Files and links (1)
CC BY-NC-ND V4.0, Open Access
Thesis
Cl/Br in scapolite as a tracer for fluid sources and evolution in the Mesoproterozoic Belt Supergroup
Washington State University
Master of Science (MS), Washington State University
2023
DOI:
https://doi.org/10.7273/000005037
Abstract
The behavior of halogens during metamorphic processes directly impacts and controls a range of first-order geological processes, such as mass transfer (including ore formation) or the composition of the atmosphere. However, while the release of halogens into the atmosphere during metamorphic events is believed to be directly linked to global warming and mass extinction events and the formation of certain types of ore deposit are thought to be governed by halogen-bearing metamorphic fluids, the fundamental behavior of halogens during metamorphic processes is poorly understood. To learn more about the behavior of the halogens Cl and Br during metamorphism, this research uses scapolite-group minerals as archives for Cl and Br behavior during thermal events in scapolite-bearing metasedimentary rocks of the Mesoproterozoic Belt Supergroup, USA. Scapolite-group minerals can sequester halogens (Cl, Br, I), CO2, and SO4 that were present in its protolith host and/or in fluids that interacted with the host unit. Based on halogen ratios of scapolite fluid sources in the crust can be determined (e.g., evaporitic vs. residual bittern brine vs. magmatic). Combined EPMA and LAICPMS analyses are used to reconstruct the fluid sources and evolution in several metamorphic units of the Belt Supergroup. The collected data show evidence for the presence of halite dissolution fluids across all metamorphic grades within the Wallace Formation and lower Missoula Group of the larger Belt Supergroup. However, in other parts of the metamorphic belt, residual dense bittern brine fluids circulated during metamorphic events, and may have been critical for the formation of some of the Co mineralization in the Idaho cobalt belt.
Metrics
6 File views/ downloads
41 Record Views
Details
- Title
- Cl/Br in scapolite as a tracer for fluid sources and evolution in the Mesoproterozoic Belt Supergroup
- Creators
- Isabelle Rein
- Contributors
- Johannes Haemmerli (Advisor)Scott Boroughs (Committee Member)Reed Lewis (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- School of the Environment (CAHNRS)
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Number of pages
- 266
- Identifiers
- 99901019834501842
- Language
- English
- Resource Type
- Thesis