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A speleogenetic history of Novoafonskaya Cave in the Western Caucasusстатья
- Авторы: Chervyatsova Olga, Potapov Sergey, Baker Jonathan, Gavryushkin Dmitry, Polyak Victor, Heizler Matt, Tokarev Sergey, Sadykov Sergey, Dbar Roman, Dublyansky Yuri
- Журнал: International Journal of Speleology
- Том: 53
- Номер: 2
- Год издания: 2024
- Издательство: Societa Speleologica Italiana
- Местоположение издательства: Italy
- Первая страница: 89
- Последняя страница: 110
- DOI: 10.5038/1827-806x.53.2.2499
- Аннотация: Speleogenesis in hypogene karst settings may be closely tied to regional tectonic dynamicsand concomitant hydrochemical evolution of karst waters. However, placing temporalconstraints on these processes can require a wider array of field observations andtechniques than for typical karst systems. Herein, we present a comprehensive study ofNovoafonskaya Cave (Western Caucasus, Abkhazia). The updated speleogenetic history ofthe cave comprises four stages: (1) the most ancient, a low-T hydrothermal (ca. 40–50°C)priming stage; (2) the main stage enabled by mixing of upwelling thermomineral and locallyrecharged common karst waters; (3) the late sulfuric-acid speleogenesis (SAS) stage, whichleft significant mineralogical overprint (gypsum and a suite of minerals resulting from thealteration of silicate sediments) but did not alter the morphology of the cave appreciably; and(4) the contemporary stage, occurring predominantly in the phreatic and epiphreatic zones.Ages of speleogenetic stages were constrained by radiometric dating (230Th-U and 40Ar/39Ar)and paleomagnetic data, alongside the Quaternary geological history of the region andpaleodynamics of the Black Sea level. Conditions for the low-T hydrothermal karstificationoccurred from Miocene – Middle Pliocene. The main stage, which created the main volumesof the cave, took place from Late Pliocene – Middle Pleistocene. The cave emerged from thephreatic into the vadose zone after ca. 400 ka ago, due to the combined effect of the BlackSea regression and intensification of tectonic uplift in the Caucasus. The presence of sulfidicwaters during dewatering led to the development of transient SAS processes during Middleto Late Pleistocene. Dating of calcite underlying SAS-associated overgrowths constrainsthe cessation of this SAS activity to within the last 147 ka. In its present state, the cavehas no connection with thermomineral waters; however, such waters are found deeper inthe southern parts of the karst massif (based on the hydrochemistry of Psyrtskha spring),implying that hypogene karstification, primarily driven by mixing corrosion, may still be activedeep in the phreatic zone.
- Добавил в систему: Гаврюшкин Дмитрий Александрович