Subduction erosion is important for crustal material recycling and is widespread in modern active convergent margins. However, such a process is rarely identified in fossil convergent systems, which casts doubt on the importance of subduction erosion through the geological record. We report on ca. 155 Ma Kangqiong (pluton) intrusive rocks of a Mesozoic magmatic arc in the southern Qiangtang terrane, central Tibet. These rocks mainly consist of trondhjemites and tonalites and are similar to slab-derived adakites with mantle-like zircon oxygen isotope compositions (δ18O = 5.2‰–5.6‰), they display more evolved Sr-Nd isotopes and higher Th/La relative to mid-oceanic ridge basalts from the Bangong-Nujiang suture, and they contain abundant amphibole and biotite. These characteristics indicate magma generation via H2O-fluxed melting of eroded forearc crust debris with subducted oceanic crust at 1.5–2.5 GPa and 700–800 °C. In addition, the intrusions are exposed <20 km north of the Bangong-Nujiang suture. Given the formation of adakites, narrow arc-suture distance, migration of the Jurassic frontal arc toward the continent interior, and other independent geological archives, we suggest that the hydrated forearc crust materials were removed from the overlying plate and carried into the mantle by subduction erosion. Our study provides the first direct magmatic evidence for a subduction erosion process in pre-Cenozoic convergent systems, which confirms an important role for such processes in subduction-zone material recycling.
Skip Nav Destination
Close
Article navigation
Article Contents
Research Article|
February 22, 2021
Subduction erosion and crustal material recycling indicated by adakites in central Tibet
Zong-Yong Yang
;
Zong-Yong Yang
1
State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China2
CAS Center for Excellence in Deep Earth Sciences, Guangzhou 510640, China3
State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China4
College of Earth and Planetary Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
Search for other works by this author on:
Qiang Wang
;
Qiang Wang
1
State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China2
CAS Center for Excellence in Deep Earth Sciences, Guangzhou 510640, China4
College of Earth and Planetary Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
Search for other works by this author on:
Lu-Lu Hao
;
Lu-Lu Hao
1
State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
Search for other works by this author on:
Derek A. Wyman
;
Derek A. Wyman
5
School of Geosciences, The University of Sydney, Camperdown, New South Wales 2006, Australia
Search for other works by this author on:
Lin Ma
;
Lin Ma
1
State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
Search for other works by this author on:
Jun Wang
;
Jun Wang
1
State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China2
CAS Center for Excellence in Deep Earth Sciences, Guangzhou 510640, China
Search for other works by this author on:
Yue Qi
;
Yue Qi
1
State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China2
CAS Center for Excellence in Deep Earth Sciences, Guangzhou 510640, China
Search for other works by this author on:
Peng Sun
;
Peng Sun
1
State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China4
College of Earth and Planetary Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
Search for other works by this author on:
Wan-Long Hu
Wan-Long Hu
1
State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China4
College of Earth and Planetary Sciences, University of the Chinese Academy of Sciences, Beijing 100049, China
Search for other works by this author on:
Geology (2021)
Article history
received:
06 Oct 2020
rev-recd:
20 Dec 2020
accepted:
24 Dec 2020
first online:
22 Feb 2021
Citation
Zong-Yong Yang, Qiang Wang, Lu-Lu Hao, Derek A. Wyman, Lin Ma, Jun Wang, Yue Qi, Peng Sun, Wan-Long Hu; Subduction erosion and crustal material recycling indicated by adakites in central Tibet. Geology 2021; doi: https://doi.org/10.1130/G48486.1
Download citation file:
Close
You could not be signed in. Please check your email address / username and password and try again.