Physical weathering by glaciers enhances silicon mobilisation and isotopic fractionation

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F21%3A10441903" target="_blank" >RIV/00216208:11310/21:10441903 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=6bKeloNYQu" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=6bKeloNYQu</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.7185/geochemlet.2126" target="_blank" >10.7185/geochemlet.2126</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Physical weathering by glaciers enhances silicon mobilisation and isotopic fractionation

Popis výsledku v původním jazyce

Glacial meltwaters export substantial quantities of dissolved and dissolvable amorphous silicon (DSi and ASi), providing an essential nutrient for downstream diatoms. Evidence suggests that glacially exported DSi is isotopically light compared to DSi in non-glaciated rivers. However, the isotopic fractionation mechanisms are not well constrained, indicating an important gap in our understanding of processes in the global Si cycle. We use rock crushing experiments to mimic subglacial physical erosion, to provide insight into subglacial isotope fractionation. Isotopically light DSi [δ(30)SiDSi] released following initial dissolution of freshly ground mineral surfaces (down to -2.12 +/- 0.02 promile) suggests mechanochemical reactions induce isotopic fractionation, explaining the low δ(30)SiDSi composition of subglacial runoff. ASi with a consistent isotopic composition is present in all mechanically weathered samples, but concentrations are elevated in samples that have undergone more intense physical grinding. These experiments illustrate the critical role of physical processes in driving isotopic fractionation and biogeochemical weathering in subglacial environments. Understanding perturbations in high latitude Si cycling under climatic change will likely depend on the response of mechanochemical weathering to increased glacial melt.

Název v anglickém jazyce

Physical weathering by glaciers enhances silicon mobilisation and isotopic fractionation

Popis výsledku anglicky

Glacial meltwaters export substantial quantities of dissolved and dissolvable amorphous silicon (DSi and ASi), providing an essential nutrient for downstream diatoms. Evidence suggests that glacially exported DSi is isotopically light compared to DSi in non-glaciated rivers. However, the isotopic fractionation mechanisms are not well constrained, indicating an important gap in our understanding of processes in the global Si cycle. We use rock crushing experiments to mimic subglacial physical erosion, to provide insight into subglacial isotope fractionation. Isotopically light DSi [δ(30)SiDSi] released following initial dissolution of freshly ground mineral surfaces (down to -2.12 +/- 0.02 promile) suggests mechanochemical reactions induce isotopic fractionation, explaining the low δ(30)SiDSi composition of subglacial runoff. ASi with a consistent isotopic composition is present in all mechanically weathered samples, but concentrations are elevated in samples that have undergone more intense physical grinding. These experiments illustrate the critical role of physical processes in driving isotopic fractionation and biogeochemical weathering in subglacial environments. Understanding perturbations in high latitude Si cycling under climatic change will likely depend on the response of mechanochemical weathering to increased glacial melt.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

Geochemical Perspectives Letters

ISSN

2410-339X

e-ISSN

—

Svazek periodika

19

Číslo periodika v rámci svazku

October

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

6

Strana od-do

7-12

Kód UT WoS článku

000770975400002

EID výsledku v databázi Scopus

2-s2.0-85126101477