Changing isotope compositions of Mg, Ca and Sr in bulk crystalline rocks toward the weathering front: Disentangling inputs of geogenic base cations into ecosystems

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F25%3A10169717" target="_blank" >RIV/00025798:_____/25:10169717 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/25:10506307 RIV/00216208:11320/25:10506307

Výsledek na webu

<a href="https://doi.org/10.1016/j.apgeochem.2025.106577" target="_blank" >https://doi.org/10.1016/j.apgeochem.2025.106577</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.apgeochem.2025.106577" target="_blank" >10.1016/j.apgeochem.2025.106577</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Changing isotope compositions of Mg, Ca and Sr in bulk crystalline rocks toward the weathering front: Disentangling inputs of geogenic base cations into ecosystems

Popis výsledku v původním jazyce

Quantification of geogenic inputs of magnesium (Mg) and calcium (Ca) as essential nutrients, and strontium (Sr) as a Ca proxy, into biomass and catchment runoff is indispensable for studies of forest sustainability in an era of persisting acidification and climatic change. Supergene processes control the isotope composition of base cations released from bedrock into solution. Isotope signatures of dissolved Mg2+, Ca2+ and Sr2+ are complementary to the isotope composition of weathered rock because both are derived from the same parent material. We investigated shifts in S26Mg, S44Ca, and 87Sr/86Sr isotope ratios from fresh bedrock toward the weathering front in six common crystalline lithologies, including leucocratic granite, quartz diorite, melasyenite, melagranite, augen gneiss and amphibolite. About 20 cm below the deepest soil horizon, the isotopic composition of Mg, Ca and Sr in weathered rock differed significantly from that of fresh rock in nine out of 18 cases. Bulk-rock S26Mg and S44Ca values were less sensitive to partial dissolution of minerals than 87Sr/86Sr ratios. Statistically significant shifts in 87Sr/86Sr were observed in all six lithologies. Weathered rock had higher 87Sr/86Sr ratios than fresh rock in three cases, and lower 87Sr/86Sr ratios in another three cases. The site-specific 87Sr/86Sr shift was explained by contrasting weathering rates of Rb-rich and Rb-poor minerals in most rocks. Both lower S26Mg and higher S44Ca values of weathered amphibolite were likely related to isotope fractionations accompanying in-situ formation of secondary smectite. Continuing mineral dissolution in overlaying soils may cause additional Mg, Ca and Sr isotope effects.

Název v anglickém jazyce

Changing isotope compositions of Mg, Ca and Sr in bulk crystalline rocks toward the weathering front: Disentangling inputs of geogenic base cations into ecosystems

Popis výsledku anglicky

Quantification of geogenic inputs of magnesium (Mg) and calcium (Ca) as essential nutrients, and strontium (Sr) as a Ca proxy, into biomass and catchment runoff is indispensable for studies of forest sustainability in an era of persisting acidification and climatic change. Supergene processes control the isotope composition of base cations released from bedrock into solution. Isotope signatures of dissolved Mg2+, Ca2+ and Sr2+ are complementary to the isotope composition of weathered rock because both are derived from the same parent material. We investigated shifts in S26Mg, S44Ca, and 87Sr/86Sr isotope ratios from fresh bedrock toward the weathering front in six common crystalline lithologies, including leucocratic granite, quartz diorite, melasyenite, melagranite, augen gneiss and amphibolite. About 20 cm below the deepest soil horizon, the isotopic composition of Mg, Ca and Sr in weathered rock differed significantly from that of fresh rock in nine out of 18 cases. Bulk-rock S26Mg and S44Ca values were less sensitive to partial dissolution of minerals than 87Sr/86Sr ratios. Statistically significant shifts in 87Sr/86Sr were observed in all six lithologies. Weathered rock had higher 87Sr/86Sr ratios than fresh rock in three cases, and lower 87Sr/86Sr ratios in another three cases. The site-specific 87Sr/86Sr shift was explained by contrasting weathering rates of Rb-rich and Rb-poor minerals in most rocks. Both lower S26Mg and higher S44Ca values of weathered amphibolite were likely related to isotope fractionations accompanying in-situ formation of secondary smectite. Continuing mineral dissolution in overlaying soils may cause additional Mg, Ca and Sr isotope effects.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA21-27420S" target="_blank" >GA21-27420S: Mechanismy určující izotopové složení Mg, Ca a Sr v odtoku z malých povodí: srovnání kontrastních lokalit</a><br>

Návaznosti

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

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Applied Geochemistry

ISSN

0883-2927

e-ISSN

1872-9134

Svazek periodika

193

Číslo periodika v rámci svazku

106577

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

13

Strana od-do

nestránkováno

Kód UT WoS článku

001590535700001

EID výsledku v databázi Scopus

2-s2.0-105017764450