Origin of intraplate volcanism in northeast China from Love wave constraints

Abstract

The tectonic source for widespread volcanism in northeast China has not been completely understood. We develop a 3‐D SH velocity model in NE China that provides new constraints to the origin of the volcanism. The 3‐D model is constructed from fundamental mode Love waves at the periods of 20–125 s recorded at 269 broadband seismic stations. The Changbai Mountain is characterized by a significant low velocity in the lower crust and uppermost mantle, which probably results from mantle upwelling due to the subduction of the Pacific plate. A fast and thin mantle lid of ~75 km is present beneath the Songliao Basin, indicating lithosphere extension from back‐arc rifting. The slow velocity in the middle and fast velocities in the south and north at 75–115 km depths in the Songliao Basin suggest complex mantle flow with upwelling and downwelling. Unlike the other volcanic fields (Changbaishan volcano, Jingpohu volcano, and Abaga volcano), the Halaha volcano has high velocity in the lower crust and upper mantle, implying a limited melt supply from mantle source recently. The subduction‐induced upwelling leads to complicated small‐scale mantle convection, which is responsible for the intraplate magmatism in northeast China.

Shear‐Wave Velocity Structure Beneath Northeast China From Joint Inversion of Receiver Functions and Rayleigh Wave Phase Velocities: Implications for Intraplate Volcanism

“…The 3D seismic velocity model derived in this study is consistent with previous surface‐wave tomographic studies (e.g., Chen et al., 2021; Fan & Chen, 2019; Fu et al., 2016; Guo et al., 2016; Liu et al., 2017; Yang et al., 2019). For example, Fan and Chen (2019) reported a velocity reduction within the lower crust under the CBM.…”

“…However, neither our model nor most other seismic investigations corroborate such a thick lithosphere below the SLB. A recent P wave traveltime tomographic study (Jia et al., 2021) failed to detect the thin, high‐velocity lithosphere beneath the SLB, however, there is ample evidence from our study and a brunch of previous works (e.g., Fan & Chen, 2019; Fan et al., 2021; Fu et al., 2016; Li et al., 2012).…”

Seismic Structure of the Changbai Intraplate Volcano in NE China From Joint Inversion of Ambient Noise and Receiver Functions

“…Love‐wave inversion results show a notable low‐V zone at the bottom of the crust and the uppermost mantle beneath the Changbai volcano (Fu et al, ), suggesting the existence of a channel for magma migration beneath the volcano. The magmatic channel in the upper mantle beneath Changbai is not obvious in the previous ambient‐noise results (Kim et al, ; Wang & Chen, ).…”

Seismic Constraints on the Magmatic System Beneath the Changbaishan Volcano: Insight Into its Origin and Regional Tectonics

“…More recently, Guo et al () reported that the mantle upwelling beneath the CBV originates from the mantle transition zone and extends up to ~60 km below the surface, triggering the downwelling beneath the southern Songliao Basin to form small‐scale sublithospheric mantle convection. Large‐scale geophysical studies have yielded some fruitful results that commonly suggest that a deep source ascending from the mantle is responsible for the surface volcanism in the CBV (e.g., Fu et al, ; Guo et al, , ; Lei & Zhao, ; Tang et al, ; Zhao et al, ). These large‐scale seismic investigations image deep structures well beneath the CBV but lack fine resolution in shallow lithospheric structures.…”