The Natural Geologic Laboratory of the American West
Earlham Geosciences Department
2004 Off Campus May Term Course
Ron Andesite Anatexis Katespar Jessper Gabbro Gravesite Natite Hoeyite Tessite Peakeite Scottite Tayloalbite

Day 3: Sunday, May 16th, 2004


Florissant Fossil Beds - Collegiate Mountains - Rio Grande Rift - San Luis Valley - Sawatch Mountains - San Juan Mountains

Mueller State Park and Florissant Fossil Beds NM Collegiate - Sawatch - Sangre de Cristo Ranges To Nate's Cabin near Jasper, Co. in the San Juan Mountains


By David Peake


Day 3 of our trip was mainly taken up by driving through Colorado looking at great sceneries. If anywhere but the west, the amount of driving probably would have seemed a bit dull but the west filled us with a better understanding of nature’s ways and beauty.

Proceeding through pine forests interrupted by grassy meadows with Pikes Peak visible to the southeast to get to our first stop, Florissant Fossil Beds National Monument, the drive seemed harmonic and delightful. Discovered by Dr. A.C. Peale of the USGS in 1874, the park exhibits 34 to 35 million year old catastrophic volcanic events by the Guffey volcanic center about 18 miles to the southwest. Alternating between lahar and gaseous eruptions, Guffey destroyed and preserved different forest and lake environments that give Florissant Fossil Beds National Monument a rich fossil display. About 60,000 to 80,000 plant and animal specimens have been discovered in the beds of which 1,100 are insect species, 114 plant species and several fish, bird, and animal species. We made a quick look around the simple visitor center filled with mostly plant and insect fossils before taking a mile long trail to look at petrified Sequoia trunks. Living during the Eocene Epoch in an ice free world, the trees have since been excavated exposing them to the environment causing them to deteriorate quickly. Looking at 7 different trunk remnants, most having metal support pegs and rings, each gave a little different insight into the sequoia structures or history. Some of the trunks stood about 12 feet high with 10 feet diameters showing oxidation giving red and yellow colorations. Others had visible root structures or visible tree rings. One of the larger stumps even had saw blades stuck into the stone stumps where pioneers tried to cut out pieces of the ancient sequoia.

After we left the park we continued down Highway 24 driving along the scenic Collegiate Mountains. We stopped at an overlook, scrambled up a road cut with loose rocks and awed at the snow peaked mountains and the valley below. While in a valley we encountered Pennsylvanian halite evaporites indicating an ancient dried up lake. An hour or two more down the road we stopped again at an elevated area to see the Rio Grande Rift with the Johnson Village along the Arkansas River below us. From here we got great shots of Severio, Antero, Princeton, Yale, Harvard and Columbia Mountains, aka the Collegiate Mountains. Continuing through the Rio Grande Rift the Sawatch Mountains became visible. Ron originally recognized that we are out of the Collegiate Mountains range because the new mountains display different compositional and erosional habits but incorrectly hypothesized that they were the San Juan’s. After reading up on the area Kate concludes that we are most likely in the Sawatch. The moral of the story being Ron does not know everything.

Somehow during the first few days of the trip we somehow simply lost a sleeping bag. We stopped in the small town of Salida and wasted about an hour looking for a place to buy a reasonably priced sleeping bag and ended up going to a Wal-Mart and finding a great buy along with getting an inexpensive dinner. The mystery of what happen to the sleeping bag was never unfolded.

Continuing down the road through the San Luis Valley, we made a few more stops to look at road cuts and scenic overviews. We stopped and looked at the Sangre de Cristo Range showing great examples of glacial erosion and deposition and alluvial fan systems. To the south we could see ourselves approach and then pass the Great Sand Dunes, a previously planned stop but after wasting the hour in Salida decided unfortunately we did not have enough time to spend there. To the south the San Juan Mountains became visible.

We knew that we had left the Sawatch Mountains and had entered the San Juan Mountains when we started to encounter Tertiary igneous rocks. We stopped at a road cut and saw evidence for huge volcanic eruptions that hurled 5x5 foot rock bombs into the air. Some of the rocks in the volcanic debris show layers indicating that a stratigraphic volcano simply blew itself up. One road cut we stopped at showed some interesting volcanic history. The bottom layer consisted of the conglomerates that included everything from the huge bombs to sand and silt size particles indicating explosive volcanic activity. Directly above the conglomerate layer was a powdery crumbly white lapilli layer formed from volcanic ashes. Topping the lapilli is black vesicle filled basalt with olivine indicating evidence for ahah and mafic basalts.

The San Luis Valley being a semi-arid environment may make one come to the conclusion that the valley would be dry and brown. To the contrary, the valley contained lush green grain fields with huge irrigation systems spurting out copious amount of precious water. Field after field the farmers have for some reason decided that this environment is just fine for their crops. We took pictures so Ron could use these farming tactics as bad examples of water usage.
The San Juan Mountains proved to be our resting place for the day. The only problem with setting up camp, however, was finding the location. We were following State Route 15 when we turned off onto a dirt road called X Rd. Truthfully not a very welcoming name for a road to me. The road was in good condition but definitely a little nerve wrecking or exhilarating depending on the person when we took hair pin turns that if missed would mean certain death. The road followed a little stream through the glacially carved U-shaped valley with a steep uphill on one side of the road and a fierce sudden death drop on the downhill side. The beautiful snow melt stream showed evidence of flooding or erosion by its brown suspension load. The stream must get ferocious at times forming the large cut banks and point bars with whole trees being torn apart and carried with it. The snowmelt at the time was coming from the northern facing part of the valley still with snow patches visible in the warm air. We pass a small mining town of Jasper along the road and finally knew we were nearing the cabin.

Turning off of X Rd. onto a poorly managed road and to which the white van barely fit the sun started to set and night approached. Nate Henderson, the only person that has ever been to the cabin, but not in about 10 years, had only a faint idea of what the area looks like or where it remotely was. We drove around and hit a dead end and realized that we were not on the right road. We passed many possible turn offs and become uncertain of when or if we would even find the cabin. After trying a few other dead end roads and the white van getting harder and harder to maneuver in the dark, we started to debate whether it would be worth just stopping and pitching the tents where we were. Nate H. would not stand for it and wanted to try a few other options. The little minivan ended back on X Rd. and found another turn off that fortunately led us to the cabin to the delight of Ron, who had started to get a little sour about the whole ordeal.

Nathan’s dad graciously invited us to stay in a cabin that he and some friends built while they were in college during the ’70s. The story goes that he and his colleagues found some cheap land up in the mountains away from their college, Colorado College. They stole a cabin building book out of a public library and built the simple rustic cabin from scratch. The cabin is a single room equipped over the years with everything a cabin could have. It contained pots, pans, plate, utensils, most all the essential kitchen ware, and a stove in the corner of the eastern and southern wall, a dining room table with pictures of previous guests hanging above and an assortment of wooden and metal chairs in various conditions surrounding the table along the western wall, tool shed equipment (shovels, brooms, hoes, axes, hammers and a self full of nails and other metal objects) are hidden in a corner behind the door facing south and the western wall, a cot and deer skins hanging on the remaining northern wall. All but the north facing wall had a window most likely to keep out the chilling northern winds. Although a little crammed and dark as there is no electricity, the cabin has a special comfy homey feeling to it.

The excitement of finally finding the cabin caused everyone to jump out of the vans and walk over the knoll that keeps the cabin isolated and hidden. Nate’s father, Bunker, decided when he built the cabin that he did not want to have cars visible when sitting there and so one must walk about a hundred yards before getting to it. In the dark and excited after exploring a little we went back and retrieved our luggage.

May 16th, 2004 not only represented the day that we arrived at the wonderful cabin but also Andy Parker’s 11th birthday. That night we cooked brats and hotdogs for dinner around a fire pit east of the cabin. The environment of the group during the night was comfortable and close. Everyone played some part in the cooking of the brats and hot dogs with someone trying to cut the frozen brats in half, someone passing the brats to the cook and then someone doing the rotating of the brats. Following the main meat course, we brought out a crème cake and Andy’s birthday gifts so Andy would have more of an official birthday even though he was with his new older friends. I got the impression that the little guy was a little bit shy around us still but I think that birthday was a hit for all. After the cake, musical instruments came out. A couple of guitars played and rotated by Nate H., Gabe, Tim, and Ron proved to be the central entertainers with Tess bringing out her drum for beat. Others in the group joined into the music by hitting sticks on sticks, rocks on rocks, cans on cans, and hands on hands. Everyone seems to pull their weight and participate in the group making for a great group of people. The music played into the early morning and everyone enjoyed themselves.

   Geology
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