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An Early Cretaceous slab window beneath central Tibet, SW China: Evidence from OIB ‐like alkaline gabbros in the Duolong area
Author(s) -
Wu Hao,
Sun Shulin,
Liu Haiyong,
Chu Hao,
Ding Wei
Publication year - 2019
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/ter.12370
Subject(s) - geology , fibrous joint , geochemistry , slab , upwelling , cretaceous , asthenosphere , terrane , gabbro , slab window , window (computing) , subduction , basalt , paleontology , tectonics , oceanic crust , oceanography , medicine , computer science , anatomy , operating system
The geodynamic mechanism of the late Early Cretaceous magmatic flare‐up in the collisional zone between the Lhasa and Qiangtang terranes in Tibet is controversial because of a scarcity of robust evidence. To address this problem, we report geochronological, geochemical and Hf isotopic data for the newly discovered Gufeng gabbros from the Duolong Cu–Au mineral district of the western Bangong–Nujiang Suture Zone ( BNSZ ). The gabbro samples, dated at 126.3 ± 1.8 Ma, show geochemical similarities to typical ocean island basalt ( OIB ) and have positive εHf(t) values of +3.3 to +6.9. The gabbros were generated by decompression melting of deep upwelling asthenosphere. This event is best explained by slab break‐off and the resultant development of a slab window beneath central Tibet.