Micro-karstification in a stalagmite, Küpeli Cave, southern Turkey

Abstract

This article deals with micro-karstification forming abundant dissolution features in a stalagmite from Küpeli Cave in southern Turkey. Dissolution occurs when cave water enriched with CO2 from the atmosphere and soil seeps into the stalagmite. Water is transmitted from the surface of the stalagmite to the interior by the roughly vertical or diagonal notch-shaped pores formed by the enlargement of intercrystalline pores by dissolution. These slightly elongated pores appear embedded in different parts of the stalagmite and characterize different stages of dissolution during the stalagmite formation. Later, when this water reaches the relatively more permeable growth layer surfaces, it flows along these surfaces, and diffuse dissolution features form. These features include micro-scale pitted and etched surface structures, rounded and enlarged crystal boundaries and intercrystalline pores, and the breakdown of relatively large crystals into small crystals (micritization). When the percolating water is sufficiently saturated with calcium carbonate in the stalagmite, secondary calcite precipitation occurs as rim and pore-filling cements within the pores formed as a result of dissolution. In general, dissolution and calcite re-precipitation as cement are early diagenetic events and occur at different stages of stalagmite development due to seasonal variation in CO2 and CaCO3 contents of the water in the epikarst zone and within the stalagmite. These conditions were probably provided during the wet season.