Natural Bridges

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Field Location: Natural Bridges National Monument and vicinity (White Canyon) (click on link to see photos)
Geologic Feature: Interfingering of Permian lacustrine or marine and continental strata at a 1-10 m scale. Interfingering of eolian and mudflat facies at a 1-100 m scale. Permian/Triassic unconformity; change from arid (eolian) to wetter conditions (mudflats, fluvial systems, paleosols, plant fossils, trace fossils).
Necessary Background Information: Permian/Triassic unconformity and potential causes. 
Geologic Problem: How are climate, sea level change, and tectonic activity reflected in these rocks? 
Rock Units Exposed: Permian Cedar Mesa Sandstone, Organ Rock Formation, and White Rim Sandstone. Triassic Moenkopi and Chinle Formations.
Skills: Documenting depositional environments. Identifying fossils and trace fossils.
Other Questions to Consider: (1) What are the differences between water-deposited and wind-deposited sediments? (2) What timescales are involved in depositing various thicknesses of materials by different mechanisms? (3) What magnitude of climate change is necessary to cause such drastic changes in depositional conditions? (4) What types of creatures lived in these environments? (5) What characteristics of plants can be linked to their environments?
Anticipated Outcomes: Differentiation among marine, transitional, and freshwater environments. Physical description and analysis of fossils. Ability to “create a story” from field (i.e., restricted sampling) evidence.