| Titre | Elucidating mineralizing fluid pathways from the geophysical responses to hydrothermal alteration: integrated 3D modelling of lithogeochemical, petrophysical, seismic and magnetotelluric data, Lalor
volcanogenic massive sulphide deposit, Manitoba |
| Télécharger | Téléchargement (publication entière) |
| Auteur | Schetselaar, E M; Bellefleur, G; Craven, J A; Ansari, S M; Enkin, R J |
| Source | Targeted Geoscience Initiative: 2017 report of activities, volume 1; par Rogers, N (éd.); Commission géologique du Canada, Dossier public 8358, 2018 p. 229-242, https://doi.org/10.4095/306479 (Accès ouvert) |
| Année | 2018 |
| Éditeur | Ressources naturelles Canada |
| Document | dossier public |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/306479 |
| Media | en ligne; numérique |
| Référence reliée | Cette publication est contenue dans Rogers, N;
(2018). Targeted Geoscience Initiative: 2017 report of activities, volume 1, Commission géologique du Canada, Dossier public 8358 |
| Formats | pdf |
| Province | Manitoba |
| SNRC | 63N/16 |
| Lat/Long OENS | -100.2000 -100.1000 54.9000 54.8500 |
| Sujets | gisements minéraux; prospection minière; potentiel minier; établissement de modèles; contrôles des minerais; genèse des minerais; minéralisation; métaux de base; gîtes volcanogènes; gîtes sulfureux; zinc;
système hydrothermal; altération hydrothermale; fluage; dynamique des fluides; lithogéochimie; levés géophysiques; interpretations sismiques; ondes sismiques; ondes P; levés de reflexion sismiques; pétrophysique; interprétations magnétotelluriques;
conductivité; champs électromagnétiques; géochimie des roches totales; analyses statistiques; régressions statistiques; analyses de carottes de sondage; géologie du substratum rocheux; lithologie; roches ignées; roches intrusives; roches intrusives
mafiques; gabbros; diorites; granodiorites; tonalites; granites; roches ultramafiques; roches volcaniques; volcanoclastique; tufs volcaniques; rhyolites; dacites; coulées de lave; brèches; basaltes; andésites; rhyodacites; caractéristiques
structurales; failles; failles, chevauchement; Archéen; Orogenèse de Trans-hudson ; Craton de Sask ; géologie économique; géochimie; géophysique; géologie structurale; pétrologie ignée et métamorphique; Précambrien; Protérozoïque |
| Illustrations | geoscientific sketch maps; plots; 3-D images; tables; 3-D models; models; cross-sections; graphs |
| Consultation | |
| Bibliothèque de Ressources naturelles Canada - Ottawa (Sciences de la Terre) |
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| Programme | Gestion de la connaissance de IGC, Initiative géoscientifique ciblée (IGC-5) |
| Programme | Systèmes volcaniques et sédimentaires, Initiative géoscientifique ciblée (IGC-5) |
| Diffusé | 2018 01 19 |
| Résumé | (disponible en anglais seulement)
This research activity aims a developing a better understanding of the geophysical response of hydrothermally-altered rocks associated with volcanogenic massive
sulphide (VMS) deposits. Integrated modelling of physical rock property, whole rock geochemistry and 3D seismic data from the Lalor VMS deposit, Snow Lake, Manitoba enhanced insight into the seismic responses of hydrothermally-altered rocks in the
footwall of the massive sulphide ore zone. Multivariate regression of P-wave velocity and density on lithogeochemical proxies for protolith composition, mineralization and hydrothermal alteration suggests that hydrothermal alteration in the footwall
of the Lalor deposit enhanced acoustic impedance contrast between mafic to felsic volcanic units. Compositional variations between mafic, intermediate and felsic volcanic rocks, as modelled by the log(Zr/TiO2) immobile element ratio, remains the
predominant factor that controls seismic response, independent from the intensity of hydrothermal alteration. The results obtained from the multivariate regression model are further corroborated by seismic forward modelling experiments, yielding
enhanced seismic reflectivity in the intensely-altered footwall when alteration proxies are included in the 3D seismic rock property models. In parallel, geophysical response modelling of magnetotelluric (MT) data will be developed based on forward
and inverse modelling routines on tetrahedral meshes, which yield results that are compatible with the general geological structure of the deposit. Initial unconstrained 3D MT inversions show a conductive zone between 600 to 800 m depth corresponding
to the Lalor deposit, as well as, a highly conductive zone between depths of 500 to 1500 m, about 0.5 to 1.2 km to the southwest of the deposit. |
| GEOSCAN ID | 306479 |
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