Perfect silence. It is 10:15 in the morning and I am on a hill twenty miles north of Thermopolis and a half a mile off the highway. We got here at 9:30 AM and the temperature was about 70 degrees. It was 49 just before dawn at the motel. By 11 AM it is at 85 degrees. Yes there is low humidity but it is still hot as Hades (Google that!). The only green we see is sparse, dried out sage and an occasional cactus. The glaring desert sun bakes you even at 9 AM in the morning. I have so much sunblock on that I look like latex man. The air is clear, the sky a deep blue, and there is no humidity—little water vapor—to filter the sun. We’re out on the high semi desert. This morning there is not much wind for a change. Often it is very windy for no apparent reason on the arid plateaus. (As in: they call the wind Mariah). It is partly cloudy above us. But definite rain clouds have formed over in the western mountains and, as well, there are some to the north. This presents an interesting contrast—deep blue sky above and menacing black clouds in the distance. In Ohio we don’t often see that contrast. Typically, the whole sky gradually turns gray and it eventually starts to rain. These desert rainstorms, on the other hand, are much different. For one thing, you can see them coming for 50 miles away. In the storm north of here I can see occasional bolts of lightning that appear to be hitting the ground though I cannot yet hear thunder. You don’t see forest fires here from lightning strikes or burned areas from prior wild fires that you encounter in the mountainous areas because there is nothing to burn on these semi deserts, no fuel. From the cloud’s direction it looks like the one squall will stay north of us. You can easily track the cloud shadows on the light colored cliffs and establish the storm’s direction. The surface wind, however, may well be opposite of the storm direction.
I am told by the geologists in the field with me that the dirt we are walking on, collecting on –light gray colored sediment— is Permian in origin, deposited maybe 50 million years before the dinosaurs and is oceanically deposited in nature. That is, this sediment was laid down in the bottom of a sea, layer after layer, over time. Above it are distinctly red cliffs, mountains of Triassic rocks –formed at the beginning of the age of dinosaurs. This is, technically, the Morrison Formation, a terrestrially laid down deposit (formed by shallow lakes, flood plains, wind deposits) rich in iron that is known for its Allosauruses, Brontosaurus and such. It is about 250 million years old. If I were a much younger man I would walk these hills because whole dinosaurs are known to be found eroding out of the cliffs. Woulda, shoulda, coulda! Alas, I am now an older guy limping around about the desert pretending to be a geologist, pretending to know what I am doing.
It is sooooo quiet out here this morning. We turned off the main road onto a dirt road that is in fact an officially listed Wyoming Township road. It apparently leads to gas and oil wells and open range and goes on for twenty to 40 miles. The main highway is a ½ mile in the distance. Back in Ohio we rarely really need 4-wheel drive to get about, even in winter. If you wait a couple hours the roads will be plowed by the city, township, State. Out here in Wyoming though, all-wheel drive is almost a necessity even in the summer. Even the school buses are 4-wheel drive. One pickup truck actually did go by us as we worked, probably checking the oil wells. So the vehicular traffic might in fact average as many as 3-4 vehicles per day on these dirt roads.
I am walking these hills, head down, watching for abnormal shapes lying about the ground. The fossils are typically made of much harder stone than the mudstone surrounding them that quickly breaks down into dirt. Thus every time it does rain a new crop of fossils are exposed at the surface. I see big rigs and cars go by on the state highway but I hear nothing, not even the wind. Out here in this semi desert, I see what appears to be miniature volcanoes in the center of large cleared rings around it. These are ant hills– colonies of red ants. I wonder what they are eating so I watch them carefully. They are apparently carrying little bits of plant material and seeds into the nest. There certainly is not much in the way of meat out here. I am told to examine the mounds carefully because the ants frequently deposit fossilized sharks teeth on the ant hill—things that they have dug out and discarded. Occasionally I see remnants of animal bone likely caught and eaten by ????? and probably the ants finish off the remains.
When we are out here in the high semi-desert we have to keep a close eye on these “poppers” as they are referred to—thunderstorms, and track them. I am watching a developing thunderstorm that appears to be coming right at us from the west. I have not seen lightning yet but a definite squall line with obvious rain coming down. How far away? Hard to estimate because of the land distances are so great. But, probably sometime in the next ½ hour to an hour, it will hit. I just saw cloud to ground lightning.
Oftentimes the rain is concentrated in clusters, small areas only, and surrounding areas get only a few sprinkles. But if you are in one of these poppers in the field and you get a downpour, frequently there is hail and no place to hide. And you Mr. Lightning Rod, are also the tallest thing for miles. The desert you are walking in is not sand but a dry, clay based, fine-grained dirt resulting from the breakdown of shale rock and water. The water and clay make an instantly slippery coating that sticks to you like wet pie crust or bread dough. Combined with the erratic surface of the desert, this will be no fun walking through.
By about 10:30 we decide we had better head back to the truck and get off the dirt road and back on blacktop, asphalt before the thunderstorm hits. The total take for the morning collection: I’ve picked up a reasonably good ammonite about the size of a half dollar and several small broken pieces of ammonites. Likewise Carrie and Rod have also found similar ammonites and pieces plus some clams. We had hoped to find some sharks teeth but didn’t have any luck. The ants apparently didn’t have any luck either.