Early Cretaceous intermediate-mafic dykes in the Dabie orogen, eastern China: Petrogenesis and implications for crust–mantle interaction

Xu, Haijin; Ma, Changqian; Song, Yanru; Zhang, Junfeng; Yang, Kai

doi:10.1016/j.lithos.2012.06.030

Cited by 57 publications

(25 citation statements)

References 95 publications

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“…Their initial 87 Sr/ 86 Sr ratios range from 0.7074 to 0.7094 (Table 3). These isotopic characteristics are similar to those of Mesozoic volcanic rocks from the eastern of the NHY (initial 87 Sr/ 86 Sr = 0.7074-0.7098 and e Nd (t) = À16.2 to À24.2) Fan et al, 2004), Early Cretaceous mafic/ultramafic intrusions in the Dabie Orogen (Jahn et al, 1999;Huang et al, 2007;Zhao and Zheng, 2009;Xu et al, 2012) (Fig. 7).…”

Section: Whole Rock Sr-nd Isotopessupporting

confidence: 68%

“…6b), they are enriched in LILE (e.g., Rb, Ba, P and K) and depleted in Nb, Ta and Ti. These geochemical characteristics are similar to those of Early Cretaceous mafic-ultramafic plutons and intermediate-mafic dykes in the region (e.g., Jahn et al, 1999;Huang et al, 2007;Zhao and Zheng, 2009;Xu et al, 2012;Yang et al, 2012aYang et al, , 2012b (Fig. 6).…”

Section: Whole Rock Major and Trace Elementssupporting

confidence: 61%

“…As illustrated in Fig. 8, the zircon e Hf (t) values of the Jingangtai volcanic rocks match with those of granites in the Dabie Orogen Zhang et al, 2010a;Xu et al, 2013) and Early Cretaceous intermediat-mafic rocks in the Dabie Orogen (Xu et al, 2012), indicating a genetic relationship between them.…”

Section: In Situ Zircon Lu-hf Isotopic Compositionsmentioning

confidence: 59%

“…The felsic melts would react with the overlying SCLM wedge materials of the NCC, generating the fertile ultramafic metasomes that are enriched in melt-mobile incompatible trace elements and pertinent radiogenic isotopes. The orogenic SCLM , Jinan gabbros from the central NCC Guo et al, 2001), Early Cretaceous intermediatemafic dykes and mafic to ultramafic plutons in the Dabie-Sulu Orogen (Jahn et al, 1999;Li and Yang, 2003;Huang et al, 2007;Zhao and Zheng, 2009;Xu et al, 2012), mafic rocks from the NCC exterior (Fangcheng basalts, Mengyin K-rich volcanics and high-Mg diorites) (Qiu et al, 2002;Wu et al, 2003;, Mesozoic mafic rocks in the YZC Li et al, 2004); Kongling TTG rocks are from Gao et al (1999); Depleted mantle are from Sun and McDonough (1989); the NCC lower crust and YZC upper/middle crust from Jahn et al (1999). The numbers indicate the percentages of participation of the crustal materials.…”

Section: Implications For Tectonic Evolutionmentioning

confidence: 99%

“…The large-scale partial melting of the continental crust marks beginning of the extension, while the mafic-ultramafic igneous rocks and alkaline rocks demonstrate the intensive lithospheric thinning and extensional setting in the region. Xu et al, 2012;Zhang et al, 2010a); Early Cretaceous intermediat-mafic rocks in the Dabie Orogen Xu et al, 2012). Table 5.…”

Section: Implications For Tectonic Evolutionmentioning

confidence: 99%

See 4 more Smart Citations

Petrogenesis of the early Cretaceous volcanic rocks in the North Huaiyang tectono-magmatic unit of the Dabie Orogen, eastern China: Implications for crust–mantle interaction

Gao

Zhao

2016

Journal of Asian Earth Sciences

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Section: Whole Rock Sr-nd Isotopessupporting

confidence: 68%

Section: Whole Rock Major and Trace Elementssupporting

confidence: 61%

Section: In Situ Zircon Lu-hf Isotopic Compositionsmentioning

confidence: 59%

Section: Implications For Tectonic Evolutionmentioning

confidence: 99%

Section: Implications For Tectonic Evolutionmentioning

confidence: 99%

See 3 more Smart Citations

Petrogenesis of the early Cretaceous volcanic rocks in the North Huaiyang tectono-magmatic unit of the Dabie Orogen, eastern China: Implications for crust–mantle interaction

Gao

Zhao

2016

Journal of Asian Earth Sciences

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Source and magma mixing processes in continental subduction factory: Geochemical evidence from postcollisional mafic igneous rocks in the Dabie orogen

Dai

Zhao

Zheng

et al. 2015

Geochem. Geophys. Geosyst.

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Postcollisional mafic igneous rocks commonly exhibit petrological and geochemical heterogeneities, but their origin still remains enigmatic. While source mixing is substantial due to the crustmantle interaction during continental collision, magma mixing is also significant during postcollisional magmatism. The two processes are illustrated by Early Cretaceous mafic igneous rocks in the Dabie orogen. These mafic rocks show arc-like trace element distribution patterns and enriched Sr-Nd-Pb isotope compositions, indicating their origination from enriched mantle sources. They have variable whole-rock e Nd (t) values of 217.6 to 25.2 and zircon e Hf (t) values of 229.0 to 27.7, pointing to source heterogeneities. Such whole-rock geochemical features are interpreted by the source mixing through melt-peridotite reaction in the continental subduction channel. Clinopyroxene and plagioclase megacrystals show complex textural and compositional variations, recording three stages of mineral crystallization during magma evolution. Cpx-1 core has low Cr and Ni but high Ba, Rb and K, indicating its crystallization from a mafic melt (Melt 1) derived from partial melting of hydrous peridotite rich in phlogopite. Cpx-1 mantle and Cpx-2 exhibit significantly high Cr, Ni and Al 2 O 3 but low Rb and Ba, suggesting their crystallization from pyroxenite-derived mafic melt (Melt 2). Whole-rock initial 87 Sr/ 86 Sr ratios of gabbro lies between those of Pl-1core (crystallized from Melt 1) and Pl-1 mantle and Pl-2 core (crystallized from Melt 2), providing isotopic evidence for magma mixing between Melt 1 and Melt 2. Taken together, a heterogeneously enriched mantle source would be generated by the source mixing due to reaction of the overlying subcontinental lithospheric mantle wedge peridotite with felsic melts derived from partial melting of different rocks of the deeply subducted continental crust during the continental collision. The magma mixing would occur between mafic melts that were derived from partial melting of the heterogeneously metasomatic mantle domains in the postcollisional stage. As a consequence, the source and magma mixing processes in the continental subduction factory are responsible for the significant variations in the whole-rock and mineral geochemistries of postcollisional mafic igneous rocks.

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How did the Dabie Orogen collapse? Insights from 3‐D magnetotelluric imaging of profile data

Zhang

Griffin

et al. 2016

JGR Solid Earth

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The Dabie Orogen is a key part of the Central Orogen of China and is well known because of its exposures to high‐ and ultrahigh‐pressure metamorphic rocks. It has been proposed to have formed by continent‐continent collision between the Yangtze and North China blocks in the Middle‐to‐Late Triassic and to have collapsed in the middle of the Early Cretaceous. However, there are few signatures in the lithospheric architecture that might constrain the scale of the orogenic collapse; as a result there has been a long‐term debate on its origin. A 300 km long broadband magnetotelluric transect perpendicular to a major collapsed structure has been completed to find some possible clues to the mechanisms of the orogenic collapse. The inverted resistivity cross section from 3‐D inversion of magnetotelluric profile data refines the postcollision lithospheric structure and in particular identifies domains of refertilized and depleted lithospheric mantle and isolated midcrustal low‐velocity and high‐conductivity zones. A correlation between voluminous surface magmatism in the Early Cretaceous and deep refertilized lithospheric mantle is illuminated by elevated electrical conductivity. We suggest that the lowermost crust was removed by delamination beneath the eastern Dabie during the orogenic collapse, while beneath the Tongbai‐Xinyang Terrain residual cratonic crust is underlain by depleted lithospheric mantle with relatively high resistivity. The isolated low‐velocity and high‐conductivity zones in the middle crust have been ascribed to shear‐promoted graphitic films which were destroyed by local granitic intrusions around 134 to 125 Ma. This lithospheric process can be attributed to far‐field effects, such as refertilization in the lower lithospheric mantle, promoted by upwelling of the asthenosphere and related fluids, during Paleo‐Pacific subduction beneath the Euro‐Asian continent.

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Early Cretaceous intermediate-mafic dykes in the Dabie orogen, eastern China: Petrogenesis and implications for crust–mantle interaction

Cited by 57 publications

References 95 publications

Petrogenesis of the early Cretaceous volcanic rocks in the North Huaiyang tectono-magmatic unit of the Dabie Orogen, eastern China: Implications for crust–mantle interaction

Petrogenesis of the early Cretaceous volcanic rocks in the North Huaiyang tectono-magmatic unit of the Dabie Orogen, eastern China: Implications for crust–mantle interaction

Source and magma mixing processes in continental subduction factory: Geochemical evidence from postcollisional mafic igneous rocks in the Dabie orogen

How did the Dabie Orogen collapse? Insights from 3‐D magnetotelluric imaging of profile data

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