Research Mentor(s)
Stelling, Peter L.
Description
Crystals found within geothermal cores from Akutan Island, Alaska, show concentric growth rings of what appear to be alternating bands of epidote and clinozoisite minerals. The intent of this project is to determine the nature of these growth rings and what processes could allow them to form. Our working hypothesis is that the rings are due to fluctuations in the oxidation states of the hydrothermal system, which would control the amount of available Fe3+ needed to make epidote. In relatively reducing conditions, Fe3+ would be scarce and clinozoisite (Fe-poor variety of epidote) would form. We have tested this hypothesis by chemically mapping the zoned minerals with the Energy Dispersive Spectrometer (EDS) on the Scanning Electron Microscope (SEM) at WUU and using the electron microprobe at U-Washington to collect precise compositional data. If our hypothesis is correct, this will tell us how water flows in this system and how rapidly mineral-forming conditions can fluctuate and the nature of mineral formation in hydrothermal systems.
Document Type
Event
Start Date
17-5-2017 12:00 PM
End Date
17-5-2017 3:00 PM
Department
Geology
Genre/Form
student projects; posters
Subjects – Topical (LCSH)
Geothermal resources--Alaska--Akutan Island; Hydrothermal deposits--Alaska--Akutan Island
Geographic Coverage
Akutan Island (Alaska)
Type
Image
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this documentation for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Language
English
Format
application/pdf
Included in
Analysis of Concentric Growth Rings in Hydrothermal Epidote
Crystals found within geothermal cores from Akutan Island, Alaska, show concentric growth rings of what appear to be alternating bands of epidote and clinozoisite minerals. The intent of this project is to determine the nature of these growth rings and what processes could allow them to form. Our working hypothesis is that the rings are due to fluctuations in the oxidation states of the hydrothermal system, which would control the amount of available Fe3+ needed to make epidote. In relatively reducing conditions, Fe3+ would be scarce and clinozoisite (Fe-poor variety of epidote) would form. We have tested this hypothesis by chemically mapping the zoned minerals with the Energy Dispersive Spectrometer (EDS) on the Scanning Electron Microscope (SEM) at WUU and using the electron microprobe at U-Washington to collect precise compositional data. If our hypothesis is correct, this will tell us how water flows in this system and how rapidly mineral-forming conditions can fluctuate and the nature of mineral formation in hydrothermal systems.
Comments
Outstanding Poster Award Recipient