Magma-derived CO 2 emissions in the Tengchong volcanic field, SE Tibet: Implications for deep carbon cycle at intra-continent subduction zone

Zhang, Maoliang; Guo, Zhengfu; Sano, Yuji; Zhang, Lihong; Sun, Yujun; Cheng, Zhongjun; Yang, Tsanyao Frank

doi:10.1016/j.jseaes.2016.06.009

Cited by 41 publications

(43 citation statements)

References 128 publications

(193 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The network of karstic voids/caves and fissures below VC would favour the diffusion and convection of deep-endogenous gases to the upper layers of the aquifer, including the polygenic conglomerates hosting VC. Similar carbon isotopic ratios have been described for soil air samples from hydrothermal areas within wider volcanic regions [27] and magma-derived CO 2 emissions [28]. Other studies at hydrothermal sites have described wider ranges of carbon isotope composition of CO 2 (e.g., from −2.4 to −7.8‰ in submarine hydrothermal vents [29] and from −1.0 to −9.1‰ in hot springs [30]).…”

Section: Co 2 (Ppm)supporting

confidence: 71%

Geochemical Fingerprinting of Rising Deep Endogenous Gases in an Active Hypogenic Karst System

et al. 2018

View full text Add to dashboard Cite

The hydrothermal caves linked to active faulting can potentially harbour subterranean atmospheres with a distinctive gaseous composition with deep endogenous gases, such as carbon dioxide (CO2) and methane (CH4). In this study, we provide insight into the sourcing, mixing, and biogeochemical processes involved in the dynamic of deep endogenous gas formation in an exceptionally dynamic hypogenic karst system (Vapour Cave, southern Spain) associated with active faulting. The cave environment is characterized by a prevailing combination of rising warm air with large CO2 outgassing (>1%) and highly diluted CH4 with an endogenous origin. The δ13CCO2 data, which ranges from −4.5 to −7.5‰, point to a mantle-rooted CO2 that is likely generated by the thermal decarbonation of underlying marine carbonates, combined with degassing from CO2-rich groundwater. A pooled analysis of δ13CCO2 data from exterior, cave, and soil indicates that the upwelling of geogenic CO2 has a clear influence on soil air, which further suggests a potential for the release of CO2 along fractured carbonates. CH4 molar fractions and their δD and δ13C values (ranging from −77 to −48‰ and from −52 to −30‰, respectively) suggest that the methane reaching Vapour Cave is the remnant of a larger source of CH4, which was likely generated by microbial reduction of carbonates. This CH4 has been affected by a postgenetic microbial oxidation, such that the gas samples have changed in both molecular and isotopic composition after formation and during migration through the cave environment. Yet, in the deepest cave locations (i.e., 30 m below the surface), measured concentration values of deep endogenous CH4 are higher than in atmospheric with lighter δ13C values with respect to those found in the local atmosphere, which indicates that Vapour Cave may occasionally act as a net source of CH4 to the open atmosphere.

show abstract

Section: Co 2 (Ppm)supporting

confidence: 71%

Geochemical Fingerprinting of Rising Deep Endogenous Gases in an Active Hypogenic Karst System

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In Figure 6(b), the 3 He/ 4 He values of the studied samples within the mixing curves (Figure 6(a)) are negatively correlated with CO 2 / 3 He ratios (R 2 = 0 587), further supporting the mixing between DMM or EM end member (both with high-R A and low-CO 2 / 3 He ratios) and subducted slab materials (CAR/ORS end member with low-R A and high-CO 2 / 3 He ratios) [67]. However, these samples are obviously located away from the above mixing line (Figure 5(b)), which shows a binary mixing trend between EM-derived volatiles [35]). The 3 He/ 4 He (R A ) ratios of CAR and ORS end members are assumed to be 0 02R A [66] and the CO 2 / 3 He values ranging from 10 12 to 10 14 [62].…”

Section: Geofluidsmentioning

confidence: 53%

“…Soil CO 2 fluxes were measured in situ using soil diffuse gas flux meters based on the accumulation chamber method (Figure 2(d)), which was firstly reported by Chiodini et al [34]. The edge of the inverted cylindrical chamber was sealed with damp soil to diminish air contamination of the soil gases in the chamber [35]. The measurement sites were located near the main volcano-structural features of the region and preferentially placed on uncovered ground to minimize the influence of the vegetation on the measured fluxes (Figure 1(c)).…”

Section: Sampling and Analytical Methodsmentioning

confidence: 99%

“…The diagram of 3 He/ 4 He (R A ) versus CO 2 / 3 He ratios of volcanic or hydrothermal volatiles has provided important constraints on the origin of carbon [35,61]. In Figure 6(b), the 3 He/ 4 He values of the studied samples within the mixing curves (Figure 6(a)) are negatively correlated with CO 2 / 3 He ratios (R 2 = 0 587), further supporting the mixing between DMM or EM end member (both with high-R A and low-CO 2 / 3 He ratios) and subducted slab materials (CAR/ORS end member with low-R A and high-CO 2 / 3 He ratios) [67].…”

Section: Geofluidsmentioning

confidence: 99%

See 1 more Smart Citation

Volcanogenic CO₂ Degassing in the Songliao Continental Rift System, NE China

et al. 2019

Self Cite

View full text Add to dashboard Cite

The Wudalianchi monogenetic volcanic field (WMVF) is located in the Songliao basin within a major continental rift system in NE China. Bubbling springs and diffuse degassing from soils are typical features of the WMVF. Chemical compositions and C-He isotope analyses revealed that the cold spring gases might originate from the enriched upper mantle (EM), which resulted from the mixing between slab materials (subducted organic sediments and carbonates) in the mantle transition zone (MTZ) and the ambient depleted mantle. These EM-derived volatiles experienced variable degrees of crustal input, including both continental organic metasediments and crustal carbonates during their ascending path to the surface. The estimated results of the degassing CO2 fluxes, combined with previous geophysical evidence, suggest that the CO2 degassing activities become weaker from early to late in Quaternary.

show abstract

“…Geological gases such as SO2 and CO2 being linked to subsurface processes are quantitative indicators of Earth's geochemical and geomechanical activity [1][2][3][4]. Magmatic CO2, for instance, is a viable tracer of periods of volcanic unrest [5][6][7].…”

mentioning

confidence: 99%

Portable laser spectrometer for airborne and ground-based remote sensing of geological CO_2 emissions

et al. 2017

View full text Add to dashboard Cite

A 24 kg, suitcase sized, CW laser remote sensing spectrometer (LARSS) with a ~2 km range has been developed. It has demonstrated its flexibility in measuring both atmospheric CO₂ from an airborne platform and terrestrial emission of CO₂ from a remote mud volcano, Bledug Kuwu, Indonesia, from a ground-based sight. This system scans the CO₂ absorption line with 20 discrete wavelengths, as opposed to the typical two-wavelength online offline instrument. This multi-wavelength approach offers an effective quality control, bias control, and confidence estimate of measured CO₂ concentrations via spectral fitting. The simplicity, ruggedness, and flexibility in the design allow for easy transportation and use on different platforms with a quick setup in some of the most challenging climatic conditions. While more refinement is needed, the results represent a stepping stone towards widespread use of active one-sided gas remote sensing in the earth sciences.

show abstract

Magma-derived CO 2 emissions in the Tengchong volcanic field, SE Tibet: Implications for deep carbon cycle at intra-continent subduction zone

Cited by 41 publications

References 128 publications

Geochemical Fingerprinting of Rising Deep Endogenous Gases in an Active Hypogenic Karst System

Geochemical Fingerprinting of Rising Deep Endogenous Gases in an Active Hypogenic Karst System

Volcanogenic CO₂ Degassing in the Songliao Continental Rift System, NE China

Portable laser spectrometer for airborne and ground-based remote sensing of geological CO_2 emissions

Contact Info

Product

Resources

About

Magma-derived CO 2 emissions in the Tengchong volcanic field, SE Tibet: Implications for deep carbon cycle at intra-continent subduction zone

Cited by 41 publications

References 128 publications

Geochemical Fingerprinting of Rising Deep Endogenous Gases in an Active Hypogenic Karst System

Geochemical Fingerprinting of Rising Deep Endogenous Gases in an Active Hypogenic Karst System

Volcanogenic CO2 Degassing in the Songliao Continental Rift System, NE China

Portable laser spectrometer for airborne and ground-based remote sensing of geological CO_2 emissions

Contact Info

Product

Resources

About

Volcanogenic CO₂ Degassing in the Songliao Continental Rift System, NE China