| Title | Scaling behavior and the effects of heterogeneity on shallow seismic imaging of mineral deposits: a case study from Brunswick No. 6 mining area, Canada |
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| Author | Cheraghi, S; Malehmir, A; Bellefleur, G ; Bongajum, E; Bastani, M |
| Source | Journal of Applied Geophysics vol. 90, 2013 p. 1-18, https://doi.org/10.1016/j.jappgeo.2012.12.003 |
| Image |  |
| Year | 2013 |
| Alt Series | Earth Sciences Sector, Contribution Series 20120174 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | New Brunswick |
| NTS | 21P/05 |
| Area | Bathurst |
| Lat/Long WENS | -65.9056 -65.7956 47.4567 47.3872 |
| Subjects | geophysics; analytical methods; mineral deposits; seismic methods; statistical methods; seismic reflection surveys; seismic velocities; density logging; Brunswick No. 6 mine |
| Illustrations | geological sketch maps |
| Program | Targeted Geoscience Initiative (TGI-4) Methodological Development |
| Program | Targeted Geoscience Initiative (TGI-4) Volcanogenic Massive Sulfide Ore Systems |
| Released | 2013 03 01 |
| Abstract | We have studied the scaling behavior of compressional-wave velocity and density logs from an exploration borehole that extends down to about 700 m depth in the Brunswick No. 6 mining area, Bathurst
Mining Camp, Canada. Using statistical methods, vertical and horizontal scale lengths of heterogeneity were estimated. Vertical scale length estimates from the velocity, density and calculated acoustic impedance are 14 m, 33 m,
and about 20 m,
respectively. Although the estimated scale length for the acoustic impedance implies a weak scattering environment, elastic finite difference modeling of seismic wave propagation in 2D heterogeneous media demonstrates that even this weak scattering
medium can mask seismic signals from small, but yet economically feasible, massive sulfide deposits. Further analysis of the synthetic seismic data suggests that in the presence of heterogeneity, lenticular-shaped targets may only exhibit incomplete
diffraction signals whereby the down-dip tails of these diffractions are mainly visible on the stacked sections. Therefore, identification of orebody generated diffractions is much easier on the unmigrated stacked sections than on migrated stacked
sections. The numerical seismic modeling in 2D heterogeneous media indicates that in the presence of large horizontal, but small vertical scale lengths (structural anisotropy), identification of massive sulfide deposits is possible, but their
delineation at depth requires detailed velocity modeling and processing algorithms which can handle the anisotropy. |
| GEOSCAN ID | 291720 |
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