Early Cambrian forearc ophiolite-hosted VMS-type Cu deposit in the North Qaidam belt, northern Tibetan Plateau

Fu, Changlei; Wang, Bingzhang; Yan, Zhen; Aitchison, Jonathan C.; Xiao, Wenjiao; Buckman, Solomon; Li, Wufu

doi:10.1016/j.geogeo.2022.100172

Cited by 1 publication

(10 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, unit C is interpreted as submarine fan sediments deposited in an intra‐oceanic forearc basin (Chen et al., 2022) (Figure 5). The Shimiangou ophiolitic rocks have Cambrian ages of 512–506 Ma and contain high‐Cr spinels, which are consistent with those known from forearc ophiolites at Lüliangshan (Fu et al., 2022a, 2023). These results suggest the existence of an accretionary complex at a continental margin (unit A‐2) and intra‐oceanic forearc terrane (including units A‐1, C, and ophiolite) (Figure 5).…”

Section: Discussionsupporting

confidence: 78%

“…This study mainly focuses on unit B within the Tanjianshan Group in the Tuomoerrite area. It is further subdivided, based on the rock assemblage and geochemical data, into three belts separated by thrust faults, namely 2015) and Fu et al (2022aFu et al ( , 2023; continental arc intrusive rocks are from Li et al (2018bLi et al ( , 2022 and Gao et al (2021). AC-accretionary complex; FB-forearc basin; IA-intra-oceanic arc.…”

Section: Field Geology and Petrographymentioning

confidence: 99%

“…490 Ma and lack Precambrian zircons derived from the adjacent microcontinents (Figures 4 and 5). The ophiolite complex in the North Qaidam belt formed in a forearc setting, as evidenced by the forearc basalt, boninitic lava and high-Cr spinels in the serpentinite (Chen et al, 2020;Fu et al, 2022aFu et al, , 2023.…”

Section: Intra-oceanic or Continental Margin Subductionmentioning

confidence: 99%

“…Subunit A-2 lies close to the northern Paleoproterozoic Delingha Complex, which is part of the metamorphic basement of the Oulongbuluke block. It is dominated by psammitic schist with some mafic blocks (Fu et al, 2022c) (Figures 4 and 5). Unit B is exposed near Keke Lake and is separated from northeastern subunit A-2 by a south-verging thrust fault.…”

Section: Composition Of the Tanjianshan Groupmentioning

confidence: 99%

“…The Tanjianshan Group in Tuomoerrite area, eastern part of North Qaidam belt, is subdivided into four mappable units, viz., A-1, A-2, B and C, based on the result of geological mapping (Chen et al, 2022;Fu et al, 2022aFu et al, , 2022c) (Figures 4 and 5). Subunits A-1 and A-2 are represented by volcano-sedimentary rocks with block-in-matrix textures exposed in the southern part (Bulagesita) and NE part (Tuoxingou), respectively.…”

Section: Composition Of the Tanjianshan Groupmentioning

confidence: 99%

See 4 more Smart Citations

Subduction Within the Proto‐Tethys Ocean Revealed by Recognition of the Earliest Phanerozoic Intra‐Oceanic Arc, Northern Tibetan Plateau

Fu,

Yan,

Aitchison

et al. 2024

Earth and Space Science

Self Cite

View full text Add to dashboard Cite

The possibility that the Proto‐Tethys Ocean may have undergone intra‐oceanic subduction during ocean closure remains poorly constrained due to a lack of geological evidence for a mature intra‐oceanic arc. Here we present new geochemical and geochronological data for potential arc‐related volcanic rocks adjacent to the accretionary complex and forearc basin in the North Qaidam collisional belt, northern Tibetan Plateau. The volcanic rocks are dominated by foliated basalt, andesite, tuff, and minor dacite with zircon U‐Pb ages ranging from 517 to 497 Ma. They show distinctive geochemical characteristics and can be subdivided into three groups: island‐arc intermediate‐basic volcanic rocks, back‐arc basin basalts (BABB), and dacites with intra‐oceanic arc affinity. The island‐arc volcanic rocks have variable εNd(t) values (+1.6 to +7.5) that decrease northward and were generated by partial melting of depleted mantle wedge modified by hydrous fluid and sediment melt. The BABBs have high εNd(t) values (+5.3 to +6.6) and formed through the melting of MORB‐like mantle, whereas the nearby dacites have positive εNd(t) values (+1.9 to +3.6) similar to the surrounding island‐arc volcanic rocks and were derived from partial melting of intra‐oceanic arc crust as a result of BABB underplating. Integrated analysis of the spatial‐temporal distribution of these volcanic rocks and the reconstructed intra‐oceanic arc‐trench system confirms the existence of the earliest Phanerozoic intra‐oceanic arc formed in response to north‐directed intra‐oceanic subduction. This unrecognized subduction of the Proto‐Tethys Ocean in the North Qaidam belt initiated at ca. 530 Ma, matured ca. 520 Ma, and terminated by ca. 480 Ma.

show abstract

Section: Discussionsupporting

confidence: 78%