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TitleReprocessing legacy three-dimensional seismic data from the Halfmile Lake and Brunswick No. 6 volcanogenic massive sulphide deposits, New Brunswick, Canada
AuthorBellefleur, G; Cheraghi, S; Malehmir, A
SourceGeophysics applied to mineral exploration; by Pinet, N (ed.); Pilkington, M (ed.); McCuaig, M (ed.); Canadian Journal of Earth Sciences vol. 56, no. 5, 2018 p. 569-583, (Open Access)
Alt SeriesNatural Resources Canada, Contribution Series 20180030
PublisherCanadian Science Publishing
Mediapaper; on-line; digital
File formatpdf (Adobe® Reader®); html
ProvinceNew Brunswick
NTS21O/01; 21O/02; 21O/07; 21O/08; 21O/09; 21O/10; 21O/15; 21O/16; 21P/04; 21P/05; 21P/12; 21P/13
Lat/Long WENS -66.6250 -65.5000 48.0000 47.0000
Subjectseconomic geology; geophysics; Science and Technology; mineral deposits; mineral potential; volcanogenic deposits; sulphide deposits; mineralization; geophysical interpretations; seismic interpretations; seismic methods; seismic models; seismic velocities; anomalies; structural interpretations; fold geometry; bedrock geology; structural features; faults; faults, thrust; folds; anticlines; synclines; unconformities; lithology; igneous rocks; volcanic rocks; lava flows; basalts; andesites; rhyolites; breccias; tuffs; iron formations; volcaniclastics; ash; intrusive rocks; gabbros; sedimentary rocks; sandstones; siltstones; shales; drillholes; Bathurst Mining Camp; Halfmile Lake Deposit; Brunswick No. 6 Deposit; Halfmile Lake Anticline; Tetagouche Group; Flat Landing Brook Formation; Nepisiguit Falls Formation; Miramichi Group; Patrick Brook Formation; volcanogenic massive sulphide deposits (VMS); data processing; geological mapping; 3-D mapping; exhalites; wackes; legacy datasets; Phanerozoic; Paleozoic; Ordovician; Cambrian
Illustrationslocation maps; geoscientific sketch maps; seismic profiles; cross-sections; geophysical images
ProgramTargeted Geoscience Initiative (TGI-5), Volcanic and sedimentary systems
Released2018 08 23
AbstractWe reprocessed legacy three-dimensional (3D) seismic data from the Halfmile Lake and Brunswick areas, both of which were acquired for mineral exploration in the Bathurst Mining Camp, New Brunswick. Each 3D seismic survey was acquired over known volcanogenic massive sulphide deposits and covered areas with strong mineral potential. Most improvements resulted from a reduction of coherent and random noise on prestack gathers and from an improved velocity model, combined with re-imaging with dip moveout corrections and poststack migration or prestack time migration. At Halfmile Lake, the new imaging results show the Deep zone and a possible extension of the sulphide mineralization at greater depth. True amplitude processing has shown that this anomaly has strong amplitudes and is offset from the Deep zone by a shallowly dipping fault (<15°). With the clearer geological context provided by our results, this anomaly, which appears as a stand-alone anomaly on an original image obtained by Noranda Exploration Ltd., becomes a defendable exploration target. Nonorthogonal acquisition geometry and receiver patches of the Brunswick No. 6 3D seismic survey generated artefacts after dip moveout processing that reduced the overall quality of the seismic volumes. By using a filtering approach based on the application of a weighted Laplacian-Gaussian filter in the Kx-Ky domain, we reduced the noise and improved the continuity of reflections. We also imaged the short and flat reflections observed previously only in the shallow part of prestack time migrated data. These short reflections appear as diffractions on the filtered stacked section with dip moveout corrections, indicating that they originate from small geological bodies or discontinuities in the subsurface.
Summary(Plain Language Summary, not published)
We looked at legacy 3D seismic data from the Halfmile Lake and Brunswick mine areas and re-processed them with state-of-the-art algorithms to improve the image of the subsurface. At Halfmile Lake, the new imaging results show a known mineralized zone and an anomaly that is a possible extension of the sulphide mineralization at a depth of 1.5 km. At Brunswick, the re-processing revealed short reflections originating from small bodies or discontinuities which provide additional information on the subsurface geology.