U-Pb and Lu-Hf LA-ICP-MS detrital zircon and structural investigations in the Abitibi subprovince, Canada, with implications for Archean geodynamic processes and deformation behavior along gold-bearing, crustal-scale faults
dc.contributor.advisor | Kuiper, Yvette D. | |
dc.contributor.author | Frieman, Ben M. | |
dc.date.accessioned | 2018-05-11T20:31:43Z | |
dc.date.accessioned | 2022-02-03T13:11:19Z | |
dc.date.available | 2018-11-09T20:31:43Z | |
dc.date.available | 2022-02-03T13:11:19Z | |
dc.date.issued | 2018 | |
dc.identifier | Frieman_mines_0052E_11468.pdf | |
dc.identifier | T 8467 | |
dc.identifier.uri | https://hdl.handle.net/11124/172262 | |
dc.description | Includes bibliographical references. | |
dc.description | 2018 Spring. | |
dc.description.abstract | This work presents investigations based in the south-central Abitibi subprovince of Ontario and Quebec, Canada, which place constraints on a sequence of Neoarchean geodynamic and structural processes, including crustal growth and amalgamation with the rest of the Superior Province, and the formation of orogenic gold deposits along regional deformation zones. Archean geodynamic processes were primarily investigated by multi-isotope U-Pb and Lu-Hf laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) analysis of detrital zircon grains from successor basins. Three temporally distinct successor basin groups are recognized: the ~2690-2685 Ma Porcupine assemblage, the ~2685-2682 Ma Pontiac subprovince, and the ~2680-2670 Ma Timiskaming assemblage. All samples contain abundant Neoarchean grains (~85-95% of the individual sample populations), while the remaining grains yielded Mesoarchean ages. The Neoarchean grains likely reflect predominately local sources. Since no Mesoarchean rocks occur in the Abitibi and Pontiac subprovinces, and based on comparison with published zircon ages from the Superior Province, Mesoarchean grains are interpreted as derived from an orogenic hinterland to the NNW that developed during regional amalgamation. The older Porcupine assemblage contains ~5% Mesoarchean zircon, while Pontiac subprovince and Timiskaming assemblage samples contain ~18% and ~13%, respectively. This suggests hinterland sources were more prevalent during the late stages of collision, probably as a result of progressive uplift and denudation of the hinterland. The paired Lu-Hf isotopic analyses support this interpretation of provenance and further indicate that the majority of grains (~96%) have compositions consistent with derivation from a modern MORB depleted mantle (mMORB-DM) reservoir. This occurrence of mMORB-DM-like signatures in detrital zircon grains that were sourced from multiple disparate crustal domains suggests that a modern-style depleted mantle reservoir was not only well established, but widely occurring by the Mesoarchean. The observed pattern of lateral accretion of crustal domains that grew from a mMORB-DM-like reservoir, the transport of detritus across terrane boundaries, and the progressive uplift and denudation of a hinterland are most consistent with the operation of plate tectonic processes during Neoarchean construction and amalgamation of the southern Superior Province. During the late stages of accretion, deformation became increasingly localized along regionally extensive, crustal-scale fault zones, including the Larder Lake Cadillac deformation zone (LLCdz) in the Kirkland Lake area of Ontario. New field mapping and map compilation indicates that a series of spaced brittle-ductile deformation zones occur in a broad, >6 km area to the north of the LLCdz. Detailed structural mapping and analysis further indicate that the location of late-stage brittle-ductile deformation, fluid flow, and gold mineralization was likely controlled by early brittle deformation zones characterized by breccia. Therefore, undiscovered gold deposits may be hosted by deformation zones farther from the LLCdz than previously recognized and that fault-related breccia bodies may provide an indicator for nearby prospective structures in both the Kirkland Lake area and in similar structural settings of all ages, worldwide. | |
dc.format.medium | born digital | |
dc.format.medium | doctoral dissertations | |
dc.language | English | |
dc.language.iso | eng | |
dc.publisher | Colorado School of Mines. Arthur Lakes Library | |
dc.relation.ispartof | 2010-2019 - Mines Theses & Dissertations | |
dc.rights | Copyright of the original work is retained by the author. | |
dc.subject | Archean plate tectonics | |
dc.subject | depleted mantle | |
dc.subject | provenance | |
dc.subject | brittle-ductile localization | |
dc.subject | Archean greenstone belts | |
dc.subject | orogenic gold | |
dc.title | U-Pb and Lu-Hf LA-ICP-MS detrital zircon and structural investigations in the Abitibi subprovince, Canada, with implications for Archean geodynamic processes and deformation behavior along gold-bearing, crustal-scale faults | |
dc.type | Text | |
dc.contributor.committeemember | Monecke, Thomas | |
dc.contributor.committeemember | Kelly, Nigel | |
dc.contributor.committeemember | Andrews-Hanna, Jeffrey C. | |
dcterms.embargo.terms | 2018-11-09 | |
dcterms.embargo.expires | 2018-11-09 | |
thesis.degree.name | Doctor of Philosophy (Ph.D.) | |
thesis.degree.level | Doctoral | |
thesis.degree.discipline | Geology and Geological Engineering | |
thesis.degree.grantor | Colorado School of Mines | |
dc.rights.access | Embargo Expires: 11/09/2018 |