The Gunlock Member: Describing a New Member of the Carmel Formation (Middle Jurassic) of Southwestern Utah

Lucie Fiala head shot

Name: Lucie Fiala
Major: Environmental Geoscience
Minor: Spanish
Advisor: Mark Wilson

The Carmel Formation spans across much of the western United States. It is composed of several members, or layers, of rock that overlie each other based on geologic time. The lowest of the members, currently called the Co-op Creek Member, is from the Middle Jurassic (Bajocian, ~170 mya) and consists of two units with different lithologies; that is, the units have different rock compositions. Due to their distinct lithologies they should be designated as separate members. This study aims to describe and analyze samples taken from both units and rename the lower to the Gunlock Member, while maintaining the upper as the Co-op Creek Member.

The divide between the members is indicative of a rise in sea level during the Middle Jurassic with an unknown cause. There are currently several studies on sea level rise and fall in the Jurassic worldwide, but it has been determined that the most likely cause of the rise that changed the lithology of the Co-op Creek Member and proposed Gunlock Member was due to a deglaciation caused by temperature fluctuations. This theory is supported by the analysis of ancient ocean cores and paleosols, or ancient soils.

This project aims to investigate lithologies and their attributes due to their depositional environments. The cause of the change in lithology was likely a deglaciation, which has recently become the subject of more study in this area in the Jurassic. I am passionate about glaciology and paleoclimatology and aim to continue my research on ice and climate in the future.

Posted in Comments Enabled, Independent Study, Symposium 2023 on April 14, 2023.

3 responses to “The Gunlock Member: Describing a New Member of the Carmel Formation (Middle Jurassic) of Southwestern Utah”

  1. Meagen Pollock says:

    What a cool link to your interests in glaciology. Well done, Lucie!

  2. Shelley Judge says:

    Great job, Lucie. I had such fun with you (and the other members of Team Utah) in the field in SW Utah, hiking within the Carmel and investigating all its cool characteristics.

  3. Prof. Leiby says:

    Congratulations, Lucie! It’s so great to see the amazing work you’ve done 🙂

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Language, histories, literature, and cultures of Spanish-speaking countries

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