Silicic volcanism and hydrothermal activity documented at Pacific-Antarctic Ridge
How well do we know the composition of oceanic crust? Countless studies have described the occurrence of mid-ocean ridge basalt (MORB) at spreading centers, and few would argue that the bulk composition of oceanic crust is other than basaltic. Nevertheless, silicic volcanism (>55 wt.% SiO2) does...
| Published in: | Eos, Transactions American Geophysical Union |
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| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
AGU (American Geophysical Union)
2002
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| Subjects: | |
| Online Access: | https://oceanrep.geomar.de/id/eprint/23660/ https://oceanrep.geomar.de/id/eprint/23660/1/2002EO000215.pdf https://doi.org/10.1029/2002EO000215 |
| Summary: | How well do we know the composition of oceanic crust? Countless studies have described the occurrence of mid-ocean ridge basalt (MORB) at spreading centers, and few would argue that the bulk composition of oceanic crust is other than basaltic. Nevertheless, silicic volcanism (>55 wt.% SiO2) does occur along part of the northern East Pacific Rise (10.5°N; Thompson et al. [1989]),on the 095° propagator of the Galápagos Spreading Center [Clague et al., 1981],and was recently discovered on the Pacific-Antarctic Ridge (PAR) near its intersection with the Foundation seamount chain [Hekinian et al., 1997, 1999]. Silicic lavas were recovered from a 290-km-long section of the northern PAR adjacent to the active Foundation plume (Figure 1) during cruise 157 of the F/S Sonne, which took place in June and July 2001. Furthermore, widespread hydrothermal activity indicates that the volcanogenic massive sulfidesilicic lava association is not only restricted to subduction and back arc settings. |
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