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Crustal-scale geology and fault geometry along the gold-endowed Matheson transect of the Abitibi greenstone belt
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SYSNO ASEP 0544275 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Crustal-scale geology and fault geometry along the gold-endowed Matheson transect of the Abitibi greenstone belt Author(s) Haugaard, R. (CA)
Della Justina, F. (CA)
Roots, E. A. (CA)
Cheraghi, S. (CA)
Vayavur, R. (CA)
Hill, Graham J. (GFU-E) ORCID
Snyder, D. B. (CA)
Ayer, J. (CA)
Naghizadeh, M. (CA)
Smith, R. S. (CA)Source Title Economic Geology. - : Society of Economic Geologists - ISSN 0361-0128
Roč. 116, č. 5 (2021), s. 1053-1072Number of pages 20 s. Publication form Print - P Language eng - English Country US - United States Keywords lower continental crust ; electrical conductivity ; Southeastern Superior Subject RIV DB - Geology ; Mineralogy OECD category Geology Method of publishing Limited access Institutional support GFU-E - RVO:67985530 UT WOS 000656493900001 EID SCOPUS 85107918677 DOI 10.5382/econgeo.4813 Annotation Gold in the Abitibi greenstone belt in the Superior craton, the most prolific gold-producing greenstone terrane in the world, comes largely from complex orogenic mineralizing systems related to deep crustal deformation zones. In order to get a better understanding of these systems, we therefore combined new magnetic, gravity, seismic, and magnetotelluric data with stratigraphic and structural observations along a transect in the Matheson area of the Abitibi greenstone belt to constrain large-scale geologic models of the Archean crust. A high-resolution seismic transect reveals that the well-known Porcupine Destor fault dips shallowly to the south, whereas the Pipestone fault dips steeply to the north. Facing directions and gravity models indicate that these faults are thrust faults where older mafic volcanic rocks overlie a younger sedimentary basin. The depth of the basin reaches similar to 2 to 2.5 km between these two faults, where it is interpreted to overlie mafic-dominated volcanic substrata. Regional seismic and magnetotelluric surveys image the full crust down to 36-km depth to reveal a heterogeneous architecture. The significant resistivity transition between upper and middle crust is interpreted to be the result of interconnected micrographite grain coating, precipitated from carbon-bearing crustal fluids emplaced during Neoarchean craton stabilization. A major subvertical, seismically transparent, and extremely low resistive (<10 Omega m) corridor connects the lower and middle crust with the upper crust. The geometry of this low-resistivity feature supports its interpretation as a deep-rooted extensional fault system where the corridor acted as a regional-scale conduit for gold-bearing hydrothermal fluids from a ductile source region in the lower crust to the depositional site in the brittle upper crust. We propose that this newly discovered whole crustal corridor focused the hydrothermal fluids into the Porcupine Destor fault in the Matheson region. Workplace Geophysical Institute Contact Hana Krejzlíková, kniha@ig.cas.cz, Tel.: 267 103 028 Year of Publishing 2022 Electronic address https://pubs.geoscienceworld.org/segweb/economicgeology/article-abstract/116/5/1053/594206/Crustal-Scale-Geology-and-Fault-Geometry-Along-the?redirectedFrom=fulltext
Number of the records: 1