GEOSCAN Search Results: Fastlink


TitleIntegration of rock properties and geophysics, Bathurst Mining Camp
DownloadDownload (whole publication)
AuthorTschirhart, P A; Morris, W A
SourceTargeted Geoscience Initiative 4: Contributions to the understanding of volcanogenic massive sulphide deposit genesis and exploration methods development; by Peter, J M (ed.); Mercier-Langevin, P (ed.); Geological Survey of Canada, Open File 7853, 2015 p. 101-115, (Open Access)
LinksCanadian Database of Geochemical Surveys, downloadable files
LinksBanque de données de levés géochimiques du Canada, fichiers téléchargeables
PublisherNatural Resources Canada
Documentopen file
Mediaon-line; digital
RelatedThis publication is contained in 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, Geological Survey of Canada, Open File 7853
File formatpdf
ProvinceNew Brunswick
NTS21O/01; 21O/02; 21O/03; 21O/06; 21O/07; 21O/08; 21O/09; 21O/10; 21O/11; 21P/04; 21P/05; 21P/12
AreaHalfmile Lake; Bathurst; Grand Falls; Nepisiguit River
Lat/Long WENS -66.5833 -65.7500 47.7500 47.1333
Subjectseconomic geology; geophysics; mass spectrometer analysis; mineralization; zinc; copper; lead; gold; silver; volcanogenic deposits; sulphide deposits; densities; magnetic susceptibility; geophysical interpretations; Bathurst Mining Camp; Paleozoic; Ordovician
Illustrationslocation maps; tables; plots; images
ProgramTargeted Geoscience Initiative (TGI-4), Volcanogenic Massive Sulfide Ore Systems
Released2015 06 11
AbstractPhysical 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.