EPMA analysis of a stalagmite from Küpeli Cave, southern Turkey: implications on detrital sediments

Abstract

In this study, the chemical composition of calcite crystals and pore-filling sediments in a stalagmite from Küpeli Cave was investigated for the first time using the electron probe microanalysis (EPMA). It was supplemented by petrographic, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) analyses to improve understanding of EPMA findings. The EPMA results show that the stalagmite consists mainly of pure calcite crystals with a CaO composition of 56 ± 1 wt%. These crystals are the primary components of both sparite calcite mosaic and dendritic microfabrics. Calcite crystals in the dendritic microfabric appear as long fiber-like crystals surrounding calcite needles extending in two directions and cement filling the pores between these crystals. Internal sediments are also abundant in the pores of the dendritic microfabric and contain components such as Al₂O₃, SiO₂, K₂O, FeO, and CaO. The XRD analyses show that the pore-filling sediments consist mainly of calcite, smectite, quartz, chlorite, and feldspar. The abundance of siliceous constituents in the internal sediment, together with the stalagmite position within the conduit, indicate that the clastic sediments in the pores were deposited primarily by floods. However, it is thought that some clastic carbonates in the pores may have been transported by water dripping from the epikarst region.