Evolution of Mg/Ca and Sr/Ca ratios during the experimental dissolution of limestone

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F19%3A73598584" target="_blank" >RIV/61989592:15310/19:73598584 - isvavai.cz</a>

Alternative codes found

RIV/00216224:14310/19:00109975

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0009254119302840" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0009254119302840</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.chemgeo.2019.05.040" target="_blank" >10.1016/j.chemgeo.2019.05.040</a>

Result language

angličtina

Original language name

Evolution of Mg/Ca and Sr/Ca ratios during the experimental dissolution of limestone

Original language description

Magnesium (Mg) and strontium (Sr) preserved in speleothems are among the terrestrial climatic proxies. The mechanism of their release from impurities in limestone bedrock is usually neglected in paleoclimatic studies mainly because it is not very well understood; most cation release studies focus on pure minerals instead of limestone. Therefore, the Mg and Sr released from six types of limestone from the Moravian Karst (Czech Republic) were studied experimentally and compared with the dripwater data coming from the Punkva Caves (Moravian Karst) formed in two of the studied limestone types. The dissolution data were used to calibrate a kinetic dissolution model. The results show an incongruent dissolution of Mg-calcite and dolomite, pronounced especially in advanced stages of the dissolution. According to the results, the trace element ratios in solution were dependent mainly on (1) the limestone composition (i.e., the Mg-calcite and dolomite availability and the stoichiometry of individual minerals) and (2) on the extent of limestone-solution interaction (controlled by dissolution dynamics). Modeling indicated that the dynamics depend on the ratios of the area of rock–water and air–water interfaces to the water volume. Moreover, modeling suggests that the dynamics and subsequently also the trace element ratios are influenced by (a) the fresh surface dissolution during the initial stages of interaction and by (b) the preferential release of trace elements from mineral surfaces (nonstoichiometric dissolution). The effects of disturbed surfaces and preferential leaching are limited by available fresh surfaces. Fresh surfaces are formed through rock crushing, e.g., during physical weathering (in the field) or sample preparation (in a laboratory). The dripwaters from Punkva Caves had trace element ratios with values between the ratios resulting from the experimental dissolution of the limestones present on the site, indicating a naturally mixed composition of waters. This study has shown that Mg/Ca and Sr/Ca ratios in dripwaters might be controlled by various climate-independent variables, which raises further questions about utilizing the ratios as paleoclimatic proxies.

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

10504 - Mineralogy

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

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

Name of the periodical

CHEMICAL GEOLOGY

ISSN

0009-2541

e-ISSN

—

Volume of the periodical

523

Issue of the periodical within the volume

SEP

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

14

Pages from-to

107-120

UT code for WoS article

000480333200010

EID of the result in the Scopus database

2-s2.0-85067694248