TY - JOUR
T1 - Deep Sourced Fluids for Peridotite Carbonation in the Shallow Mantle Wedge of a Fossil Subduction Zone
T2 - Sr and C Isotope Profiles of OmanDP Hole BT1B
AU - Oman Drilling Project Phase 1 Science Party
AU - de Obeso, Juan Carlos
AU - Kelemen, Peter B.
AU - Leong, James M.
AU - Menzel, Manuel D.
AU - Manning, Craig E.
AU - Godard, Marguerite
AU - Cai, Yue
AU - Bolge, Louise
AU - Matter, Jürg
AU - Teagle, Damon
AU - Coggon, Jude
AU - Harris, Michelle
AU - Bennett, Emma
AU - Bompard, Nico
AU - Boulanger, Marine
AU - France, Lyderic
AU - Früh-Green, Gretchen
AU - Garbe-Schönberg, Dieter
AU - Ildefonse, Benoit
AU - Jesus, Ana
AU - Koepke, Jürgen
AU - Koornneef, Louise
AU - Lafay, Romain
AU - Lissenberg, Johan
AU - MacLeod, Chris
AU - Mock, Dominik
AU - Morris, Tony
AU - Müller, Samuel
AU - Noël, Julie
AU - Nothaft, Daniel
AU - Perez, Americus
AU - Pezard, Philippe
AU - Warsi, Nehal
AU - Zeko, David
AU - Zihlmann, Barbara
AU - Bechkit, Mohamed Amine
AU - Brun, Laurent
AU - Célérier, Bernard
AU - Henry, Gilles
AU - Paris, Jehanne
AU - Lods, Gérard
AU - Robert, Pascal
AU - Al Amri, Salim
AU - Al Shukaili, Mohsin
AU - Al Qassabi, Ali
AU - Moe, Kyaw
AU - Yamada, Yasu
AU - Takazawa, Eiichi
AU - Michibayashi, Katsuyoshi
AU - Till, Jessica
N1 - Publisher Copyright:
© 2021. American Geophysical Union. All Rights Reserved.
PY - 2022/1
Y1 - 2022/1
N2 - Completely carbonated peridotites represent a window to study reactions of carbon-rich fluids with mantle rocks. Here, we present details on the carbonation history of listvenites close to the basal thrust in the Samail ophiolite. We use samples from Oman Drilling Project Hole BT1B, which provides a continuous record of lithologic transitions, as well as outcrop samples from listvenites, metasediments, and metamafics below the basal thrust of the ophiolite. 87Sr/86Sr of listvenites and serpentinites, ranging from 0.7090 to 0.7145, are significantly more radiogenic than mantle values, Cretaceous seawater, and other peridotite hosted carbonates in Oman. The Hawasina sediments that underlie the ophiolite, on the other hand, show higher 87Sr/86Sr values of up to 0.7241. δ13C values of total carbon in the listvenites and serpentinites range from −10.6‰ to 1.92‰. We also identified a small organic carbon component with δ13C as low as −27‰. Based on these results, we propose that during subduction at temperatures above >400°C, carbon-rich fluids derived from decarbonation of the underlying sediments migrated updip and generated the radiogenic 87Sr/86Sr signature and the fractionated δ13C values of the serpentinites and listvenites in core BT1B.
AB - Completely carbonated peridotites represent a window to study reactions of carbon-rich fluids with mantle rocks. Here, we present details on the carbonation history of listvenites close to the basal thrust in the Samail ophiolite. We use samples from Oman Drilling Project Hole BT1B, which provides a continuous record of lithologic transitions, as well as outcrop samples from listvenites, metasediments, and metamafics below the basal thrust of the ophiolite. 87Sr/86Sr of listvenites and serpentinites, ranging from 0.7090 to 0.7145, are significantly more radiogenic than mantle values, Cretaceous seawater, and other peridotite hosted carbonates in Oman. The Hawasina sediments that underlie the ophiolite, on the other hand, show higher 87Sr/86Sr values of up to 0.7241. δ13C values of total carbon in the listvenites and serpentinites range from −10.6‰ to 1.92‰. We also identified a small organic carbon component with δ13C as low as −27‰. Based on these results, we propose that during subduction at temperatures above >400°C, carbon-rich fluids derived from decarbonation of the underlying sediments migrated updip and generated the radiogenic 87Sr/86Sr signature and the fractionated δ13C values of the serpentinites and listvenites in core BT1B.
KW - listvenite
KW - Oman
KW - Oman Drilling Project
KW - ophiolite
KW - peridotite
KW - serpentinization
UR - http://www.scopus.com/inward/record.url?scp=85131386836&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85131386836&partnerID=8YFLogxK
U2 - 10.1029/2021JB022704
DO - 10.1029/2021JB022704
M3 - Article
AN - SCOPUS:85131386836
SN - 2169-9313
VL - 127
JO - Journal of Geophysical Research: Solid Earth
JF - Journal of Geophysical Research: Solid Earth
IS - 1
M1 - e2021JB022704
ER -