Geochronology, geochemistry and petrogenesis of the Dengfuxian lamprophyres: Implications for the early Cretaceous tectonic evolution of the South China Block

Liu, Biao; Wu, Jianfei; Li, Huan; Wu, Qianhong; Evans, Noreen J.; Kong, Hua; Xi, Xiao-Shuang

doi:10.1016/j.chemer.2020.125598

Cited by 12 publications

(4 citation statements)

References 104 publications

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“…Rb, Nb, Ba, REE, Th) are strongly correlated with zirconium (Fig. 14), which is highly immobile when faced with low to medium-grade metasomatic and hydrothermal phenomena (Inglis et al, 2018;Liu et al, 2020), post-magmatic influences on the Lamas de Olo lamprophyre were only moderately significant.…”

Section: Lamprophyre Petrogenesis and Source Compositionmentioning

confidence: 99%

“…Ratios of trace elements whose contents in the mantle and crust are significantly different can be used to assess possible contaminations and/or metasomatic enrichment of the mantle source (e.g. Perini et al, 2004, Kirstein et al, 2006Orejana et al, 2008;Ma et al, 2014;Soder & Romer, 2018;Liu et al, 2020). Taking into account the geochemistry of the Lamas de Olo lamprophyre, there is ample evidence for such inputs, namely the following: (i) enrichment in Ba, Th, U, and LREE; (ii) negative anomalies in Nb and Ta; (iii) high Ba/Nb ratios (117-129), which also reflect the strong alkaline signature; (iv) high La/Ta ratios (86.5-110.6); (v) low Y/Nb ratios (0.7-1.0); (vi) low Nb/U ratios (3.3-3.7); (vii) low Ce/Pb ratios (2.3-6.4); and (viii) lack of correlation between Zr and U contents (Fig.…”

Section: Lamprophyre Petrogenesis and Source Compositionmentioning

confidence: 99%

“…On the other hand, the occurrence of fractional crystallization is registered in the near-constant Th/Nb, Th/Hf, La/Sm, La/ Yb, and Ce/Yb ratios: 0.83-0.88, 3. 03-3.30, 7.07-7.11, 63.9-68.8;127.4-137.1, respectively (Allègre & Minster, 1978;Kirstein et al, 2006;Liu et al, 2020). By resorting to the composition of primitive and compositionally identical late-Variscan lamprophyre magmas (minettes) taken from the literature, an approximation to the mineral fractionation can be reasonably made.…”

Section: Lamprophyre Petrogenesis and Source Compositionmentioning

confidence: 99%

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Permo-Carboniferous hypabyssal magmatism in northern Portugal: the case of the Lamas de Olo microgranite and lamprophyre dykes

2021

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During the final stages of the Variscan orogeny, several subvolcanic dykes intruded throughout NW and SW Europe. In northern Portugal, the microgranite and lamprophyre of the Lamas de Olo region constitute a local manifestation of this magmatic event. To understand their petrogenesis, field, petrographic, and bulk-rock geochemical studies were undertaken. The lamprophyre was also analyzed for the Rb-Sr, Sm-Nd, and zircon U-Pb systematics. Mineralogically, the microgranite resembles alkali-feldspar granites, while the lamprophyre is a minette. Geochemically, the felsic dyke was probably derived from an evolved crustal source, possibly uncontaminated by mantellic or young crustal influences. The results suggest that the source is similar to that of the most evolved facies of the Lamas de Olo pluton. Structurally, the emplacement of the microgranite was presumably controlled by the regional WSW-ENE fracture system. On the other hand, lamprophyre emplacement is related to the regional NNE-SSW system. Fractional crystallization is likely to have conditioned the petrogenesis of the mafic dyke while crustal contamination probably played only a minor role. Several trace element ratios suggest that the lamprophyre resulted from low-degree melting of an enriched mantle source located in the lithospheric mantle. Source enrichment was presumably caused by subduction-related materials and metasomatism triggered by carbonate-rich fluids. When compared to other late-Variscan lamprophyres, the Lamas de Olo mafic dyke shares more similarities with the calcalkaline specimens of Western Europe. The present work corroborates previous studies concerning the hypothesis that late to post-Variscan lamprophyres may constitute a geodynamic pointer for a change in the tectonic regime.

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Section: Lamprophyre Petrogenesis and Source Compositionmentioning

confidence: 99%

Section: Lamprophyre Petrogenesis and Source Compositionmentioning

confidence: 99%

Section: Lamprophyre Petrogenesis and Source Compositionmentioning

confidence: 99%

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Permo-Carboniferous hypabyssal magmatism in northern Portugal: the case of the Lamas de Olo microgranite and lamprophyre dykes

2021

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“…This indicates that the far intracontinental E-SCB (the west of Chenzhou-Linwu Fault) is likely the center of slab break-off, consistent with the westward aging trend of exhumation timing in the intracontinental E-SCB. Other geological evidence also records a difference between the intracontinental and epicontinental E-SCB, such as the differentiated magna sources of Jurassic mafic rocks between these two areas (OIB-dominated vs. EM2) (Wang et al, 2003), contrasting metasomatized lithospheric mantle beneath the intracontinental and sub-epicontinental E-SCB (altered by slab-derived melts and fluids, respectively) (Liu et al, 2020a), and significant lithospheric differences between western and eastern sides of the 114° longitude (Yin et al, 2021). These lines of evidence further suggests that the oceanic subduction and slab break-off occurred in the Jurassic.…”

Section: Exhumation History Of the Intracontinental E-scb Since The J...mentioning

confidence: 99%

Low-temperature thermochronology data from the eastern South China Block decipher episodic subduction of the Paleo-Pacific Plate

Danišík

et al. 2021

Preprint

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Mesozoic subduction of the Paleo-Pacific Plate triggered intense tectonism, magmatism, and metallogeny in the eastern South China Block (E-SCB) and set off long-term tectonic, topographic, and climatic responses. However, contrasting hypotheses have been proposed to interpret the timing, style, and evolution of this oceanic subduction. Unraveling the exhumation history of the E-SCB is crucial to understanding deep subduction processes. To address the poorly documented exhumation history of the E-SCB, we present first zircon and apatite (U-Th)/He dates from eight Mesozoic granitoids distributed in a lateral profile across the intracontinental E-SCB. These data are combined with a compilation of regional thermochronological data, in order to address the evolution of the E-SCB in a tectonic, topographic, and climatic evolution framework. Zircon and apatite (U-Th)/He central ages of the investigated plutons range from 146-30 Ma and 82-31 Ma, respectively, implying long-lived exhumation of the intracontinental E-SCB. Inverse thermal modelling indicates the intracontinental SCB underwent multi-phase exhumation events from the Jurassic, despite variable onset timing and the fact that the far intracontinental E-SCB had been an exhumation center prior to the Early Cretaceous. In addition, a compilation map of regional thermochronological data reveals propagation of the exhumation center from the intracontinental to the epicontinental E-SCB over time (from the Cretaceous to the Paleogene). Based on these results, we propose a refined model of Paleo-Pacific Plate subduction since the Triassic. This model is in good agreement with geological observations in the E-SCB and capable of explaining regional magmatism, metallogeny, tectonism, and exhumation.Hosted file supporting information.docx available at https://authorea.com/users/529417/articles/597095low-temperature-thermochronology-data-from-the-eastern-south-china-block-decipherepisodic-subduction-of-the-paleo-pacific-plate

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Using apatite to differentiate metallogenic potential and environment of granitic rocks: A case study from the Tongshanling W-Sn-Cu-Pb-Zn ore field, Nanling Range (South China)

Förster

et al. 2023

Journal of Geochemical Exploration

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Geochronology, geochemistry and petrogenesis of the Dengfuxian lamprophyres: Implications for the early Cretaceous tectonic evolution of the South China Block

Cited by 12 publications

References 104 publications

Permo-Carboniferous hypabyssal magmatism in northern Portugal: the case of the Lamas de Olo microgranite and lamprophyre dykes

Permo-Carboniferous hypabyssal magmatism in northern Portugal: the case of the Lamas de Olo microgranite and lamprophyre dykes

Low-temperature thermochronology data from the eastern South China Block decipher episodic subduction of the Paleo-Pacific Plate

Using apatite to differentiate metallogenic potential and environment of granitic rocks: A case study from the Tongshanling W-Sn-Cu-Pb-Zn ore field, Nanling Range (South China)

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