U-DIG QUARRY, UTAH
In early June, after visiting Zion national Park, we wanted to do some fossil hunting. U-Dig is a well-known quarry near the town of Delta in western Utah. Utah is a much larger state than it appears to be on a map. We left St. George in the southwest corner at around nine in the morning and drove north. We drove and drove... We finally made it to Delta in the early afternoon and headed west as the only car on Highway 50, often called the "loneliest road in the U.S." for another hour and after fretting that we may have gone too far, finally came to this sign. It was now around 3:30. So much for a day devoted to digging.
The 20 miles was a very dusty and bumpy drive on a dirt road, trailing a dust plume visible for miles. Given the amount of dust that coated the car, I was surprised that there was any left to be airborne.
Here is the quarry, in the House Range. The small building is the business office and the piles of grey rock are absolutely loaded with trilobites. We were greeted by an amiable and helpful quarryman, Gene Boardman, who loaned us geology hammers and buckets before leading us on a winding path through the heaps of shale and let us go to work looking for trilobites. For much of the time he was busy elsewhere among the mounds, but came back frequently to see what we had found and to direct us to promising areas. We learned it was more productive to look for natural fractures in the layers of shale rather than simply pound on a rock in the hope it would split to reveal a fossil. Our skill at spotting fossils among the "float" quickly developed. At first we kept almost every rock that had a fragment of a trilobite, but as we found more complete specimens, we became more selective.
Janis is doing her chain-gang thing.
Standard procedure in the quarry seems to involve making a pile of keepers. However, the next step is to spot another potentially productive area far enough away that you don't really want to haul everything along, so you leave it with every intention of coming back for it later. A look around quickly reveals that there are a lot of piles that were forgotten or were just too heavy to haul back to the car. Looking through those caches was often very productive.
If I didn't mention this, it was unseasonably hot. Temperatures were in the high 90's, but we tried to keep chugging water and didn't really notice that we were getting dry until we got back in the car and pretty much drank everything in the ice chest. We were in the quarry for around two and a half hours. Then it was another 45 minute drive on the dust road back to I-50 and we headed west toward Baker and Great Basin National Park just across the border in Nevada.
Gene Boardman is on the left with his truck. I found that shorts were great for keeping cool in the heat, but lousy for kneeling among jagged shards of shale.
Neither of these have their free cheeks, but the Alokistocare is fairly uncommon in the quarry.
The larger trilobites are Elrathia kingi, the smaller ones may be Bolaspidella species and there is one Peronopsis from a different area of the quarry.
I think this is a little (4mm) Bolaspidella.
This little guy is beside himself, or at least his cheek is.
I was loading the car when I looked down and saw this double sitting in a pile of float.
I had no idea that I found this bug. It was under a crust of mud on the back of a rock with a cluster of Elrathias. I decided to dip the piece in a bucket of water to wash the dust off when I got home and when I pulled it out, the mud had washed off and got my first look this two inch beauty.
Here is our haul. The U-Dig fossils are the dark shale pieces. The lighter brown material is from Oak Springs Summit in Nevada. The big piece of light grey rock under my third button is the one with the Asaphiscus. I ended up leaving a lot of these rocks on a bench in the back yard and after a few seasons of rain and sun, the shale revealed some new cracks and some extra splitting revealed even more trilobites.
For more information on the U-Dig Quarry, please check out their Website.
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