| Title | Ingress of magmatic Ni-Cu sulphide liquid into surrounding brittle rocks: Physical & structural controls |
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| Author | Saumur, B -M ;
Cruden, A R |
| Source | Ore Geology Reviews vol. 90, 2017 p. 439-445, https://doi.org/10.1016/j.oregeorev.2017.06.009 |
| Image |  |
| Year | 2017 |
| Alt Series | Earth Sciences Sector, Contribution Series 20160372 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Newfoundland and Labrador |
| NTS | 14C/05 |
| Area | Voisey's Bay |
| Lat/Long WENS | -62.0000 -61.5000 56.5000 56.2500 |
| Subjects | igneous and metamorphic petrology; magmatic rocks; sulphides; sulphide deposits; mineral deposits; host rocks; intrusions; deformation |
| Illustrations | photographs; schematic diagrams; graphs |
| Program | GEM2: Geo-mapping for Energy and Minerals Baffin Bedrock Mapping |
| Released | 2017 06 15 |
| Abstract | Field observations and theoretical considerations suggest that dense magmatic sulphide liquids are injected into and/or passively infiltrate surrounding wall rocks late in the emplacement history of
intrusion-hosted magmatic ore systems. In this work, using analogies with other systems, we evaluate the structural and physical controls on the behaviour of sulphide liquid for ingress into brittle host rocks. Gravity-driven infiltration of sulphide
liquid out of the host igneous intrusion into country rock may be analogous to the behaviour of dense fluids in groundwater systems, i.e. Dense Non Aqueous Phase Liquids (DNAPL), which is controlled by the body force of the liquid itself. Downward
penetration of sulphide liquid into micro-fractures may occur once a sufficient thickness of sulphide, known as the critical accumulation height, is reached in the intrusion. Upward and lateral injection of sulphide liquid is a similar process to the
behaviour of crustal hydrothermal fluids, where active deformation, fluid pressure and host-rock anisotropy play critical roles. Such physical controls must be considered and integrated to well-established petro-geochemical concepts in order to
better understand the genesis of magmatic Ni-Cu-PGE sulphide deposits. |
| Summary | (Plain Language Summary, not published)
Sulphur rich magmas, which often host nickel (Ni) and copper (Cu) deposits, are very dense and have a very low viscosity (they are runny like water);
this means that they can easily flow downwards outside of magma intrusions and into the surrounding crust. However, the physics of such processes are poorly understood. We propose different models that help explain some of the features of sulfide
injection and infiltration observed at many Ni-Cu mineral deposits. |
| GEOSCAN ID | 299795 |
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