At some point, we stumbled across a monorail. We hopped on, not sure where it was going; it turned out it was going to the Excalibur, the big fake castle we passed on the way in. We got about 50 feet into the Excalibur, and started looking for the way out; neither the Luxor or M. Bay gave off the miasma of stale smoke and cheap, meretricious, gum-mashed-into-the-carpet downmarket failure and desperation that the Excalibur did. I think the three casinos are owned by the same company, and split the market up thusly: Mandalay Bay, posh high-end customers; Luxor, mid-market; Excalibur, bottom-feeders. The M. Bay and Luxor each had some veneer of attempted style, or, at least, kitsch, to gloss over the tawdry point of their existence, but the Excalibur just had unhappy-looking people and decrepit decor.
Our suspicions were reinforced when we realized that while it was a simple thing to get on the monorail to the Excalibur, getting back on the monorail out was a different story, as though the builders didn't want to make it too easy for the hoi polloi[1] to wander into the tonier parts. We eventually gave up on the monorail, and dared venture out into the heat to walk back to the Luxor. By this time it was evening, and the daughter wanted to go for a swim. She and I left the room (5th floor, pyramid; the nice rooms are in the adjacent towers) and discovered it was really not that easy to navigate the place; eventually we found the pool, and found it closed. Closed! at 8:00pm! In freakin' Las Vegas! Shouldn't pools in Las Vegas be open 24 hours a day? With light shows and poolside – no, not pool-side, but in the pool itself – bars? What's the deal here? Faugh.
The next morning, we decided we had the time to go for a quick swim[2], now that the pool had deigned to open and let us in. Thus our one and only picture of Las Vegas:
That's the wall of the pyramid on the left, and, obviously, the M. Bay in the distance. THE hotel is PART of Mandalay BAY, as FAR as I could TELL. Notice discarded beer cans on the little 'island' in the lower left hand corner. Faugh, again[3].
[1]"The term often appears as "the hoi polloi". Some pedants object to that construction, claiming "the" is already part of the term. If you find such people, tell them to go study gebra and drink cohol." – Anu Garg
[2]We were wrong; we didn't have the time.
[3]Yes, I know. We went expecting to have a bad time, and we had a bad time. No surprise there, but we expected to have a better class of bad time. Maybe if we weren't such cheapskates...
Moira and I had only a mild amount of curiosity regarding the bright lights of Vegas, only because so much of contemporary popular culture makes reference to it in some way. On a personal level, however, I don't think there are any two people on the continent who are farther outside the target demographic for the Las Vegas Tourist Bureau.
On the other hand, the daughter seemed fascinated by the tawdry cheesiness of the whole Las Vegas concept, and, indulgent dad that I am, I decided to let her wallow in it for one night – I booked us all a room at the tawdriest, cheesiest, most garish place in Vegas I could think of – the Luxor. What the hell, Moira and I thought. Maybe we can appreciate it as camp. But we were not predisposed to have a good time.
We drove into town in the late afternoon and fairly quickly found the right exit. East on Tropicana. The first intersection, the Strip. An Epcot Center-like miniaturized Manhattan on the left, a big fake castle on the right, plain old big hotels across the way. Right on the Strip, and a big concrete Sphinx hove into view just past the fake castle. This is the place!
Being in Maximum Cheapskate Traveller mode, I waved off the valet parking,[1] and found a spot in the U-park garage, hard up against the Interstate. We lugged our bags, as well as the cooler[2], the long way through the garage, across the pedestrian bridge over the pools, into the big pyramid, past Tut's Progessive Slots, and to the end of... an immense line of people waiting to check in. Apparently, Cisco Systems was having a convention at the Luxor, and several hundred Cisco-ites (Ciscoans? Ciscones?) had arrived at exactly the same time.
During the long wait (sultry waitresses dispensed free bottled water to the crowd), we got to examine the decor – again, sort of a Disney/Epcot version of ancient Egypt, with a large dose of The Ten Commandments mixed in. The inside of the Luxor's main pyramid building is hollow, so we could look up 21 or so stories to the apex. The casino floor was at ground level. A large terrace on the second floor contained a number of shops, restaurants and theaters all designed externally (there's that Disney feeling again) to have a sort of old-Cairo look. Great big signs advertised the theater shows. Apparently, the performer known as Carrottop has an exclusive gig at the Luxor for the rest of this century[3] – his huge orange head was everywhere. Three gigantic women wearing lingerie and vacant expressions advertised whatever variant of the Vegas topless revue the Luxor happened to be peddling.
Once we finally got checked in, we wandered around, checking the place out and looking for somewhere to eat. I had heard, long ago, that casinos in Las Vegas generally priced things like food and lodging low, to encourage people to spend more on gambling. If this was ever true, it doesn't seem to be true any longer. The restaurants at the Luxor were all more expensive than we felt like paying, so we ended up eating overpriced Little Caesar's pizza slices (cash only, no checks, no credit cards) in a food court adorned with big papyrus-head columns.
[1]Apparently, valet parking was free.
[2]Anti-bear tempting policy.
[3]Who is this guy? We'd never actually heard of him except as the butt of other people's jokes.
Ahem. As these picture-free entries lack that visual sparkle, I'll just throw in some leftovers from Utah that I never got around to posting before.
Desert varnish on the walls of Buckhorn Wash. (San Rafael Swell)
Hoodoos in shadow, with Brown's Point (10,930 ft), the southerneasternmost tip of the Aquarius Plateau, in the distance. (Bryce Canyon)
Window Blind Peak above Cow and Calf Canyons. (San Rafael Swell)
Eroded hoodoo remnants. (Bryce Canyon)
Mini-arches at the base of two hoodoos. (Bryce Canyon)
Sunset. (Bryce Canyon)
Bright and early the next day, we packed up the expedition vehicle for the day-long drive to that wicked, sinful place, Las Vegas. It still strikes me as a novel thing that Vegas is as close as it is to southern Utah – I'd always had a disconnect in my mental map of the southwest, where Utah, Colorado, Arizona, and New Mexico were all clearly contiguous and interconnected, but Nevada was off somewhere else. And California – well, that might as well be on some other continent from the Four Corners region. But no, the map did not lie -- it really is possible to get there (Vegas) from here (Utah).
So we head up into the Wasatch Plateau, past the rest area just west of the Rte. 10 junction. (Little did we know it, but this would be the last normal rest area we were to see for hundreds of miles.) Up past the Cretaceous coal beds that are the basis of much of what economy there is in east-central Utah, over the 7900 feet of Emigrant Pass, up and down into the valley of the Sevier River, with the brilliant red sediments of the Pavant Range to the west. Now south, with the unexpectedly high (12,000+ ft.) Tushar Mountains, remnants of relatively recent volcanic activity, sticking up above treeline on the southern horizon.
West and up again over the southern end of the Pavants. I-70 finally drops down for good, dead-ending into I-15 right in front of a prominent cinder cone, the most obvious bit of volcanism remaining. From here, we head south, through a series of densely agricultural valleys, the hills and low mountains to the west screening the view of the Escalante Desert, the first taste of the Basin and Range province. To the east, the land rises sharply along the Hurricane Cliffs, jumping up 3000 feet to the highlands of the Tushars, Kolob Terrace (from which Zion Canyon is cut), and finally the Markagunt and Paunsagunt Plateaus. The cliffs are the surface manifestation of the Hurricane Fault, an active hinge in the earth's crust; east of the fault, the crust is pushed upwards in layers of plateaus; west of the fault, the crust is dropping down and being stretched thin in the distinctive landforms of the Basin and Range.
Continuing south, past Cedar City; I recall seeing Coriolanus here, thirty-three years ago (thirty-three years!) in Southern Utah State College's replica of the Globe theatre.
Previously, it was as far south as I'd ever gone on this road, but now we drove on, and quickly started to lose altitude. We dropped down about 2000 feet to St. George, the "Mormon Las Vegas" (because of the climate, not gambling). By this time, we're low enough that the local climate is very dry; higher up, we could expect to see conifers, at least, but now we're surrounded by desert scrub and rock. The road finds the Virgin River and follows it westward. Soon, we discover we've wandered into Arizona. Hey, another state to add to the trip! The Virgin cuts a spectacular canyon through the rocks as it drops off of the last remnants of the Colorado Plateau onto the low deserts of the Basin and Range (sorry, no pictures).
The river canyon dumps us out onto a low alluvial plain, covered by sparse brush and the occasional joshua tree. We cross the state line into Nevada, and are immediately confronted with Mesquite, a sort of mini-Vegas for those Utahns to impatient or uninterested to travel the full distance. In the distance are rugged black mountains that look like the refuse from a blast furnace. Slowly, the road drops, then rises again as it mounts the alluvial skirt surrounding the blasted mountains. Eventually, we reach the summit, where the road crosses over the highest point of the pile of eroded debris, and then down the other side, where another range of bleak rugged mountains is silhouetted against the horizon. We drop until we reach the limit of this range's erosion deposits, then rise again as we climb the debris of the next range to the west.
By now, it is late afternoon, and quite hot. Part of the thrill of the trip is watching the car's temperature gauge climb, slowly, to regions it has never before reached. As we climb the alluvial fans, the gauge rises. As we descend the far sides, the gauge falls. The road is busy, but the landscape is empty – except for the city rising out of the plain to the south.
After dinner, we picked up some fresh melons at a roadside stand, and started the long drive back to our temporary home. (Melons were excellent, too.)
This ends the Utah part of the trip. Next: headin' to Vegas!
My favorite review of a Ray's Tavern is this one, even though it isn't "our" Ray's Tavern (I don't think... it's not easy to tell.)
Once again, I suppose it would have helped to put some of those things, what do you call them, "people", into the photo to provide a sense of scale. According to the topo map, these monoliths rise about 400 feet above the streambed.
The streambed itself if full of fascinating and beautiful products of erosion, none of which we took pictures of. At this remove, I don't recall why not, but there you have it. Water-carved potholes, chutes, pools, places where the sandstone has been sculpted as though it were cake icing... you'll just have to take my word for it, because the only thing we took pictures of were these rocks.
Finally, the streambed exits the small canyon, passing by two remnant towers, the "Tower of Babel" and the "Organ". This one actually has some size cues in it; if you look closely, there is a little bitty pickup truck in the center of the image.
At the end of the trail, hot, footsore and tired, we glug down several pints of water and pack up. Next stop, Ray's Tavern.
[1] The classification of rocks is every bit as byzantine as the classification of species.
We at Progressive Reactionaries appreciate your applying for the position of Lieutenant Governor for the state of Iowa.
Unfortunately, we interviewed many applicants and intend to select another individual whose credentials and qualifications were better suited to our needs.
Thus we will not be voting for you, but thank you for your interest.
If a need arises for us to contact you in the future, we will do so and you have our continued good wishes.
Very truly yours,
Thank you. Next!
This arch is more elaborate than the name "Double Arch" might imply. From the top of a wide, triangular fin of sandstone, erosion has carved a deep hole – and then punched large arches through two of the walls bounding the hole. Standing in the middle, you are effectively at the bottom of a wide well, with an arch on either side of you.
In the bottom picture, you can (if you look carefully) see both arches, plus a little bit of sky showing through from the top of the "well".
Also, you can see more incipient arch formation off to the right... Entrada sandstone just isn't happy if it can't make an arch.
This arch was used in the beginning sequence of one of the Indiana Jones movies – though the train sequence immediately following was filmed one state over.
Anyway, catching back up with the tour... because it was so stinkin' hot, we cut back on our hiking plans. We did want to see Landscape Arch, though, so we joined a steady progression of tourists tramping between the Entrada fins towards this longest-of-all-arches.[1][2]
The previous two times I'd been here, the trail climbs up to and then passes beneath the arch, allowing you to look back across the landscape, the view framed by the arch, thus the name. Since then, however, the long, thin arch has been making itself thinner, by splitting off tons of rock from its underside.[3] The Park Service, understandably not wanting flocks of lawyers to descend were some hiker to be squashed by a few tons of sandstone, has closed off all public access beyond the point at which I took the picture:
Most of the small bits of rubbly stone in the middle of the picture are from the '91 and '95 rockfalls. The rock split off from the thinnest portion of the arch, at the center and right of the span. (I think that somewhere, I have photographs that I took of the arch in 1973. If I can ever find them again[4], it would be interesting to compare them.)
For a very different perspective, here's an aerial view of Landscape Arch (image 122-22, about a quarter of the way down the page[5]), that makes it look even more improbable. That page also has lots of nice views of Arches from the air, which really show that the Entrada sandstone layer has split into thousands of parallel fins along the ridge that makes up the park.
[1]"290.1 ± .8 feet long, a height of 77.5 ± .5 feet, a width of 18.0 ± .5 feet, a thickness of 6 feet, and an opening breadth of 295 feet."
[2]Or is it?
[3]One or two arches collapse per year in the Park.
[4]Moving often, we tend not to accumulate or retain things, sometimes even things that more rational people would hang on to. "Hey, where's X?" "Oh, I haven't seen that since Colorado." Etc.
[5]The same page also has aerial views of Delicate Arch (123-04) and the Priest and Nuns (123-14).
We travelled on, past the Fiery Furnace (quite fiery at this time of day), past Sand Dune Arch and Skyline Arch, and were lucky to find a place to park at a picnic ground near the end of the road. In addition to the heat, the wind had picked up quite a bit, and so we tried to find shelter from both. The picnic ground was located between immense vertical fins of Entrada sandstone, which helped to block the wind, but also caught the sun's heat and reflected it back to the ground, making things even hotter; but we were canny enough to stake out a picnic table located in the shade of a large, though not particularly enthusiastic, juniper tree.
The picnic ground was crowded. Most of the people there appeared to have come off of a large unmarked white tour bus, and all were speaking Italian.
(Parenthetical note that shall become the remainder of this post: A striking thing on this trip was the shifting proportions in cultural and ethnic affiliation among park visitors at the various parks and monuments we visited. In southern Utah, it seemed – no actual data were collected, or anything – that most visitors to the park were speaking Spanish, French or Italian. In fact, we wondered a few times if it wasn't the same group of French and Italian tourists following roughly our same route. Either way, people speaking American-accented English were a distinct minority in Bryce, and maybe about 50% of the population in Canyonlands and Arches. I suspect Zion and Bryce get more of the tourist trade by virtue of being about a day's drive from Las Vegas. A lot of the RV's we saw in Utah – and we saw lots of RV's – were rental RV's with California plates. We assumed that tourists fly to Los Angeles or Las Vegas, pick up their RV, and lumber off to Utah with them.
The relatively large numbers of French-speakers surprised me; if anything, my prior experiences in national parks had me braced for yet another lecture from some backpack-toting German about how Americans didn't properly appreciate the National Park System (true enough, I'll grant). The proportions of the various (presumptive) nationalities changed as we headed from one park to another. In Sequoia, there were more 'murkins, maybe 60% or so, and most of the apparent foreigners were speaking Chinese (quite loudly, I might add). In Yosemite, German accents finally showed up, as well as British and 'Strine – the proportion of foreign accents crept upwards of 50% again. When we moved inland, the proportions of presumptive foreigners dropped - to maybe 25% (Chinese and German) in Grand Teton, and 40% or so in Yellowstone. When we moved deeply inland, to Little Bighorn and Badlands, I didn't notice any non-North American accents at all.)
Hmmm, that's not that interesting a picture, is it? I'll throw in another one. This one's a big rock, fallen off the underside of Double Arch (coming up in a bit).
We drove back downriver, turned right at Moab, and into Arches National Park. Flashed the pass, and drove up the wall of sandstone behind the entrance station. It was already pretty hot, even though it was partly overcast. The plan was to be well out of here by nightfall, so we didn't have a lot of time to look around; what to do first? The Windows section: probably crowded, not much hiking. Park Avenue: no arches. Fiery Furnace: well, the name kind of sums that up. The best balance of getting out and hiking, actual archy scenery, and degree of difficulty? Probably the Delicate Arch trail.
So, past Balanced Rock; past the slow parade of RVs turning off towards the Windows section; down into the Salt Valley, then right to the parking lot for the Delicate Arch trail, at the foot of a strikingly copper-green hill – not vegetation, the rock of the hill itself, bright blue-green. I think this is Jurassic-era Morrison Formation siltstone, which would normally lie atop all the exposed rock here, but has slumped down into the collapsed salt dome which forms the Salt Valley. The Morrison is well-known among the geologically inclined as being a very rich fossil-bearing strata. Many of the classic dinosaur finds in the western U.S. came out of Morrison beds in Colorado, Utah, and Wyoming... oh, God, I've wandered off into geo-pedant land again. Ok, I'll stop now.
Some scenes, even though they are the most goddamned clichéd things imaginable, just force me to take pictures of them. A million people could have taken the exact same picture before, and most of them better, but I just can't help myself – must ... take... this... picture... of.... the arch.....
(Some random guy in there for scale.)
Now that I think about it, Arches was the first national park I ever visited ... or was it Bryce, or Zion? It was a long time ago, when I was 11, and all part of the same trip, so I don't remember which one we did first. I remember Bryce and Zion as being unpleasantly hot, but Arches as cool, almost uncomfortably cold and overcast. I don't remember what month it was, but it was probably in the late winter or early spring. I remember walking along the last parts of the trail to the Arch, in the face of a numbing wind, wearing only an inadequate light sweatshirt. I didn't know it at the time, but before the trail gets to the arch, it passes another small arch – more of a window, really – that looks over Delicate Arch and the slickrock bowl it presides over.
From the Arch, you can look back towards the west and see most of the trail route, all the way back to the parking lot. Conversely, if you know what to look for, you can see the Arch from much of the trail; but you're looking at it end-on, so it just looks like another sandstone knob.
The slickrock bowl is a pretty distinctive landmark on its own; here's the satellite image of it. It looks a little like a big ear.
The arch, and the slickrock bowl next to it, and basically all the arches in the park are formed from Jurassic-era Entrada sandstone, which lies above the Navajo sandstone, which means that the Entrada is some of the youngest rock in this area. If I may be permitted another moment of intense geo-geekliness, Entrada is my favorite sandstone; that salmony-orange color, the way it erodes into such smooth, ropy curves, the neat little handholds that form in it. It forms fantastical shapes, like the Claron Formation does at Bryce, but it's harder, and forms larger, longer-lasting structures, like the arches and the towers of Park Avenue.
Admittedly, that's still not very hard. Apparently, Entrada is considered poor climbing rock; it's too soft and brittle to assure good hand and footholds if you're trying to hang your whole weight from them. This past May, a rock climber, and his crew, all climbed the arch, late at night, and then the crew filmed the climber doing it again at dawn. There's still controversy (much controversy) over whether the climbs did any damage to the arch – close-up photos of the top reveal what look like rope scars. The climber got himself in a lot of trouble with the authorites, who then discovered, to their chagrin, that there was no actual prohibition to climbing the arch on the books. There is now.[1]
In the two prior times I'd been to Delicate Arch, I'd always wondered what things would look like from the bottom of that slickrock bowl. I'd never seen anyone go down there, and I don't recall ever having seen any pictures from down there, so down we went. It's a neat little spot, and must be quite impressive in a downpour – all the rain drains down into the bowl, which then creates a short-lived body of water in the bowl, or overflows over the rim of the canyon in a 300-foot cascade.
On the way up, we'd passed several small pools that just looked like brief temporary puddles on solid rock, but at least one of them had tadpoles living in it.
[1]The climber was sponsored by Patagonia, who initially set up a press conference touting the climb. After the overwhelmingly negative response news of the climb engendered, Patagonia backpedalled feverishly, saying they knew nothing! nothing! about the climb or the potential legal issues involved.
Geologic detour ahead
Deep underground, this whole region is underlain by the Paradox Formation, a thousand-foot-thick ancient layercake of salt deposits and shales deposited during the Pennsylvanian epoch, about 300 million years ago. Since then, many thousands of feet of additional sediments have been deposited over the area, and the volcanic La Sals have punched up right through the middle of it all.
Over the past 65 million years, large salt domes have bubbled up out of the Paradox Formation, pushing up the overlying strata; northwest-to-southeast trending faults in the strata allowed the entrance of groundwater into the domes, dissolving away the salt, and causing the domes to collapse along the faults. Many of the rivers and streams of the region already had well-entrenched courses, so the emergence of these new valleys had little effect on their drainage patterns.
End geologic detour
So, anyway, as I said, the Castle valley is one such 'paradoxical valley', running perpendicularly to the course of the Colorado. Following the river upstream, we drove past the valley mouth to take a quick gander at yet more rocks. Along the north side of Castle Valley, a remnant ridge of Wingate sandstone forms the features known as "Castle Rock"[1] and "Priest and Nuns" (the resemblance is more apparent from closer views).
A few miles further on, we came to Fisher Towers. It was pretty thoroughly overcast at this time, and we wanted to get to Arches, so we didn't spend much time here, and I didn't take many pictures. The Towers apparently have some nice hikes, though, and the rocks are pretty interesting. Once again the relatively harder cap rock (chocolate fudge swirl Moenkopi sandstone) protects the softer Cutler Formation mudstones and conglomerates beneath. The Cutler conglomerates are interesting by themselves, containing dark rounded pebbles eroded out of the now-vanished Uncompaghre Highlands[2].
[1]Yes, it frequently seems as though every third rock outcrop in the western U.S. is named "Castle Rock". The pioneers were not overly imaginative people. Though from the number of Devil's Thumbs, Devil's Slides, Devil's Postpiles, Devil's Towers, Devil's Lakes, Devil's Hopyards, Devil's Punchbowls, Devil's Gardens, Devil's Kitchens, etc., scattered about the country, a future historian could make the argument that they were all a bunch of Satan-worshippers.
[2]"Uncompahgre". I love that word. Hardly ever get to work it into a sentence, though.
We stayed at this place for the night. It's about 15 miles up the Colorado River from Moab, right on the river.
It is a fairly swish joint, but we didn't have the time or inclination to take advantage of most of its amenities. We did eat a very nice dinner in the restaurant, and the offspring and I swam in the pool, waiting in vain for the clouds to break so that we could see the stars. We did see a lot of bats fly over, just at the limit of the pool's lights.
Come to think of it, we saw a lot of bats, period, on this trip. Every evening that we were out in some naturalish spot, once dusk descended, the bats would come out. Which I guess is completely unremarkable, except it doesn't happen back in Hometown, Iowa – I'm not sure I've ever seen a bat there.
Warning: Heavy Geology Ahead
This is the center of Upheaval Dome, a very odd geologic structure just north of Island in the Sky, about four miles east of the Green River. The roughly circular structure consists of an outer syncline, an inner circular ridge of higher rock, then a deep, nearly circular canyon surrounding a central mass of highly deformed rocks. The image is from the rim of the inner canyon, and shows the extent of the deformed rocks in the center. For an idea of scale, the distance from the prominent cliff on the left to the top of the canyon wall at the right edge of the image is just slightly under one mile; the whole visible structure is about 2.5 miles across. While the circularity of the structure is obvious, what's not so obvious is the uplift; the rocks at the center of the dome have been uplifted about 1100 feet compared to their levels in the surrounding countryside.The outer cliffs in the image are Jurassic-aged Kayenta and Wingate sandstone, and the red talus slopes are formed of debris eroded from them. The grayish-whitish slopes toward the center are Triassic-era Chinle and Moenkopi Formation rocks; the brown rocks in the center are also part of the Moenkopi. In the mishmash of rocks in the center are small exposures of Permian White Rim sandstone, the oldest rock exposed here. The White Rim sandstone has undergone a lot of violence; in essence, the stratum has been broken into little pieces and then reglued together.
So the obvious question is: what did it? What pushed up the rocks so much, just in this one specific spot, and deformed them so greatly while doing so?
The prevailing opinion for most of the 20th century was that Upheaval Dome is the eroded-away remnant of a salt diapir; salt domes and other salt-related structures are very common throughout this part of eastern Utah and western Colorado. The idea was that a plume of salt had pushed completely through the sedimentary strata here, bulging the rocks upwards and greatly warping the rocks at the center of the plume. Then, erosion stripped away the overlying layers of rock and salt, exposing the rock layers disrupted by the salt plume's passage. There have always been some problems with the salt-origin hypothesis. None of the other salt structures in the region resemble Upheaval Dome, in size, shape, or geology; rather than being eroded away, the salt-bearing strata responsible for creating domes and diapirs appear to be at least 1800 feet below the surface of the Dome, and show no evidence of having produced a plume here; and there's no evidence in the center of the Dome of any, like, salt.
The possibility that the Dome might have been created by other forces was proposed in the 1930's, but evidence for those ideas was not seen as very compelling until the 1980's and 90's. The growing recognition of the large number of impact crater sites on and below Earth's surface has lead many geologists to reinterpret the Dome as being the remnant of an impact crater, and there are features of the Dome that are more characteristic of impact craters than other explanations of its origin, such as the presence of a distinct magnetic anomaly in the area, (rare) blobs of melted and recrystallized sandstone, and unusual fracture patterns in the rock that are commonly found in rocks that have undergone impact shock.
Here's a closer view of the center of the Dome. Notice how the strata are folded nearly vertical in many places. Harder to see (curse my amateurish photography!) are the pinnacles formed by these warped strata.
Most of these notes shamelessly cribbed from Kriens, Shoemaker, & Herkenhoff, "Geology of the Upheaval Dome Impact Structure, southeastern Utah" (yes, that Shoemaker). A more general overview can be found here. The best images I've found of Upheaval Dome, bar none, are here.
Update: More links! Good images, diagrams, and descriptions here, close-ups of the central rocks here, Google Map satellite image here, more Serious Geology with some nice images here.
