δ26Mg, δ44Ca and 87Sr/86Sr isotope ratios constrain Mg and Ca input-output mass balances in a heavily acidified headwater catchment

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F24%3A10169426" target="_blank" >RIV/00025798:_____/24:10169426 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11310/24:10488914 RIV/00216208:11320/24:10488914

Result on the web

<a href="https://doi.org/10.1186/s12302-024-01027-z" target="_blank" >https://doi.org/10.1186/s12302-024-01027-z</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1186/s12302-024-01027-z" target="_blank" >10.1186/s12302-024-01027-z</a>

Result language

angličtina

Original language name

δ26Mg, δ44Ca and 87Sr/86Sr isotope ratios constrain Mg and Ca input-output mass balances in a heavily acidified headwater catchment

Original language description

A Central European catchment underlain by base-poor orthogneiss was studied using mass budgets and Mg-Ca-Sr isotope systematics. For 50 years, the catchment received large amounts of partly soluble dust from a nearby cluster of coal-burning power plants, while suffering from acid rain and severe spruce die-back. Our objective was to investigate to what extent anthropogenic dust contributes to Mg and Ca in runoff and to identify fractionations affecting Mg and Ca isotope composition of 13 ecosystem pools and fluxes. We hypothesized that if Mg and Ca runoff fluxes were significantly larger than their atmospheric inputs, Mg and Ca isotope ratios in runoff would converge to those of bedrock Mg and Ca. This relationship could be obscured by isotope fractionations. Strontium characterized by negligible isotope fractionations served as a Ca proxy. There was a strong positive correlation between Mg and Ca fluxes via spruce throughfall and catchment runoff. Monitoring of rainfall, canopy throughfall and runoff fluxes revealed a 20-, 15- and 15-fold excess of Mg, Ca and Sr in runoff, respectively, compared to atmospheric deposition fluxes. This sizeable excess per se would indicate predominance of geogenic base cations in runoff. The behavior of Mg and Ca isotopes was de-coupled. Petrographic study indicated that 92% of bedrock Mg was bound to easily dissolving biotite, 97% Ca was present in plagioclase, and nearly all Sr was in orthoclase. While Mg isotope ratios in bedrock and runoff were indistinguishable, corroborating predominantly geogenic Mg in runoff, Ca and Sr isotope ratios in bedrock and runoff were significantly different, consistent with a non-negligible contribution of atmospheric Ca and Sr to runoff. Previous study of sites underlain by felsic rocks indicated that the delta 44Ca value of apatite was often higher than the delta 44Ca value of plagioclase. Should weathering of apatite and/or plagioclase preferentially release Ca that is isotopically heavier than bulk rock, the geogenic Ca source at JEZ would converge to the mean delta 44Ca value of runoff. Calcium isotope data would then become more consistent with a major role of geogenic Ca in JEZ runoff indicated by mass balance data.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10511 - Environmental sciences (social aspects to be 5.7)

Project

<a href="/en/project/GA21-27420S" target="_blank" >GA21-27420S: Controls of Mg, Ca and Sr isotope signals in catchment runoff: A multiple-site approach</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

ENVIRONMENTAL SCIENCES EUROPE

ISSN

2190-4707

e-ISSN

2190-4715

Volume of the periodical

36

Issue of the periodical within the volume

1

Country of publishing house

DE - GERMANY

Number of pages

13

Pages from-to

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UT code for WoS article

001370650500001

EID of the result in the Scopus database

2-s2.0-85211138670