Ordovician adakite-Nb-enriched basalt suite in the eastern North Qaidam Mountains: Implications for oceanic subduction and crustal accretion prior to deep continental subduction

路增龙,; Lu, Zenglong; 张建新,; Zhang, Jianxin; 毛小红,; Mao, Xiaohong; 周桂生,; Zhou, Guisheng; Xia, TENG; Teng, Xiaoyan; 武亚威,; Wu, Yawei

doi:10.18654/1000-0569/2020.10.05

Cited by 3 publications

(2 citation statements)

References 120 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the Cr-Ni diagram, the samples display low Cr and Ni contents, reflecting characteristics of slab melting (Figure 9a), while also exhibiting characteristics of O-type adakite. The intrusive rocks studied in this research exhibit highly consistent patterns in their rare-earth elements and trace elements, showing pronounced light-heavy rare-earth fractionation, which distinguishes them from island arc calc-alkaline series rocks [68]. Analysis using La-(La/Yb)N and Sm-La/Sm diagrams similarly reveals significant partial melting features in the studied adakitic rocks, without significant crystal fractionation, indicating they are not products of primary basaltic magma separation (Figure 9b,c).…”

Section: Identification Of Adakitementioning

confidence: 78%

“…Considering the above studies, the formation of adakites can be summarized into three main types: (1) partial melting of subducted oceanic slab; (2) basaltic intrusion and partial melting of mantle or lower crust ultramafic and mafic rocks; (3) crystallization under highpressure conditions in the initial arc magma of island arc settings [67,68]. The classification of adakites indicates that O-type adakites and High-SiO 2 adakites share similar chemical characteristics, both representing Na-enriched oceanic crust-derived adakitic rocks, consistent with the original definition of adakites, referred to as "typical adakites" [54].…”

Section: Identification Of Adakitementioning

confidence: 99%

See 1 more Smart Citation

Discovery of Late Permian Adakite in Eastern Central Asian Orogenic Belt: Implications for Tectonic Evolution of Paleo-Asian Ocean

Zhang,

Qiu,

Zhang

et al. 2024

Minerals

View full text Add to dashboard Cite

The Permian to Triassic period represents a pivotal phase in the evolution of the Paleo-Asian Ocean, marked by significant tectonic transitions from subduction, collision, and post-orogenic extension. The timing of closure of the Paleo-Asian Ocean in northeastern China has always been controversial. In this contribution, the petrology, zircon U-Pb geochronology and geochemistry are conducted on granite found in well HFD1, Songliao Basin, eastern part of Central Asian orogenic belt. Zircon U-Pb dating indicates that granite crystallized at 258.9 ± 2.2 Ma, as the product of magmatism occurred in the early Late Permian. The rocks have high SiO2, Al2O3, Na2O content, negative Eu anomaly, light enrichment of rare-earth elements, depletion of heavy rare-earth elements, high Sr (448.29–533.11 ppm, average 499.68 ppm), low Yb (0.49–0.59 ppm, average 0.54 ppm), Y (4.23–5.19 ppm, average 4.49 ppm), and high Sr/Y ratios (98–125, average 112) and can be classified as O-type adakite. This is the first discovery of late Paleozoic adakite in the Songliao Basin and the neighboring areas. The geochemistry of adakite indicates derivation by partial melting of MORB-type subducted oceanic crust, indicating that the subduction of the Paleo-Asian Oceanic lithosphere lasted until at least 258.9 Ma.

show abstract

Section: Identification Of Adakitementioning

confidence: 78%

Section: Identification Of Adakitementioning

confidence: 99%

Discovery of Late Permian Adakite in Eastern Central Asian Orogenic Belt: Implications for Tectonic Evolution of Paleo-Asian Ocean

Zhang,

Qiu,

Zhang

et al. 2024

Minerals

View full text Add to dashboard Cite

show abstract

Provenance change in Carboniferous-early Permian sedimentary successions in the North Qaidam tectonic belt, northern Tibetan Plateau: Implications for the Kunlun oceanic plate subduction process

Wang

Zhou

et al. 2022

Journal of Asian Earth Sciences

View full text Add to dashboard Cite

Timing of Transition from Proto- to Paleo-Tethys: Evidence from the Early Devonian Bimodal Volcanics in the North Qaidam Tectonic Belt, Northern Tibetan Plateau

Wang

Pei

et al. 2023

Minerals

View full text Add to dashboard Cite

The transition from the Proto- to the Paleo-Tethys is still a controversial issue. This study reports a new petrology, zircon U–Pb geochronology, and whole-rock geochemistry of volcanic rocks from the Maoniushan Formation in the Nankeke area, northern Qaidam (NQ) of the Tibetan Plateau, to provide new evidence for the transition from the Proto- to the Paleo-Tethys oceans. The volcanic suite consists mainly of rhyolitic crystal lithic tuff lavas and minor basalts. Zircon U–Pb data indicate that the bimodal volcanic rocks were formed during the Early Devonian (ca. 410–409 Ma). Geochemically, the basalts have low contents of SiO2 (48.92 wt.%–51.19 wt.%) and relatively high contents of MgO (8.94 wt.%–9.99 wt.%), TiO2 (1.05 wt.%–1.29 wt.%), K2O (2.35 wt.%–4.17 wt.%), and K2O/Na2O ratios (1.04–2.56), showing the characteristics of calc-alkaline basalts. Their rare earth element (REE) patterns and trace element spider diagrams are characterized by enrichments in LREEs (LREE/HREE = 18.31–21.34) and large ion lithophile elements (LILEs; Rb, Th, and K) and depletion in high-field-strength elements (HFSEs; Nb, Ta, P, and Ti), with slight negative Eu anomalies (Eu/Eu* = 0.82–0.86), which are similar to Etendeka continental flood basalts (CFB). These features suggest that the basalts were most likely derived from low degree (1%–5%) partial melting of the asthenospheric mantle, contaminated by small volumes of continental crust. In contrast, the felsic volcanics have high SiO2 (68.41 wt.%–77.12 wt.%), variable Al2O3 (9.56 wt.%–12.62 wt.%), low MgO, and A/CNK ratios mostly between 1.08 and 1.15, defining their peraluminous and medium-K calc-alkaline signatures. Their trace element signatures show enrichments of LREEs and LILEs (e.g., Rb, Th, U, K, and Pb), depletion of HFSEs (e.g., Nb, Ti, Ta, and P), and negative Eu anomalies (Eu/Eu* = 0.22–0.66). These features suggest that the felsic volcanics were derived from partial melting of the middle crust, without interaction with mantle melts. Considering all the previous data and geochemical features, the Maoniushan Formation volcanic rocks in NQ formed in a post-collisional extensional setting associated with asthenospheric mantle upwelling and delamination in the Early Devonian. Together with the regional data, this study proposed that the Proto-Tethys Ocean had closed and evolved to the continental subduction/collision orogeny stage during the Middle to Late Ordovician, evolved to the post-collisional extensional stage in the Early Devonian, and finally formed the Zongwulong Ocean (branches of the Paleo-Tethys Ocean) in the Late Carboniferous, forming the tectonic framework of the Paleo-Tethys Archipelagic Ocean in the northern margin of the Tibetan Plateau.

show abstract

Ordovician adakite-Nb-enriched basalt suite in the eastern North Qaidam Mountains: Implications for oceanic subduction and crustal accretion prior to deep continental subduction

Cited by 3 publications

References 120 publications

Discovery of Late Permian Adakite in Eastern Central Asian Orogenic Belt: Implications for Tectonic Evolution of Paleo-Asian Ocean

Discovery of Late Permian Adakite in Eastern Central Asian Orogenic Belt: Implications for Tectonic Evolution of Paleo-Asian Ocean

Provenance change in Carboniferous-early Permian sedimentary successions in the North Qaidam tectonic belt, northern Tibetan Plateau: Implications for the Kunlun oceanic plate subduction process

Timing of Transition from Proto- to Paleo-Tethys: Evidence from the Early Devonian Bimodal Volcanics in the North Qaidam Tectonic Belt, Northern Tibetan Plateau

Contact Info

Product

Resources

About