Late Cenozoic intra-plate basalts of the Greater Khingan Range in NE China and Khangai Province in Central Mongolia

Meng, Fanchao; Safonova, Inna; Chen, Shuangshuang; Rioual, Patrick

doi:10.1016/j.gr.2018.05.009

Cited by 14 publications

(2 citation statements)

References 111 publications

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“…In detail, the pre‐110 Ma mafic rocks across central and eastern Asia generally have calc‐alkaline compositions with enriched radiogenic isotopes and negative anomalies in Nb and Ta (Gao et al., 2008; Kong et al., 2019; Sheldrick, Hahn, et al., 2020; Zhang et al., 2003), and carry significant contributions from lithospheric mantle (Geng, Liu, et al., 2019; Sheldrick et al., 2018; Zhang et al., 2002). In contrast, their post‐110 Ma counterparts (Figure 1b) are characterized by alkaline compositions with depleted radiogenic isotopes and positive anomalies in Nb and Ta (Meng et al., 2018; Togtokh et al., 2018; Wu, Ling, et al., 2017; Xu et al., 2018), and are sourced directly from the asthenosphere (Barry et al., 2003; Ma et al., 2014; Menzies et al., 1993; Xu et al., 2004). It is still unclear if the coincident transition represents a ubiquitous physicochemical process operating across central and eastern Asia, especially when the sources of mantle melts appear to be so diverse.…”

Section: Introductionmentioning

confidence: 99%

Melting Dynamics of Late Cretaceous Lamprophyres in Central Asia Suggest a Mechanism to Explain Many Continental Intraplate Basaltic Suite Magmatic Provinces

et al. 2021

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Intraplate small‐volume mafic magmatism is spatially and temporally widespread in central and eastern Asia, but the relevant melting dynamics have remained enigmatic. Here, we report Ar‐Ar ages, mineral and whole‐rock compositions on newly found ∼81 Ma lamprophyre dykes from central Asia, aiming to constrain the source characteristics and the melting dynamics in this intraplate setting. Mineral chemistry of the lamprophyres shows that pre‐emplacement magmas equilibrated at 970–1060°C (probably at the base of the crust) and contained 1.4–2.1 wt% water. The source region of the lamprophyres is shown to have H contents equivalent to H2O = ∼150 ppm, and to be lithologically heterogeneous with silica‐deficient pyroxenite embedded in peridotite. Because of the thermodynamic complexities involved in calculating melting scenarios with major elements for such mantle domains, we have conducted a grid search with a forward‐modeling methodology that can simulate the adiabatic decompression melting of a lithologically heterogeneous mantle using incompatible trace elements. The modeling results indicate that original melting occurred at a potential temperature of ∼1400°C under a thinned lithosphere (∼70 km, corresponding to a final melting pressure of 2.3 GPa). Combining these conditions with constraints from regional geology and the tectonic history, the lamprophyres are inferred to have formed by decompression melting induced by small‐scale asthenospheric upwellings due to the edge effects under a corrugated lithospheric lower boundary. We suggest that this scenario has global relevance and represents a likely mechanism for the initiation of relatively small‐scale intraplate magmatism within continents.

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Section: Introductionmentioning

confidence: 99%

Melting Dynamics of Late Cretaceous Lamprophyres in Central Asia Suggest a Mechanism to Explain Many Continental Intraplate Basaltic Suite Magmatic Provinces

et al. 2021

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“…The study area is part of the Arxan-Chaihe Volcanic Field (Figure 1). It is a middle mountain area where Mesozoic basement rocks form fault-bounded ridges [9] (Figures 1 and 2). Between the ranges, broad flat-floored valleys are commonly filled with basaltic lava flows.…”

Section: Study Areamentioning

confidence: 99%

Geodiversity Elements of a Young Fissure System as an Immediate Precursory Event of the Youngest Fissure-Fed Eruption within the Arxan UNESCO Global Geopark, Inner Mongolia, NE China

Németh

2022

Iecg 2022

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The Arxan-Chaihe Volcanic Field (ACVF) is a Pliocene to Recent intracontinental monogenetic volcanic field. Within the ACVF are preserved at least 47 vents in a ~2000 km2 area, forming two major NE-SW trending structural elements. The youngest eruptions took place about 2000 B.P., forming two distinct complex scoriaceous and lava spatter cone systems emitting low viscosity lava that invaded the paleo-Halaha River tributary, forming pahoehoe flow fields. This lava field forms the backbone of the geoheritage values of the Arxan UNESCO Global Geopark. The lava flow fields were believed to be almost exclusively sourced from a single vent complex around the Yanshan -Gaoshan region. However, a recent study has revealed that the flow field is a result of complex eruptions with an early phase from the nearby Dahei Gou vent complex. Here we provide evidence, based on Sentinel satellite imagery, ALOS-PALSAR-derived digital terrain model analysis, and direct field observations, that an even earlier fissure-fed eruption created another complex. This can be seen as a smaller lava flow field on the western side of the main flow field. The Dichi Lake is an iconic geosite of the geopark. It is a maar crater formed by a single explosion through an earlier lava field erupted from a network of fissures ~2.5 km long following a NE-SW trend. The Dichi Lake geosite provides an ideal example demonstrating the effect of fissures opening in water-saturated lowlands resulting in phreatomagmatic eruptions. Moreover, our findings suggest that the youngest eruption in this region had at least three phases, probably not more than a few decades apart, along a 15 km-long fissure network propagated from the S.W. to N.E. We propose Dichi Lake as the centre of a geoheritage precinct, providing a hub of knowledge dissemination highlighting fissure eruptions as a key type of volcanic hazard to be taken seriously in the management of the geopark.

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Cenozoic potassic volcanic rocks from the Keluo and Wudalianchi volcanic districts, northeast China: origin from the new sub-continental lithospheric mantle (SCLM) metasomatized by potassium-rich fluids from delaminated lower crust

et al. 2022

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Late Cenozoic intra-plate basalts of the Greater Khingan Range in NE China and Khangai Province in Central Mongolia

Cited by 14 publications

References 111 publications

Melting Dynamics of Late Cretaceous Lamprophyres in Central Asia Suggest a Mechanism to Explain Many Continental Intraplate Basaltic Suite Magmatic Provinces

Melting Dynamics of Late Cretaceous Lamprophyres in Central Asia Suggest a Mechanism to Explain Many Continental Intraplate Basaltic Suite Magmatic Provinces

Geodiversity Elements of a Young Fissure System as an Immediate Precursory Event of the Youngest Fissure-Fed Eruption within the Arxan UNESCO Global Geopark, Inner Mongolia, NE China

Cenozoic potassic volcanic rocks from the Keluo and Wudalianchi volcanic districts, northeast China: origin from the new sub-continental lithospheric mantle (SCLM) metasomatized by potassium-rich fluids from delaminated lower crust

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