Abstract

This work may have a narrow geographic focus, namely a handful of steep and densely forested valleys of the Southern Italian Alps, but its scientific goals are certainly wide. Through a combined analyses of the spatial distribution, geochemical characteristics and temporal duration of the Permian silicic magmatism in the renown Ivrea crustal section (Sesia Magmatic System), this dissertation addresses fundamental questions regarding the physical mechanisms of rhyolitic magma storage, mobilization and eruption.

A brief introduction serves to define the broader context of the scientific questions addressed in the three main chapters of this dissertation. Through Chapters 2 to 4 we apply a set of petrologic, and geochronologic techniques to the intrusive and volcanic products of a transcrustal magmatic system. These constrains provide the image of a long-lived (~ 1 Myr), crystalline rhyolitic magma body residing at upper crustal conditions (400 to 200 kbar), episodically replenished by magmas of variable compositions. This magmatic reservoir was a dynamic environment were the active separation of solid and liquid phase helped create a thick cap of potentially eruptible rhyolitic material. We utilize this uniquely exposed system to test the consistency of models of magma chamber assembly and evolution developed solely in volcanic environment or through numerical modeling. Ultimately, we indicate that the plutonic record can document physical processes and timescales usually associated with volcanic processes, opening a new chapter in the volcanic-plutonic connection book.

Degree Date

Fall 2021

Document Type

Dissertation

Degree Name

Ph.D.

Department

Roy M. Huffington Department of Earth Sciences

Advisor

Rita C. Economos

Second Advisor

Robert T. Gregory

Third Advisor

James E. Quick

Fourth Advisor

Crayton J. Yapp

Fifth Advisor

Olivier Bachmann

Subject Area

Earth, Atmospheric and Marine Sciences, Physical Sciences

Number of Pages

222

Format

.pdf

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

Available for download on Sunday, December 10, 2023

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