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TitreVariability of outcrop magnetic susceptibility and its relationship to the porphyry Cu centers in the Highland Valley Copper district
AuteurByrne, K; Lesage, G; Morris, W A; Enkin, R J; Gleeson, S A; Lee, R G
SourceOre Geology Reviews vol. 107, 2019 p. 201-217, https://doi.org/10.1016/j.oregeorev.2019.02.015
Année2019
Séries alt.Ressources naturelles Canada, Contribution externe 20180413
ÉditeurElsevier BV
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.1016/j.oregeorev.2019.02.015
Mediapapier; en ligne; numérique
Formatspdf (Adobe® Reader®)
ProvinceColombie-Britannique
SNRC92I/02NE; 92I/02NW; 92I/03NE; 92I/03NW; 92I/05; 92I/07; 92I/10; 92I/11; 92I/14SE; 92I/14SW; 92I/15SE; 92I/15SW
Lat/Long OENS-121.4167 -120.6667 50.9167 50.0000
Sujetsprospection minière; directives d'exploration; gisements minéraux; gisements porphyriques; cuivre porphyrique; minéralisation; genèse des minerais; gîtes minéralogiques; levés géophysiques; levés magnétiques, sol; susceptibilité magnétique; altération; propylitisation; séricitisation; auréoles d'altération; filons; géostatistiques; analyses statistiques; établissement de modèles; analyses de faciès; géologie du substratum rocheux; roches ignées; roches intrusives; granodiorites; monzogranites; diorites; roches intrusives mafiques; roches intrusives felsiques; brèches; stocks; roches volcaniques; andésites; intrusions; batholites; filons rocheux; roches hôtes; perméabilité; magmatisme; fluage; Batholite de Guichon Creek ; Terrane de Quesnel ; Groupe de Nicola ; affleurements; géologie économique; géophysique; géomathématique; Phanérozoïque; Mésozoïque; Trias
Illustrationsschematic representations; geoscientific sketch maps; tables; photographs; frequency distribution diagrams; plots; profiles; cumulative frequency diagrams; histograms
ProgrammeInitiative géoscientifique ciblée (IGC-5), Systèmes minéralisés - intrusions/porphyriques
Diffusé2019 02 14
Résumé(disponible en anglais seulement)
The Highland Valley Copper porphyry Cu-(Mo) centers compose Canada's largest porphyry Cu mining district, and are hosted in plutonic rocks of the Late Triassic Guichon Creek batholith in the Quesnel terrane, British Columbia. Here we evaluate the relationship between variations in magnetic susceptibility and alteration in order to define a footprint around the porphyry Cu centers using a district-scale dataset of 1610 minimally weathered outcrops and 11,432 magnetic susceptibility measurements. Statistical analysis of the outcrop-based measurements revealed changes in outcrop geometric mean magnetic susceptibility and the coefficient of variation (extent of variability in relation to the mean) are proportional to vein frequency and altered rock volume estimates. At a confidence interval of 95% and 9 degrees of freedom, the average standard error (uncertainty) of the geometric mean and coefficient of variation from 10 magnetic susceptibility outcrop measurements is 7.3% and 13.2%, respectively. Modeling of outcrop magnetic susceptibility data shows that domains of coefficient of variation of >0.3 extend 1-4 km away from the porphyry centers, whereas pronounced susceptibility lows of <10×1/1000 SI have a smaller footprint centered on the Cu-mineralization. The magnitude of change of magnetic susceptibility coefficient of variation between protolith and altered rocks in the porphyry Cu footprint is greater than the corresponding change in susceptibility geometric means. Thus, with some caveats, variability in magnetic susceptibility provides a good signal that corresponds to vein and alteration intensity, and can potentially be used to map ore-forming processes and to vector to porphyry Cu centers.
GEOSCAN ID313745