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Field Location: Dinosaur National Monument (click
on link to see photos).
Geologic Feature: Tilted strata along the north side of Split
Mountain.
Necessary Background Information: Stratigraphy of Dinosaur National
Park.
Geologic Problem: Construct a geologic map of formations encountered
along the Desert Voices and Sounds of Silence nature trails.
Rock Units Exposed: Permian Weber Sandstone to Cretaceous Frontier
Formation.
Skills: Identification of different geologic formations in the field.
Use of a Brunton to take attitudes of bedding and paleocurrent directions.
Ability to accurately determine and plot locations on a map.
Other Questions to Consider: 1) How does the nature trail's course
relate to the geology of the area? Did the trail planners consider the
geology when building this trail? 2) Try to use both triangulation and pacing
to determine your location today. Which method is faster for you? Which is
easier? 3) What characteristics of the rock units encountered make it
possible to distinguish them? 3) How do the formations change orientation as
you move away from Split Mountain? Take at least 2 strike and dip
measurements within each formation so that you can answer this question. 4)
The instructors and T.A.s will be stationed along the trail at sites where
exceptional features are present, and will help you describe and interpret
the features. What sort of paleocurrent indicators do you see today? Where in
modern environments do these features form? 5) After you complete your
geologic cross section, can you make any estimate of how old Split Mountain
must be? 6) How did the climate in the Dinosaur area change through time? How
did it differ from the climate in the Canyonlands region? 7) Was this area
closer or farther from the sea during the Pennsylvanian and Permian than the
Canyonlands and Capitol Reef areas? 8) Why are dinosaur bones preserved
here? What processes lead to the preservation of bones versus trackways?
Anticipated Outcomes: Use of topographic maps and Brunton compasses to
determine location. Use of Brunton compasses to take strikes and dips.
Identification of sedimentary structures. Paleocurrent measurements.
Identification of contacts. Identification of different sedimentary rock
types. Recognition of products of different depositional environments.
Geologic map preparation. Cross section construction. Understanding the
mechanisms of fossilization.
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