2017
Evolution of Mg/Ca Ratios During Limestone Dissolution Under Epikarstic Conditions
PRACNÝ, Pavel, Jiří FAIMON, Dalibor VŠIANSKÝ a Ludvík KABELKAZákladní 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
Odkazy
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
Štítky
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.