scholarly journals Geochemical Evidence for Thickening and Thinning of Lower Crust beneath the Jiaodong Peninsula: Implications for Late Mesozoic Destruction of the Eastern North China Craton

Lithosphere ◽  
2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
YaYun Liang ◽  
Wenhui Guo ◽  
Yao Ma ◽  
Enquan Zhao
Keyword(s):  
Continental Crust ◽  
Early Cretaceous ◽  
North China Craton ◽  
Late Jurassic ◽  
North China ◽  
Temporal Variations ◽  
Late Mesozoic ◽  
Jiaodong Peninsula ◽  
Intrusive Rocks ◽  
Subducting Slab

Abstract The eastern North China Craton (NCC) has been recognised as undergoing cratonic destruction during the Mesozoic; however, the mechanism of its destruction is still unclear. The main difference between the proposed models is whether the lower continental crust (LCC) underwent thinning. In this study, we conducted comprehensive analyses of Late Mesozoic felsic intrusive rocks, including Late Jurassic granites (166–146 Ma), Early Cretaceous granodiorites (136–123 Ma), and latest Early Cretaceous granites (123–108 Ma) from the Jiaodong Peninsula, located on the southeastern margin of the NCC. These rocks allowed us to investigate variations in the LCC thickness in this region and to further discuss the destruction mechanism of the eastern NCC. Here, temporal variations in crustal thickness can be tracked using whole-rock La/Yb ratios of the felsic intrusive rocks. Our study shows that the continental crust in the eastern NCC thickened during the Late Jurassic (>40 km) due to compression and the westward subduction of the Palaeo-Pacific Ocean lithosphere beneath the NCC since the Early Jurassic. The continental crust further thickened during the Early Cretaceous, caused by the steepening of the subducting slab after ~144 Ma that produced crustal underplating of mantle-derived melts in an extensional setting. However, the continental crust thinned (20–40 km) during the latest Early Cretaceous, caused by the rollback of the subducting slab after ~123 Ma. The geochemical compositions of three stages of felsic intrusions also suggest that the regional tectonic stress that affects the eastern NCC altered from a compressional to an intraplate extensional environment after ~144 Ma. Thus, the Late Mesozoic destruction of the eastern NCC and its accompanying magmatism were controlled by prolonged thermomechanical-chemical erosion due to low-angle subduction, steepening, and rollback of the Palaeo-Pacific Oceanic lithosphere.

Contrasting Middle Jurassic and Early Cretaceous mafic intrusive rocks from western Liaoning, North China craton: petrogenesis and tectonic implications

2010 ◽  
Vol 147 (6) ◽  
pp. 844-859 ◽  
Author(s):  
XIAOHUI ZHANG ◽  
HONGFU ZHANG ◽  
NENG JIANG ◽  
SIMON A. WILDE
Keyword(s):  
Trace Element ◽  
Early Cretaceous ◽  
North China Craton ◽  
Middle Jurassic ◽  
North China ◽  
Stability Field ◽  
Rock Interaction ◽  
Western Liaoning ◽  
Late Mesozoic ◽  
Intrusive Rocks

AbstractZircon U–Pb dating, whole-rock major oxide, trace element and Sr–Nd isotopic data are presented for the Late Mesozoic mafic intrusive rocks from Yiwulüshan of western Liaoning along the eastern segment of the Yanshan belt, North China craton, with two episodes of magmatism documented. Middle Jurassic hornblende-rich gabbros show enrichment of large ion lithophile elements and light REE, and prominent depletion in high field strength elements, and possess moderately enriched isotopic compositions with (87Sr/86Sr)i ranging from 0.7056 to 0.7065 and ɛNd(t) from −5.0 to −7.1. These features suggest that the gabbros were derived from an amphibole-bearing harzburgitic lithospheric mantle source metasomatized recently by slab-derived fluids. By contrast, Early Cretaceous mafic dykes are gabbroic dioritic to dioritic in composition, with comparable trace element characteristics to continental crust and depleted isotopic signatures ((87Sr/86Sr)i = 0.7048–0.7055, ɛNd(t) = 0 to −3.0). They probably originated from partial melting of a relatively fertile asthenospheric mantle in the spinel stability field, with subsequent lower crustal assimilation and fractional crystallization. These two contrasting mafic intrusive suites, together with multiple Mesozoic mafic volcanic rocks from western Liaoning, documented a localized lithospheric thinning process, mainly through prolonged hydro-weakening or melt–rock interaction and triggered by gravitational collapse, possibly within an evolved post-collisional to within-plate extensional regime.

Late Mesozoic magmatism and sedimentation in the Jiaodong Peninsula: New constraints on lithospheric thinning of the North China Craton

Lithos ◽  
2018 ◽  
Vol 322 ◽  
pp. 312-324 ◽  
Author(s):  
Rui Zhao ◽  
Qingfei Wang ◽  
Jun Deng ◽  
M. Santosh ◽  
Xuefei Liu ◽  
...  
Keyword(s):  
North China Craton ◽  
North China ◽  
Late Mesozoic ◽  
Lithospheric Thinning ◽  
The North ◽  
Jiaodong Peninsula ◽  
Mesozoic Magmatism

Uplift history of the Jiaodong Peninsula, eastern North China Craton: implications for lithosphere thinning and gold mineralization

2017 ◽  
Vol 155 (4) ◽  
pp. 979-991 ◽  
Author(s):  
RUI ZHAO ◽  
QINGFEI WANG ◽  
XUEFEI LIU ◽  
M. SANTOSH ◽  
WANMING YUAN ◽  
...  
Keyword(s):  
North China Craton ◽  
North China ◽  
Gold Mineralization ◽  
Gold Deposits ◽  
Late Mesozoic ◽  
Lithosphere Thinning ◽  
Jiaodong Peninsula ◽  
History Of ◽  
Timing Of Initiation ◽  
Two Stages

AbstractThe link between lithosphere thinning and formation of world-class gold deposits is well established in the Jiaodong Peninsula within the eastern North China Craton (NCC). However, the timing of initiation and duration of the lithospheric thinning process as well as the depth of formation of the mineralization remain uncertain. Since these parameters are fundamental to formulate exploration strategies, in this study we perform fission track (FT) analysis on zircon and apatite grains in Late Mesozoic granitoid samples from the Jiaodong Peninsula and provide new constraints for the mode and duration of lithospheric evolution and mineralization depth. The zircon FT ages range from 64.3 to 90.9 Ma and those of apatite show a range of 32.8–50.9 Ma. The data collectively display age peaks at ~60–80 and ~30–50 Ma. Reverse modelling of the apatite FT results indicates rapid crustal uplift during ~30–80 Ma in the Jiaodong Peninsula. This period coincides with the timing of maximal sedimentation in the neighboring basins and voluminous basaltic eruptions in the eastern NCC. We suggest that the Jiaodong Peninsula has experienced two stages of crust uplift in the Late Cretaceous and Paleogene as a consequence of the continuing lithosphere thinning, together with the surrounding basins, forming the horst–graben system in the eastern NCC. The Late Mesozoic granitoids are the main wall rocks for gold deposits in Jiaodong, and thus the crust denudation history gathered from the FT data suggest that the gold mineralization formed at depths of c. 6–11 km.

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