When you journey to Moab for the first time, you may believe that the Valley has been shaped by the Colorado River, like so many canyons in the area. It is true that the Colorado runs through it. But it does so at an angle. The aerial view shown below demonstrates, how it has cut its way through the sandstone layer, coming from Colorado in the West and is now flowing into Moab Valley, which has been shaped by other forces. The valley is seen in green, with the town in the lower part of that green.
|Aerial view of the Colorado entering Moab Valley Source: Grand County, Utah
Besides the fins, there are also numerous arches to admire, I count at least ten of them. However, as usual, we concentrate on the most scenic ones, Landscape Arch and Double O Arch. To see them both, you have to take a hike of some 5 hours (roundtrip), but it is worth it. So let's get on with it and tell about the trail's wonders as we go.
|Devil's Garden Trailhead, Arches. La Sal mountains in the background
|Sandstone Glow, Devil's Garden, Arches
|Looking back at the "Narrows". Trail on upper right
Nowadays you are completely forbidden to repeat this act – not that I had thought of doing it again! You can't even go near the Arch anymore, not to speak of rambling under it to admire its span. There is now a only a fenced-in path at a distance, allowing you to inspect it without getting too close.
|Fenced in Trail below Landscape Arch
The safety reason is less subtle: In 1991, a slab of rock the size of a large bus was falling of the Arch with a tremendous tremble and noise. The few lucky enough to see it reported that they feared the whole structure to come down. No one was hiking below or on the spider-thin bow just then, so no deadly accidents to report here, I am afraid. But it woke up the authorities and, ever since, access to the Arch is strictly forbidden. Will the Arch last throughout my lifetime? I doubt it. It really looks dangerously slim to me now; don't you agree?
|Landscape Arch, Arches. The slimmest of the slim, but also the longest in the world
The trail starts with a steep incline, where you have to climb one of the many Fins adorning the environment here. They are not as fine limbed as the ones you see in the title picture, more like whales with broad shoulders, but with VERY STEEP SIDES to climb and descend, which makes some awkward going forward now and then. The picture shows this first ascent. Fortunately it will dissuade any disabled old geezer to dare continue, even if I myself did not show any hesitance at that moment. The climb does not look very arduous from above, where I was standing, but the upward slope is actually rather pronounced. In the far back, you can see once again the "narrows" that started the whole exercise.
|Arduous start of the "Primitive Trail"
|On top of a "whale fin". Tavaputs Plateau on the horizon
I have to admit that I fell in love with the fins and the marvelous views they had to offer. Luckily, a fellow traveller was kind enough to take my picture, when I was standing on my absolute favorite, with red cumuli all around me and the La Sal mountains glistening in the background against an azure sky.
|Emil Ems on Sandstone Fin in Devil's Garden, Arches. La Sal mountains in background
|Approaching Double O Arch, Arches Courtesy Lars Ljungberg
Now to the somewhat embarrassing part of the story. It is difficult to see on the picture, but underneath the lower "O" of the Arch is a vertical ledge, almost two meters high, which you have to climb in order to pass over to the Arch's other side; only there will you enjoy its magnificent fullness.
I did not bother to climb that ledge on the first hike; what is the use of a magnificent vista, if you cannot catch it on film? But I forgot my limitations as climber! On the second hike, when I went alone, I simply could not find ways and means of climbing that damn ledge. It proved simply too much for me! I waited under it for at least half an hour, hoping for a strong youngster to come along and give me a shove. But nobody came! At long last, I was forced to admit defeat and take the long hike back. To show you what I have missed, National Park Services have come to rescue. They have a huge stock of pictures from their parks on Internet, all of them excellent, and I am really grateful to be able to show this one:
|Double O Arch, Arches Courtesy National Park Services
|Devil's Garden, Arches. Path back to Trailhead
|Cotton Wood on Courthouse Wash in late afternoon, Arches
|The Organ, Arches
|The Courthouse Towers, Arches