Document Type and Release Option
Thesis (open access)
Dr Robert Kelly Vance
Rare earth elements (REEs) are important resources with applications in the electronics, renewable energy, and automotive industries. REEs may be concentrated in the residual weathered portion of igneous parent rocks, typically granites. These residual deposits are mined in southeast Asia, but analogous climatic and geologic conditions suggest the existence of economically viable REE residual deposits in the southeastern United States (U.S.). The Sparta Granite Complex in east-central Georgia is a granitoid complex emplaced at the end of the Alleghanian orogeny, forming a suture between the Savannah River and Milledgeville terranes. Petrologic and geochemical assessments of the Sparta Granite and overlying in situ residual deposits elucidate its intrusive history and explore the potential to produce economically significant residual REE deposits. Fresh rock and saprolite were obtained from two aggregate quarries near Sparta, Georgia and one aggregate quarry near Warrenton, Georgia. Field observations of flow brecciation and multiple granitic phases including pegmatitic and aplite dikes indicate significant fractionation. Thin section analysis showed deformation features and strain indicators in feldspars and quartz suggesting a late-kinematic formation. Accessory minerals include zircon, sphene, apatite, and partially to fully metamict allanite. Geochemical data of representative rock samples and saprolite are acquired with inductively coupled plasma mass spectrometry (IC-PMS) and indicated a volcanic arc origin with possible crustal contamination. Major REE sources were garnet and zircon for HREE and allanite, sphene, and apatite for LREE.
Eshbaugh, Max J., "Petrological and Geochemical Evaluation of Rare-Earth Element Potential in the Sparta Granite Complex" (2023). Honors College Theses. 893.