Silicification of peridotites at the stalemate fracture zone (Northwestern Pacific): Reconstruction of the conditions of low-temperature weathering and tectonic interpretation

Silantyev, S. A., Novoselov, A. A., Krasnova, E. A., Portnyagin, Maxim V., Hauff, Folkmar and Werner, Reinhard (2012) Silicification of peridotites at the stalemate fracture zone (Northwestern Pacific): Reconstruction of the conditions of low-temperature weathering and tectonic interpretation Petrology, 20 (1). pp. 21-39. DOI 10.1134/S0869591112010055.

[img] Text
2012_Silantyev_Petrology_ENG.pdf - Published Version
Restricted to Registered users only

Download (1927Kb) | Contact

Supplementary data:

Abstract

During cruise SO201-1b of the joint Russian–German expedition on the R/V Sonne in 2009,
mantle peridotites affected by varying secondary alteration were dredged on the eastern slope of the north-
western segment of the Stalemate transverse ridge adjacent to the eponymous fracture zone. The collection
discussed in this paper included four samples of silicified serpentinites after dunites and 11 lherzolite samples
serpentinized to a varying degree. The abundance of amorphous silica and quartz, very high SiO2 content (up
to 88.7 wt %), and unusually low MgO (up to 1.4 wt %) in the serpentinized dunites strongly distinguish these
rocks from the known products of hydrothermal alteration and low-temperature (seafloor) weathering of
peridotites in the oceanic crust. In order to determine the conditions and processes resulting in the silicifica-
tion of peridotites at the Stalemate Fracture Zone, thermodynamic modeling accounting for the kinetics of
mineral dissolution implemented in the GEOCHEQ program package was used in this study. The results of
modeling allowed us to suppose that the geochemical and mineralogical effects observed in the silicified ser-
pentinized dunites of the Stalemate Fracture Zone are consequences of low-temperature deserpentinization
of oceanic materials under subaerial conditions.

Document Type: Article
Additional Information: Original Russian Text © S.A. Silantyev, A.A. Novoselov, E.A. Krasnova, M.V. Portnyagin, F. Hauff, R. Werner, 2012, published in Petrologiya, 2012, Vol. 20, No. 1, pp. 25–44.
Keywords: Meeresgeologie; Abissal peridotites, serpentinites, ocean fracture zone, Pacific, silicification
Research affiliation: OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS Magmatic and Hydrothermal Systems
OceanRep > The Future Ocean - Cluster of Excellence
Refereed: Yes
DOI etc.: 10.1134/S0869591112010055
ISSN: 0869-5911
Projects: Future Ocean
Date Deposited: 30 Jan 2012 11:48
Last Modified: 03 Jan 2017 14:18
URI: http://eprints.uni-kiel.de/id/eprint/13597

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...