TY  - JOUR
A1  - Menzel, Manuel D.
A1  - Urai, Janos L.
A1  - de Obeso, Juan Carlos
A1  - Kotowski, Alissa
A1  - Manning, Craig E.
A1  - Kelemen, Peter B.
A1  - Kettermann, Michael
A1  - Jesus, Ana P.
A1  - Harigane, Yumiko
A1  - and the Oman Drilling Project Phase 1 Science Team
T1  - Brittle Deformation of Carbonated Peridotite—Insights From Listvenites of the Samail Ophiolite (Oman Drilling Project Hole BT1B)
Y1  - 2020
VL  - 125
IS  - 10
JF  - Journal of Geophysical Research: Solid Earth
DO  - 10.1029/2020JB020199
DO  - 10.23689/fidgeo-4671
N2  - Hole BT1B of the Oman Drilling Project provides a continuous sampling from listvenite into the metamorphic sole that preserves the deformation, hydration, and carbonation processes of oceanic mantle peridotite at the base of the Samail ophiolite, Oman. We present evidence of multistage brittle deformation in listvenites and serpentinites based on field observations, visual core logging and petrography. About 10 vol% of listvenite and serpentinite in Hole BT1B is composed of cataclasite bands. Cataclasites contain lithic clasts of listvenite with spheroidal, zoned magnesite and quartz, and fragments of chalcedony-carbonate veins that elsewhere crosscut listvenite—showing that cataclasis postdates listvenite formation. Locally the cataclasites are reworked and cut by thin, sharp faults, pointing to repeated reactivation of brittle structures. SEM-EDS mapping shows that cataclasis was related to dissolution of carbonate and/or silica cementation. Dolomite veins crosscut cataclasites and breccias, suggesting that part of the Ca gain in BT1B is related to late fluids after listvenite formation. These results indicate a multistage tectonic overprint after peridotite carbonation and listvenite formation, which may be related to the tectonic history of the deformed continental margin under the ophiolite. These relatively late brittle structures should be excluded when trying to understand the carbonation of peridotite to listvenite.
UR  - http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/9017
ER  -