J 2017

Evolution of Mg/Ca Ratios During Limestone Dissolution Under Epikarstic Conditions

PRACNÝ, Pavel, Jiří FAIMON, Dalibor VŠIANSKÝ a Ludvík KABELKA

Základní údaje

Originální název

Evolution of Mg/Ca Ratios During Limestone Dissolution Under Epikarstic Conditions

Autoři

PRACNÝ, Pavel (203 Česká republika, garant, domácí), Jiří FAIMON (203 Česká republika, domácí), Dalibor VŠIANSKÝ (203 Česká republika, domácí) a Ludvík KABELKA (203 Česká republika)

Vydání

Aquatic Geochemistry, New York, Springer, 2017, 1380-6165

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10505 Geology

Stát vydavatele

Nizozemské království

Utajení

není předmětem státního či obchodního tajemství

Impakt faktor

Impact factor: 1.418

Kód RIV

RIV/00216224:14310/17:00096253

Organizační jednotka

Přírodovědecká fakulta

UT WoS

000399092500004

Klíčová slova anglicky

Moravian Karst; Limestone dissolution; Kinetic model; Cave dripwater; Mg-calcite

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 3. 4. 2018 15:17, Ing. Nicole Zrilić

Anotace

V originále

The Mg/Ca ratios in karst water are generally believed to comprise information on climate and, being encoded in speleothems, they are utilized as paleoenvironmental proxy. However, the mechanism and dynamic of Mg release from limestone during dissolution is not well understood. A theoretical evolution of the Mg/Ca ratios during limestone dissolution under epikarstic conditions (T = 10 °C, logPCO2 = –1.5) was studied via a dynamic model. The results were compared with (1) the dripwater data set collected in Punkva Caves (Moravian Karst, Czech Republic) during one-year period and (2) the published data from various locations worldwide. The modeling showed that the Mg/Ca ratios are governed by composition of Mg-calcite present in limestone. Two distinct stages in the dissolution dynamics were recognized: (1) an initial congruent dissolution with stoichiometric release of Ca and Mg and, subsequently, (2) an incongruent dissolution demonstrated by the gradual release of Mg with simultaneous Ca decrease via calcite precipitation. Additional identified factors influencing the reaction path and Mg/Ca ratio evolution were the dolomitic component of limestone and the ratio of limestone/solution boundary area to water volume. Finally, the water-rock interaction time controls the resulting Mg/Ca ratio in dripwater determining how far the dissolution proceeds along the reaction path. Thus, the study results indicate that Mg/Ca ratio depends on many factors in addition to climatic variables.