Date of Graduation
7-2026
Document Type
Thesis
Degree Name
Master of Science in Geology (MS)
Degree Level
Graduate
Department
Geosciences
Advisor/Mentor
Dumond, Gregory
Committee Member
Potra, Adriana
Second Committee Member
Shaulis, Barry
Keywords
Athabasca Granulite Terrane; Garnet; Geochronology; Mafic Granulite; MC-ICPMS; Whole Rock Geochemistry
Abstract
The Athabasca granulite terrane in the western Canadian Shield (AGT) with felsic and mafic granulites preserves depths of 20-60km and temperatures as high as 900°C. The felsic material has been dated at 2.6 Ga and 1.9 Ga using high precisions ID-TIMS zircon 207Pb/206Pb dates and monazite growth patterns analyzed using in situ electron probe microanalysis; the mafic material is not well dated. Six mafic granulites were dated using the 176Lu/177Hf and 147Sm/143Nd dating system with garnets pared with trace element mapping. Using a multi-collector inductively coupled plasma mass spectrometer (MC-ICPMS), the 176Lu/177Hf data collected from six different samples at various depths along the AGT indicate crystallization dates at around 2.1 Ga. The 147Sm/143Nd dates of the same six samples indicate a cooling date at 1.9 Ga. The dates collected are inconsistent with the known dates of tectonic events. The diffusion of trace elements in garnets could clarify the inconsistency, indicating artificially high or low results for 176Lu/177Hf, so trace element mapping was carried out for 6 garnets looking primarily at Lu175 and Cr52.
Citation
McClintock, G. (2026). Mafic Granulite Garnet Geochronology in the Deepest Section of the Athabasca Granulite Terrane. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/6400
A.2_GarnetComposition.xlsx (46 kB)
A.3_TraceElementAnalyses.xlsx (35 kB)
A.4_GarnetGeochronology.xlsx (18 kB)
