Magma assembly and evolution of the Early Cretaceous Sanguliu pluton in the Liaodong Peninsula, NE China

Abstract The Lushun-Dalian area of the South Liaodong Peninsula, in NE China, located in the SE margin of the North China Craton (NCC) exposes a suite of Middle-Late Proterozoic low-grade metamorphic sedimentary rocks which can be divided into a lower competent layer, a middle incompetent layer, and an upper competent layer on the basis of lithology and deformation style. Two stages of deformation recorded both in the metasedimentary rocks and a magmatic complex intruded in them indicate that the Lushun-Dalian area is a key region to decipher the Triassic–Jurassic tectonic evolution of the eastern NCC. The earliest D1 deformation mylonitized the magmatic complex and thrusted it northeastward over the low-grade metasedimentary rocks, in which a series of NE-verging folds and NE-directed brittle thrust faults developed. The D2 deformation erased the D1 fabrics in the incompetent layer by a top-to-the-NW ductile shearing and refolded the D1 fabrics in the lower and upper competent units, producing a series of km-scale SW-plunging folds. New zircon secondary ion mass spectrometry and laser ablation–inductively coupled plasma–mass spectrometry U-Pb ages from the magmatic complex and the granite porphyry dikes intruded in it, combined with the unconformity between the low-grade metasedimentary rocks and the Early Cretaceous volcanic rocks, indicate that D1 and D2 occurred after 211 Ma and before the Early Cretaceous. The decrease of the deformation intensity of D1 and D2 from the Lushun-Dalian area toward the interior of the NCC in the NE and NW directions suggests that D1 was the structural response in the overriding plate to the NCC-South China Block convergence during the Late Triassic to Early Jurassic, and D2 was the structural response to the northwestward subduction of the Paleo–Pacific plate beneath the NCC in the Middle-Late Jurassic. The superimposition of D2 on D1 recorded a significant tectonic transformation from the nearly E-W–trending Tethysian domain to the NE-SW–trending Pacific domain.

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Petrogenesis and magmatic evolution of the intermediate–felsic Early Cretaceous Shizhuzi magmatic complex on Liaodong Peninsula, NE China

Lithos ◽

10.1016/j.lithos.2021.106338 ◽

2021 ◽

pp. 106338

Author(s):

Jinjian Wu ◽

Qingdong Zeng ◽

Jinhui Yang ◽

Rui Li ◽

Bing Yu ◽

...

Keyword(s):

Early Cretaceous ◽

Magmatic Evolution ◽

Ne China ◽

Magmatic Complex ◽

Liaodong Peninsula

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Volcanism from different eruption cycles during the Early Cretaceous in the Changling fault depression of the songliao basin, NE China, and their implications for timing of lithospheric thinning

International Geology Review ◽

10.1080/00206814.2020.1864672 ◽

2020 ◽

pp. 1-21

Author(s):

Chaoyang Liu ◽

Xuanlong Shan ◽

Jian Yi ◽

Xianjun Ren ◽

Jiaoyan Han ◽

...

Keyword(s):

Early Cretaceous ◽

Songliao Basin ◽

Ne China ◽

Lithospheric Thinning

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Early Cretaceous crust–mantle interaction linked to rollback of the Palaeo-Pacific flat-subducting slab: constraints from the intermediate–felsic volcanic rocks of the northern Great Xing’an Range, NE China

Geological Magazine ◽

10.1017/s0016756821000170 ◽

2021 ◽

pp. 1-22

Author(s):

Jia-Hao Jing ◽

Hao Yang ◽

Wen-Chun Ge ◽

Yu Dong ◽

Zheng Ji ◽

...

Keyword(s):

Early Cretaceous ◽

Volcanic Rocks ◽

Geochemical Data ◽

Calc Alkaline ◽

Ne China ◽

Asthenospheric Mantle ◽

High K ◽

Wide Range ◽

Great Xing’An Range ◽

Subducting Slab

Abstract Late Mesozoic igneous rocks are important for deciphering the Mesozoic tectonic setting of NE China. In this paper, we present whole-rock geochemical data, zircon U–Pb ages and Lu–Hf isotope data for Early Cretaceous volcanic rocks from the Tulihe area of the northern Great Xing’an Range (GXR), with the aim of evaluating the petrogenesis and genetic relationships of these rocks, inferring crust–mantle interactions and better constraining extension-related geodynamic processes in the GXR. Zircon U–Pb ages indicate that the rhyolites and trachytic volcanic rocks formed during late Early Cretaceous time (c. 130–126 Ma). Geochemically, the highly fractionated I-type rhyolites exhibit high-K calc-alkaline, metaluminous to weakly peraluminous characteristics. They are enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs) but depleted in high-field-strength elements (HFSEs), with their magmatic zircons ϵHf(t) values ranging from +4.1 to +9.0. These features suggest that the rhyolites were derived from the partial melting of a dominantly juvenile, K-rich basaltic lower crust. The trachytic volcanic rocks are high-K calc-alkaline series and exhibit metaluminous characteristics. They have a wide range of zircon ϵHf(t) values (−17.8 to +12.9), indicating that these trachytic volcanic rocks originated from a dominantly lithospheric-mantle source with the involvement of asthenospheric mantle materials, and subsequently underwent extensive assimilation and fractional crystallization processes. Combining our results and the spatiotemporal migration of the late Early Cretaceous magmatic events, we propose that intense Early Cretaceous crust–mantle interaction took place within the northern GXR, and possibly the whole of NE China, and that it was related to the upwelling of asthenospheric mantle induced by rollback of the Palaeo-Pacific flat-subducting slab.

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