| Title | Application of seismic methods to mineral exploration |
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| Author | Salisbury, M; Snyder, D |
| Source | Mineral deposits of Canada: a synthesis of major deposit-types, district metallogeny, the evolution of geological provinces, and exploration methods; by Goodfellow, W D (ed.); Geological Association of
Canada, Mineral Deposits Division, Special Publication no. 5, 2007 p. 971-982 |
| Image |  |
| Year | 2007 |
| Alt Series | Earth Sciences Sector, Contribution Series 20070220 |
| Publisher | Geological Association of Canada, Mineral Deposits Division (St. John's, NL, Canada) |
| Document | serial |
| Lang. | English |
| Media | paper; DVD; digital |
| Related | This publication is contained in Mineral deposits of Canada:
a synthesis of major deposit-types, district metallogeny, the evolution of geological provinces, and exploration methods |
| File format | pdf |
| Subjects | economic geology; geophysics; mineral exploration; exploration; seismic exploration; exploration methods; seismic velocities; densities; reflection studies; seismic reflection surveys; seismic profiles;
mineralization; diamond; gold; copper; nickel; platinum; sulphides; Mississippi Valley deposits; porphyry deposits; porphyry copper; uranium; iron oxides |
| Illustrations | graphs; profiles |
| Program | Consolidating Canada's Geoscience Knowledge |
| Program | Targeted Geoscience Initiative (TGI-3), 2005-2010 |
| Released | 2007 01 01 |
| Abstract | Plots of compressional (Vp) and shear (Vs) wave velocity vs. density for rocks at elevated confining pressures show that velocities tend to increase with density along the well known Nafe-Drake curves
for silicate rocks. Because of their high densities, however, many ores fall far to the right of the Nafe-Drake curves and display higher impedances than their common hosts, suggesting that it should be possible to detect and prospect for ores using
high-resolution reflection techniques if the deposits meet the size, thickness, and presentation constraints required for reflection or diffraction. Experiments conducted by the Geological Survey of Canada, universities, and industry in hardrock
mining camps across Canada over the past decade show that 2-D surveys are well suited to the determination of structure and the detection of orebodies, while 3-D surveys may be used for detection and delineation, and vertical seismic profiling (VSP)
for delineation. Due to the small size of most deposits, the structural complexity of hard rock terranes and their low signal-to-noise ratios, the best results are obtained from carefully designed surveys using high frequency sources and customized
processing sequences designed to identify both reflections and diffractors.
2-D and 3-D surveys have successfully detected and imaged large massive sulphide deposits such as the magmatic and volcanic massive sulphide (VMS) deposits in Sudbury
and Bathurst and should also be useful for the detection of massive sedimentary exhalitive (SEDEX) and iron oxide copper gold (IOCG) deposits. Other types of deposits are more likely to be detected indirectly: lode gold and porphyry deposits by
reflections from alteration haloes, unconformity Uranium deposits by haloes and basement offsets, and Mississippi Valley-type (MVT) deposits by white spots in otherwise reflective carbonates. Similarly, the high impedances between kimberlites and
their hosts allow pipes to be delineated using VSP techniques. |
| GEOSCAN ID | 224213 |
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