Dinosaur National Monument Trip, Summer 2007

Professors Clay Kelly and Basil Tikoff led a field trip to Dinosaur National Monument (UT, CO) in the summer of 2007.

The trip lasted approximately 10 days and included stops at numerous points of geologic interest in the states of Colorado, Utah, and Wyoming enroute to and from Dinosaur National Monument (DNM).  This trip was a culmination of spring-semester class (Geology & Paleontology of DNM) that covered a wide variety of geological disciplines including: (1) regional tectonic history, (2) structural geology, (3) stratigraphy and sedimentology, and (4) invertebrate and vertebrate paleontology.

The picturesque landscape and spectacular geology of Dinosaur National Monument (DNM) in Utah and Colorado was the focal point of a collaborative and interdisciplinary field trip led by geology faculty from UW-Madison (Clay Kelly and Basil Tikoff) and UW-Milwaukee (Dyanna Czeck, Stephen Dornbus, and Margaret Fraiser) in June 2007. Eleven GeoBadger students went along on this ten-day-long road trip, which was the culmination of a seminar class from the previous spring semester.

Tee Pee Buttes
Stop #1: Teepee Buttes

As indicated by its name, DNM is best known for its unique museum that showcases one of the richest Jurassic-aged dinosaur bone beds in the world. Equally impressive are the monument’s many panoramic vistas that afford geologists a bird’s eye view of a sedimentary sequence that spans much of the Phanerozoic Era as well as classic Laramide structures related to the uplift of the Uinta Mountains. The combined forces of fluvial erosion and tectonic uplift have dissected the region, making it a wonderful outdoor classroom where students received hands-on instruction about various aspects of paleontology, structural geology, stratigraphy, and sedimentation.

The trip also included stops and roadside lectures at numerous points of geologic interest enroute to and from DNM. The first stop was at Red Rocks Amphitheatre just outside Denver, CO where we stretched our legs by climbing around on the Pennsylvanian-aged Fountain Formation, which consists of alluvial fan and braided stream deposits that formed from the drainage of the Ancestral Rockies. This steeply dipping, arkosic sandstone unit is juxtaposed directly against Precambrian gneisses and granites in a beautifully exposed unconformity. We also hiked through the local Mesozoic section, which contains numerous dinosaur bones and tracks as well as a wide variety of sedimentary structures. Then, we raced back to the van before a whopper of a thunderstorm hit. We are not sure how we managed it, but we stayed relatively dry that night. The second stop was just south of Pueblo, CO where we visited Teepee Buttes.

Tee Pee Buttes
A Teepee mound structure

These carbonate (limestone) mounds form isolated promontories that dot the countryside. The bizarre invertebrate fossils clustered atop these mounds are thought to represent chemosynthetic communities associated with ancient methane seep sites on the Cretaceous seafloor (Basil’s interpretation of this last sentence: The critters were living in a pile and eating methane).

We then drove through the metamorphosed Proterozoic rocks of the Wet Mountains on our way to the Black Canyon of the Gunnison, CO. This impressive chasm exposes a Protererozoic shear zone that has been intruded by numerous felsic dikes. In typical field trip fashion, we visited the stores and then camped in the pitch black at Colorado National Monument. The next morning, braving road construction, we spent time hiking through ancient (Mesozoic) dune fields deposited atop Proterozoic basement within the Ancestral Rockies’ Uncompahgre Uplift. We then visited a famous Marsh dinosaur site just outside the monument and spent an hour visiting the Morrison formation.

Gunnison River in Colorado
Stop #2: Pinnacle formations along the Gunnison River in Colorado.

On our way north, we visited the Douglas Creek Arch (the structural geologists were amazed by how long paleontologists can look at flat-lying, undeformed shales under very, very windy conditions). That night, we arrived at our destination of Dinosaur National Park in Utah (having provisioned the night before in Colorado).

The following days, we spent time exploring the monument area and hiking out to several of its famous overlooks. We only had a blizzard (in May) at the best overlook—the rest of the time it was merely raining or threatening to.

Stop #3: Triassic-Jurassic eolian sandstones

This gave students an opportunity to see (or imagine, in the case of the blizzard) firsthand the rock units and many geologic structures (monoclines, anticlines, synclines, faults) we had discussed in class during the previous semester. However, the highlight of the entire trip was a daylong rafting trip down the Green River (it rained, but who cares when you’re shooting rapids). The Green River flows directly through the core of Split Mountain Anticline, so students enjoyed the thrill of whitewater rafting as they drifted through the monument’s Paleozoic stratigraphy. There’s simply no better way to experience the geology of this rugged landscape.

After our stay in DNM, we headed north toward the Green River Basin in Wyoming. Along the way we stopped to see such famous points of geologic interest as the Sparks Fault Nappe in Sheep Creek Canyon (Utah) and Flaming Gorge.

The Green River
Rafting along the Green River

We spent the next couple of days being led by Alan Carroll, who gave us an overview of the stratigraphy and tectonic history of the Green River Basin. Our final stop was at Westphal Dinosaur Quarry located in Bighorn Basin, Wyoming. Here, Joe Skulan of the UW-Madison Geology Museum gave an impromptu lecture about the paleontology and stratigraphy of the dig site.

Westphal Quarry
Stop #7: Westphal Quarry

Students spent most of that afternoon collecting marine invertebrate fossils from the nearby Sundance Formation (Jurassic). The field trip was an overall success and all parties involved learned a great deal from one another (including, always bring your raincoat and a wool hat).

We particularly enjoyed the interaction with the UW-Milwaukee folks and hope to have more shared trips in the future. It is this type of group experience that both students and faculty, having survived the weather, look back upon with fond memories.

The field trip was supported in part by Chevron and the Student Field Experience Fund.

Originally published in The Outcrop for 2007, UW-Madison Department of Geology and Geophysics, p. 13.