A Large Magma Reservoir Beneath the Tengchong Volcano Revealed by Ambient Noise Adjoint Tomography

Abstract

The Tengchong volcano (TCV), situated in the west of the southeastern Tibetan Plateau, is one of the largest active volcanoes in China (Figure 1a). The TCV is characterized by large-volume magmatic gases (CO 2 and sulfide) emission (C.

Elongated Magma Plumbing System Beneath the Coso Volcanic Field, California, Constrained by Seismic Reflection Tomography

“…We conservatively set the aspect ratio as 0.1, which produces a ∼2.6% basaltic melt fraction (details of the calculation can be found in Text S2 in Supporting Information S1). Comparing the size and magnitude of the lower crustal basaltic magma reservoir with other volcanoes having similar features, such as the Tengchong (Zhao et al, 2021) or Yellowstone (Huang et al, 2015), we infer that the presence of a basaltic magma reservoir in the lower crust may be a typical feature for compositionally bimodal volcanic systems. Given the smaller size of the magma reservoir beneath the CVF compared to the Yellowstone, we consider that the present-day CVF may represent a nascent magmatic system which has a potential of developing into a large silicic magmatic system.…”

“…Then its total volume is estimated to be ∼5,200 km 3 . A two‐phase medium including mafic granulite and basaltic melt is further involved to determine the melt fraction in the lower crust (Huang et al., 2015; Zhao et al., 2021). The average P wave velocity within the basaltic magma reservoir is about 6.40 km/s.…”

Crustal and Upper Mantle Velocity Structure of SE Tibet From Joint Inversion of Rayleigh Wave Phase Velocity and Teleseismic Body Wave Data

“…Even though this feature is on the edge of the study area, the many stations located around it provide extremely dense ray coverage across the region (Figure S1 in Supporting Information S1) and the checkerboard resolution tests for ANT at periods of 8–30 s show that anomalies smaller than 0.5° × 0.5° in size can be well recovered in this edge region (Figure S2 in Supporting Information S1), further demonstrating the reliability of this feature. The isolated crustal LVZ of C, mostly beneath the Tengchong volcanic zone, likely indicates a separate magma reservoir in the mid‐lower crust that could be sourced from the deeper reservoir in the top of upper mantle (Y. Zhao et al., 2021), where significant velocity reductions present in our model. Both petrological and geochemical signatures of volcanic rocks and melt inclusions around the Tengchong volcano indicate their origin from melting of an enriched mantle (F. Chen et al., 2002; Duan et al., 2019; Zhou et al., 2012).…”

“…The isolated crustal LVZ of C, mostly beneath the Tengchong volcanic zone, likely indicates a separate magma reservoir in the mid-lower crust that could be sourced from the deeper reservoir in the top of upper mantle (Y. Zhao et al, 2021), where significant velocity reductions present in our model. Both petrological and geochemical signatures of volcanic rocks and melt inclusions around the Tengchong volcano indicate their origin from melting of an enriched mantle (F. Chen et al, 2002;Duan et al, 2019;Zhou et al, 2012).…”

Review of deep fluids in sedimentary basins and their influence on resources, with a focus on oil and geothermal exploitation

“…Three-dimensional resistivity inversion of the lower crust and deeper in the Tengchong Volcanic Area shows that there is a large basaltic magma reservoir with a volume of about 7,000 km 3 in the lower crust (20-35 km depth). The deep crust magma reservoir is supplied by the partial melting of the uppermost mantle, and the shallow magma chamber is supplied by the lower crust magma reservoir (Zhao et al, 2021). The existence of shallow magma chamber not only provides heat source for high-temperature geothermal resources in the Tengchong area, but also provides a possibility for the existence of supercritical geothermal resources in the Tengchong area (Wang et al, 2022).…”