Petrography and provenance of floor sediments from the Loutra Almopias Cave (Pella, Macedonia, Greece)

• Main Authors: Georgiadis, Ioannis, Chatzopoulou, Katerina, Kantiranis, Nikolaos, Ioakeimidis, Ioakeim, Tsirambides, Ananias
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Digital Commons @ University of South Florida 2019
• Subjects: channel and slackwater facies; fluvial; kutnohorite; mountain hare; Loutra Almopias Cave; Greece; Paleontology; Sedimentology; Speleology; Lepus timidus
• Online Access: https://digitalcommons.usf.edu/ijs/vol48/iss3/2; https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2271&context=ijs

Thirty seven floor sediment samples of Upper Pleistocene age from the Loutra Almopias Cave were collected from different beds and stratigraphic columns on the basis of their induration grade, grain distribution, and paleontological findings. Channel facies make up the bulk of the clastic sediments found in the cave passages. Slackwater facies compose the final layer of all the stratigraphic sections of the examined cave. The floor sediments are mineralogically immature, since they contain many ferromagnesian minerals, feldspars (especially plagioclase) and quartz. The extensive presence of silicate minerals means that the phyllites, gneisses, schists, ophiolitic rocks and the clastic Mariam Formation of the Almopia Zone are the main detrital load source, along with the flysch of the neighboring Pelagonian Zone. The presence of sand-sized grains, pebbles and cobbles of dolomitic or calcitic composition also designates the carbonate rocks of the Almopia and Pelagonian Zones as primary sources. The dolomite and calcite content of secondary chemical origin in the cave sediments is very limited. Kutnohorite, isomorphous with dolomite, was found for first time in a Greek cave. The provenance of the sediments is mixed; they are composed mainly of the weathering materials of the Alpine metamorphic basement and the carbonate rocks outcropping adjacent to the cave. The sediments were transported and deposited inside the cave, after rapid weathering and erosion of the surrounding rocks, under a tectonically active regime. The mineralogical variation in the stratigraphic columns demonstrates variations in the clastic load, due to the different weathering intensity periods. Most of the sediments are fluvial deposits, and one is considered a glacial deposit. Fossils of Lepus timidus (mountain hare) found within the cave represent the southernmost record of this species in Europe. Its presence signifies a cool phase at the end of the last glacial period before the onset of the warm Holocene Epoch.