Petrographic and strontium isotope analysis on rare earth element bearing minerals in Hicks Dome, Southern Illinois

Yu, Mingyue

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https://hdl.handle.net/2142/120166 Copy

Description

Title

Petrographic and strontium isotope analysis on rare earth element bearing minerals in Hicks Dome, Southern Illinois

Author(s)

Yu, Mingyue

Issue Date

2023-05-04

Director of Research (if dissertation) or Advisor (if thesis)

• Lundstrom, Craig C
• Trela, Jarek

Department of Study

Earth Sci & Environmental Chng

Discipline

Geology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Rare Earth Elements
• Hicks Dome
• Petrography
• Sr Isotope

Abstract

Rare Earth Elements (REEs) are often referred to as ‘the vitamins of modern industry’, for their omnipresence in almost all high-tech manufacturing. From electrical vehicles to wind turbines, Rare Earth Elements play a critical role in changing the amount of global carbon emission and serve as a crucial part of transforming our society to a carbon neutral future. However, for the past few decades, the United States has imported over 90% of its REE from foreign countries. The recent developments in international politics and global supply chain crisis have posed serious challenges for the stability of REE supply for U.S. industries. Hicks Dome, a volcanic structural dome located in Southern Illinois, represents a proven domestic source of REEs. Samples for this thesis were collected from drill cores drilled at Hicks Dome and at adjacent igneous structures in the Permian Wauboukigou Igneous Province (PWIP). These samples trend toward high CaO (>30 wt%) and low SiO (<10 wt%). These four samples demonstrate elevated REEs (>1000 times chondrite) and show significant Light REE (LREE) or Heavy REE (HREE) enrichment were selected for petrographic and isotopic analysis. EDS and XRD analysis show Xenotime (Y) and Monazite are the major REE-bearing minerals and Florencite, Bastnäsite, and Bertrandite are the minor REE-bearing minerals in these samples. The age corrected 87Sr/86Sr for the samples that are enriched in HREE have a radiogenic signature of 0.70801-0.70829, and LREE enriched sample has a complex but lower average range of 0.70404-0.70724. The Sr isotope ratios reveals crustal mixing with the igneous source in Hicks Dome and adjacent areas. The Sr ratios from the LREE enriched samples show similarity to other igneous features in the region and cannot rule out the possibility of a uniform origin of these two types of samples. The Sr ratio of 0.70404 indicates a primitive to mild integration of magma with the in-situ sedimentary rocks, while the Sr ratio of 0.70829 demonstrates a more extensive mixing of the dominant sedimentary signature, with only a very limited presence of primitive material.

Graduation Semester

2023-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Mingyue Yu

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