Study of thrust and nappe tectonics in the eastern Jiaodong Peninsula, China

Abstract

Thrust and nappe tectonics have affected the eastern Jiaodong Peninsula, the easternmost terminal of the Sulu Ultra-high Pressure Metamorphic Belt. Four nappes have been mapped, named respectively the Shidao, Rongcheng, Mishan and Mouping nappes. The methods used included multi-scale structural analysis and structural chronology analysis. These nappes define four deep level slip-thrust shear zones that were mainly active in the Mesozoic. The amount of ductile deformation decreases from the Shidao to Rongcheng to Mouping to Mishan shear zones, and shows an inverse relationship with temperature. 40 Ar/ 39 Ar chronological analysis and the chronological results of former workers reveal four movement steps defined by the development of thrusts and nappes in the late Triassic (210-180 Ma), extensional movement from the Jurassic to early Cretaceous (180-130 Ma), slip-thrust movement in the Early Cretaceous (130-120 Ma), and extensional movement since the Late Cretaceous (120 Ma). The order of boundary shear zone motion in the period of slip-thrust movement during the Early Cretaceous (130-120 Ma) was along the Shidao, Rongcheng, Mouping and finally the Mishan shear zone. This resulted in clockwise rotation of the nappes relative to block west to the Tan-Lu Faults. Because of the similar evolutionary history of the Tan-Lu Faults and the thrust and nappe structure in the eastern Jiaodong Peninsula, slip dislocation along the Tan-Lu Faults might have been absorbed by thrust and nappe tectonics in the Jiaodong area in the Mesozoic era, resulting in much less dislocation on the Tan-Lu faults in North Eastern China than that in south along the Jiaodong Peninsula.

The Mesozoic Tectonic Dynamics and Chronology in the Eastern North China Block

“…The collision between the Yangtze block and the NCB began at Middle-Late Triassic, the Dabie-Sulu ultrahigh pressure metamorphic belt was formed at 242-224 Ma and cooled down to 300 • C at 180 Ma [8,9], which is approximately consistent with the early deformation age of ductile shear zone in Dabie-Sulu orogenic belt (Ar-Ar age of ∼190 Ma, Tables 1 and 2, [11,18]). Perhaps it was the geological record of orogenic relaxation at about 180-190 Ma, indicating the ending of collision orogenesis.…”

“…The Shidao shear zone is a broad ductile shear zone (>15 km in width) thrusting toward north and sinistral strike slipping in ENE-WSW direction. The total shear displacement is more than 90 km, in which the strike displacement is at least 19 km, the thrusting displacement >88 km, and the horizontal shrinkage >85 km, horizontal shrinkage ration about 68% [18]. If Rongcheng, Mishan, and Mouping nappes were taken as an entirety, it turned about 25 • clockwise (Figure 4), similar to the Korea peninsula which turned 30.5 • clockwise [19].…”

Structural anatomy of the exhumation of high‐pressure rocks: constraints from the Tongbai Collisional Orogen and surrounding units

“…The rate of oblique extrusion is still unclear from the available data. The WNW-ESE trending horizontal stretching lineation associated with the initial exhumation of the HP-UHP rocks also developed in the Dabie-Sulu Orogen Ratschbacher et al, 2000;Zhang et al, 2007;Xiang et al, 2008;Li et al, 2009a). Ongoing eastward extrusion of HP rocks led to thinning and breakoff of the subducting plate.…”

Episodic Crustal Extension and Contraction Characterizing the Late Mesozoic Tectonics of East China: Evidence From the Jiaodong Peninsula, East China

“…Muscovite and biotite yielded 128-126 Ma and 124-120 Ma 40 Ar/ 39 Ar ages for the mylonitic Q granite (Figure 4c; J. W. Li et al, 2006;L. Wu, 2014;H. Y. Zhang et al, 2007).…”

“… Available geochronological data of the QKYS massif. Date are from W. Chen et al., (1992); Goss et al., (2010); Guo et al., (2010); Hacker et al., (2006, 2009); F. Hu et al., (2004); J. W. Li et al., (2006); F. Liu et al., (2017); L. P. Liu et al., (2017); Tang et al., (2014); L. Wu (2014); L. Wu et al., (2018); Xia et al., (2016); D. Q. Zhang et al., (1995); T. Zhang & Y. Zhang (2007, 2008); H. Y. Zhang et al., (2007); J. Zhang et al., (2010); R. Zhao et al., (2016). Legends and abbreviations are the same in Figure 2.…”