Tuesday, July 25, 2006

July 25, 2006

Glenn, here. After four days in the field I’m back in a spot with internet access (dial-up so bear with me) so the story continues….

After arriving at our traditional field camp by the Mother’s Day Site, I found that the crew had gone into town. Who could blame them as it was late afternoon and the mercury was still well above 100 degrees as it had been for close to a week. I set about organizing my own tent and gear, had a look at the dinosaur quarry, and sat down with a luke-warm beer to await the team’s return. They were back with supplies before I knew it and we caught up on progress to date.

I always have a subconscious fear that we’ll get on-site only to find that a disaster has befallen or that there are no more fossils to be found. Not a chance. In actual fact, we always find new material immediately upon arrival. Indeed, this year the first thing spotted was a very nice mid-series cervical (neck) vertebra of a young animal just coming to the surface and ready to be worked. This, after our best efforts to rebury the quarry with protective plastic, winter jackets and dirt and rock at the end of each season. The gully-washers that come through over the winter and spring nevertheless tend to expose new material each year.

Mason, Don Esker, MacKenzie English and Sara Oser (the latter, three students at the University of Cincinnati) had also uncovered a variety of other elements – a large cervical, an epipodial, and a series of four articulated mid-series caudal (tail) vertebrae, among other things. Plenty to work on and a great deal for the Field School participants to work on when they arrived on Monday.

That afternoon, Dale Gnidovec from the Orton Museum at Ohio State showed up with his volunteer Sam Perry as they do each year. These guys are great help in the field and Dale and I go way back to our early graduate student days in Texas. We all spent the night staring at the phenomenally clear sky, brilliant stars and counting meteor streaks (not strikes, thankfully), while telling stories of the “old days”, lamenting our disaffected youth (just kidding), and listening to the coyotes sing. The wildlife out here is great – I’d already seen an eagle, various rodents and lagomorphs, antelope (and turkeys a couple of days later). (We also saw and felt yellow jackets sadly, which this year were to be found in abundance for some reason. Most of us ended up with a sting or two before bringing in some traps to keep them away from camp and the quarry.) The old west is still there when you're camping out under the “Big Sky”.

For the next few days we split up – Mason, Don and Sara working MDS and Dale, Sam, Mac and I heading about 20 miles south the “Dodson Diplodocus” site. This is another Morrison locality near the Wyoming border found by local rancher Will Tillet (of Tenontosaurus tilleti fame) and worked by Peter Dodson and now us. Peter gave us the big sauropod they had begun to uncover as we’d been looking for a relatively complete animal to mount at Cincinnati. Big is perhaps an exaggeration as it is a young adult gracile diplodocid sauropod only 60 or so feet long, but as it’s largely complete and articulated, it’s a major engineering project to get it out of the ground (Peter, of course, knew that when he passed it on to us!). We’ve been at it four years now and only the body block remains. We hope to get the last of it this year.

So, all of this work continues apace, while I have moved up to the YBRA camp in Red Lodge. This is the Yellowstone-Bighorn Research Association and is a fabulous place to stay – rustic cabins on the mountainside, a grand old lodge with home-cooked meals, showers and real beds. I try not to miss the “old west” camping experience too much. I’ll be up here for the next three weeks with the Field School participants, taking in the scenery and commuting down to Mother’s Day to collect for the Museum. This first week we have a great group – seven people from all ages, walks of life and from as far away as New Jersey. Today, the school’s first full day, we did my grand geology tour of the Beartooths and Bighorn Basin.

We start up on the pass near Hell-Roaring Plateau (I love that name – you can imagine the winter storms up there!) and look at hard, crystalline basement rocks – granites, granitoids, mafic intrusions, various metamorphics, etc. – that underlie the North American continent, and here brought to the surface by major tectonic uplift during the Laramide Orogeny (starting in the latest Cretaceous and Early Tertiary). Some of these rocks are 3.9 billion years (with a B!) old by radiometric dating and are some of Earth’s oldest rocks. From here we move back down the Rock Creek Valley, examining Pleistocene montane glacial geomorphology, down into the Bighorn Basin through the Fort Union Paleocene beds and associated coal fields (now abandoned leaving a somewhat lonely town of Bear Creek standing guard – 100 years old this year – Happy Birthday BC!), and into the Clark’s Fork Canyon. Here is one of the best examples of Precambrian basement uplift, covered unconformably by 300 million years of Paleozoic marine sediments with the most spectacular drag fold and flat-iron palisades at the mountain front that you could ever hope to see (not to mention two great terminal moraines at the valley mouth. Lastly, we cross the basin towards the Pryors moving generally down section from Paleocene to Cretaceous to Jurassic. At Red Dome we get a tremendous view of Cretaceous Western Interior Seaway shales, Cloverly Formation badlands (type locality home of Deinonychus antirrhopus), blood-red Chugwater sands and mudstones (Triassic) and, of course, the famous dinosaur-bearing Morrison.

We do all this to place the fossils in context – the Earth is a dynamic, changing place on which tremendous geologic forces operate over vast time scales. Few places like Montana/Wyoming show this to greater effect. Tomorrow we dig in earnest!


jason d. said...

How are the milkshakes at the Bridger Cafe this year?

Glenn said...

Jason - Just as good as last year! You should try to join us here again next year. Cheers, G-

jason d. said...

That's the plan, Glenn...just hope some funding comes through to make it possible.