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TitreIntegration of rock properties and geophysics, Bathurst Mining Camp
TéléchargerTéléchargement (publication entière)
AuteurTschirhart, P A; Morris, W A
SourceTargeted Geoscience Initiative 4: Contributions to the understanding of volcanogenic massive sulphide deposit genesis and exploration methods development; par Peter, J M (éd.); Mercier-Langevin, P (éd.); Commission géologique du Canada, Dossier public 7853, 2015 p. 101-115,
ÉditeurRessources naturelles Canada
Documentdossier public
Mediaen ligne; numérique
Référence reliéeCette publication est contenue dans Peter, J M; Mercier-Langevin, P; (2015). Targeted Geoscience Initiative 4: Contributions to the understanding of volcanogenic massive sulphide deposit genesis and exploration methods development, Commission géologique du Canada, Dossier public 7853
SNRC21O/01; 21O/02; 21O/03; 21O/06; 21O/07; 21O/08; 21O/09; 21O/10; 21O/11; 21P/04; 21P/05; 21P/12
Lat/Long OENS -66.5833 -65.7500 47.7500 47.1333
Sujetsanalyse par spectromètre de masse; minéralisation; zinc; cuivre; plomb; or; argent; gîtes volcanogènes; gîtes sulfureux; densités; susceptibilité magnétique; interprétations géophysiques; Camp minier de Bathurst; géologie économique; géophysique; Paléozoïque; Ordovicien
Illustrationslocation maps; tables; plots; images
ProgrammeÉtude des gîtes de sulfures massifs volcaniques, Initiative géoscientifique ciblée (IGC-4)
LiensCanadian Database of Geochemical Surveys, downloadable files
LiensBanque de données de levés géochimiques du Canada, fichiers téléchargeables
Diffusé2015 06 11
Résumé(disponible en anglais seulement)
Physical rock property information is an important aspect of geophysical processing and interpretation as it provides a direct link between geophysical data and geological interpretations. Herein, the existing physical rock property (density and magnetic susceptibility measurements) database for host rocks and volcanogenic massive sulphide (VMS) mineralization in the Bathurst Mining Camp (BMC), northern New Brunswick, is expanded by incorporating new measurements taken on in situ samples and drill cores from throughout the BMC. Descriptive statistics are calculated and presented, and density-magnetic susceptibility bivariate plots are used to illustrate patterns indicative of changes in the abundances of paramagnetic versus ferrimagnetic mineral phases. A discrete object magnetic inversion, solving for the remanent magnetization vector of the Armstrong B anomaly, is computed. The inversion is constrained geometrically by geological mapping at surface and diamond drilling at depth. Magnetic susceptibility values for the country rock and mineralization are from the physical property database. Results of the inversion suggest that the remanent vector was acquired sometime between 470 and 420 Ma, likely during the Salinic orogeny. Density information is used to reprocess ground gravity and airborne gravity gradiometry (AGG) data by applying a laterally variable Bouguer and terrain density correction linked to averaged, measured density values and mapped extents of the different tectonostratigraphic groups that make up the BMC. The results of this reprocessing subtly change the gravity and gravity-gradient anomaly patterns allowing for isolated anomalies to be more discretely resolved and reduce the impact of the terrain-related signal in the AGG data. Finally, helicopterborne frequency domain electromagnetic data for a small test site within the BMC are inverted for magnetic susceptibility and forward modelled into a magnetic anomaly grid. Magnetic susceptibility values from the physical property database are used to validate the results of the inversion. This computed near-surface magnetic anomaly grid is then used as a reference to effectively filter measured total magnetic intensity data to represent solely near-surface magnetic sources. Although petrophysical measurements in the BMC may not apply elsewhere, the various methodologies presented are appropriate wherever the geological and geophysical requirements of the method are met.