Quantifying Non-Thermal Silicate Weathering Using Ge/Si and Si Isotopes in Rivers Draining the Yellowstone Plateau Volcanic Field, USA
Gaspard, François ; Opfergelt, Sophie ; Hirst, Catherine ; Hurwitz, Shaul ; McCleskey, R. Blaine ; Zahajská, Petra LU
; Conley, Daniel J.
LU
and Delmelle, Pierre
(2021)
In Geochemistry, Geophysics, Geosystems
22(11).
- Abstract
In active volcanic regions, high-temperature chemical reactions in the hydrothermal system consume CO2 sourced from magma or from the deep crust, whereas reactions with silicates at shallow depths mainly consume atmospheric CO2. Numerous studies have quantified the load of dissolved solids in rivers that drain volcanic regions to determine chemical weathering rates and atmospheric CO2 consumption rates. However, the balance between thermal and non-thermal components to riverine fluxes in these areas remains poorly constrained, hindering accurate estimates of atmospheric CO2 consumption rates. Here we use the Ge/Si ratio and the stable silicon isotopes (δ30Si) as tracers for... (More)
In active volcanic regions, high-temperature chemical reactions in the hydrothermal system consume CO2 sourced from magma or from the deep crust, whereas reactions with silicates at shallow depths mainly consume atmospheric CO2. Numerous studies have quantified the load of dissolved solids in rivers that drain volcanic regions to determine chemical weathering rates and atmospheric CO2 consumption rates. However, the balance between thermal and non-thermal components to riverine fluxes in these areas remains poorly constrained, hindering accurate estimates of atmospheric CO2 consumption rates. Here we use the Ge/Si ratio and the stable silicon isotopes (δ30Si) as tracers for quantifying non-thermal silicon contributions in rivers draining the Yellowstone Plateau Volcanic Field, USA. The Ge/Si ratio (µmol.mol−1) was determined for seven thermal water samples (183 ± 22), eight rivers (35 ± 23) and six creeks flowing into Yellowstone Lake (5 ± 3) during base flow and during peak water discharge following snowmelt. The δ30Si value (‰) was determined for thermal waters (−0.09 ± 0.04), Yellowstone River at Yellowstone Lake outlet (1.91 ± 0.23) and creek samples (0.82 ± 0.29). The calculated atmospheric CO2 consumption associated with non-thermal waters flowing through Yellowstone's rivers during peak discharge is ∼3.03 ton.km−2.yr−1, which is ∼2% of the annual mean atmospheric CO2 consumption in other volcanic regions. This study highlights the significance of quantifying seasonal variations in chemical weathering rates for improving estimates of atmospheric CO2 consumption rates in active volcanic regions.
(Less)
- author
- Gaspard, François
; Opfergelt, Sophie
; Hirst, Catherine
; Hurwitz, Shaul
; McCleskey, R. Blaine
; Zahajská, Petra
LU
; Conley, Daniel J.
LU
and Delmelle, Pierre
- organization
- publishing date
- 2021-11
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Ge/Si, hydrothermal, seasonal, silicon isotopes, weathering, Yellowstone
- in
- Geochemistry, Geophysics, Geosystems
- volume
- 22
- issue
- 11
- article number
- e2021GC009904
- publisher
- American Geophysical Union (AGU)
- external identifiers
-
- scopus:85119833491
- scopus:85119833491
- ISSN
- 1525-2027
- DOI
- 10.1029/2021GC009904
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2021. The Authors.
- id
- fb517783-ff97-4d1b-9978-0c87212be74f
- date added to LUP
- 2021-12-10 17:11:23
- date last changed
- 2023-02-21 10:30:14
@article{fb517783-ff97-4d1b-9978-0c87212be74f,
abstract = {{<p>In active volcanic regions, high-temperature chemical reactions in the hydrothermal system consume CO<sub>2</sub> sourced from magma or from the deep crust, whereas reactions with silicates at shallow depths mainly consume atmospheric CO<sub>2</sub>. Numerous studies have quantified the load of dissolved solids in rivers that drain volcanic regions to determine chemical weathering rates and atmospheric CO<sub>2</sub> consumption rates. However, the balance between thermal and non-thermal components to riverine fluxes in these areas remains poorly constrained, hindering accurate estimates of atmospheric CO<sub>2</sub> consumption rates. Here we use the Ge/Si ratio and the stable silicon isotopes (δ<sup>30</sup>Si) as tracers for quantifying non-thermal silicon contributions in rivers draining the Yellowstone Plateau Volcanic Field, USA. The Ge/Si ratio (µmol.mol<sup>−1</sup>) was determined for seven thermal water samples (183 ± 22), eight rivers (35 ± 23) and six creeks flowing into Yellowstone Lake (5 ± 3) during base flow and during peak water discharge following snowmelt. The δ<sup>30</sup>Si value (‰) was determined for thermal waters (−0.09 ± 0.04), Yellowstone River at Yellowstone Lake outlet (1.91 ± 0.23) and creek samples (0.82 ± 0.29). The calculated atmospheric CO<sub>2</sub> consumption associated with non-thermal waters flowing through Yellowstone's rivers during peak discharge is ∼3.03 ton.km<sup>−2</sup>.yr<sup>−1</sup>, which is ∼2% of the annual mean atmospheric CO<sub>2</sub> consumption in other volcanic regions. This study highlights the significance of quantifying seasonal variations in chemical weathering rates for improving estimates of atmospheric CO<sub>2</sub> consumption rates in active volcanic regions.</p>}},
author = {{Gaspard, François and Opfergelt, Sophie and Hirst, Catherine and Hurwitz, Shaul and McCleskey, R. Blaine and Zahajská, Petra and Conley, Daniel J. and Delmelle, Pierre}},
issn = {{1525-2027}},
keywords = {{Ge/Si; hydrothermal; seasonal; silicon isotopes; weathering; Yellowstone}},
language = {{eng}},
number = {{11}},
publisher = {{American Geophysical Union (AGU)}},
series = {{Geochemistry, Geophysics, Geosystems}},
title = {{Quantifying Non-Thermal Silicate Weathering Using Ge/Si and Si Isotopes in Rivers Draining the Yellowstone Plateau Volcanic Field, USA}},
url = {{http://dx.doi.org/10.1029/2021GC009904}},
doi = {{10.1029/2021GC009904}},
volume = {{22}},
year = {{2021}},
}