Massive sulfides in a sedimented rift valley, northern Juan de Fuca Ridge
Davis, E.; Goodfellow, W.D.; Bornhold, B.D.; Adshead, J.; Blaise, B.; Villinger, H.; Le Cheminant, G.M. (1987). Massive sulfides in a sedimented rift valley, northern Juan de Fuca Ridge. Earth Planet. Sci. Lett. 82(1): 49-61. https://dx.doi.org/10.1016/0012-821X(87)90106-3
In: Earth and Planetary Science Letters. Elsevier: Amsterdam. ISSN 0012-821X; e-ISSN 1385-013X, more
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| Keywords |
Data > Oceanographic data > Bathymetric data
Imagery > Acoustic imagery
INE, Juan de Fuca Ridge
Mineralogy
Samples > Geological samples > Sediment samples > Cores
Sediments > Chemical sediments > Sulphide deposits
Topographic features > Landforms > Valleys > Rift valleys
Water > Sea water
Water springs > Geothermal springs > Hydrothermal springs
Juan de Fuca Ridge [Marine Regions]
Marine/Coastal |
| Authors | | Top |
- Davis, E.
- Goodfellow, W.D.
- Bornhold, B.D.
- Adshead, J.
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- Blaise, B.
- Villinger, H.
- Le Cheminant, G.M.
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| Abstract |
A number of mounds believed to be of hydrothermal origin each several hundred m across and up to sixty m high have been observed with SeaMARC II acoustic imagery and Seabeam bathymetry in the sediment-filled axial valley at the northern end of the Juan de Fuca Ridge. A piston core collected from that mound comprises coarse clastic sulfide units interbedded with sulfidic muds. Hydrothermal minerals present in the 2.3 m section include pyrrhotite, pyrite, marcasite, sphalerite, chalcopyrite, iss (intermediate solid solution in the Cu-Fe-Zn-S system), chalcopyrrhotite, galena, talc, barite, and amorphous silica. Mineral fabrics of the clasts indicate that the material was precipitated at or near the sea floor by mixing of hot hydrothermal fluids with cold seawater. Rapid sedimentation in a rift valley is clearly conducive to the formation of large hydrothermal mineral deposits like those believed to be present within and beneath these mounds. No reliable estimate of the bulk composition of the mounds can be made with existing data, but their size is comparable to major hydrothermal mineral deposits found on land. |
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