Geological Society of Greece 52 Volume 57 Research Paper PALEOHYDROLOGY OF THE STEFANINA CAVE (GREECE) Lazaridis Georgios* 1 , Kyriaki Fellachidou 1 , Maria-Nefeli Georgaki 1 1 Aristotle University of Thessaloniki, Department of Geology, Laboratory of Geology and Palaeontology, 54124 Thessaloniki, Greece *geolaz@geo.auth.gr, fellachid@gmail.com nefgeor@gmail.com Abstract The development of hypergene Stefanina Cave, the hydrological conditions, and the maximum discharge of the paleo-flow are studied, based on its pattern in ground-plan, the geometry of the passage, and the peak flow velocity from the dimensions of the scallops. The village of Stefanina is located East of Thessaloniki and the cave NE of the village. A study was conducted measuring the orientation of the discontinuities of the rocks inside and outside the cave, the scallops in various sites to estimate the flow velocities, and in addition, were taken photographs for the full analysis of its cross- section. The cave-in ground-plan has a pattern of branches, which is often associated with recharging through karstic depressions. The shape of the passages is both curvilinear and angular, depending on the foliage and the fractures. The symmetrical phreatic passage shape has been evolved to a vadose canyon, forming a keyhole passage in cross-section. This is indicative of a water table drop. The scallops are visible in a meandering channel, where the discharge of the paleo-flow is estimated. The estimated peak flow velocity ranges from 0.4 to 2.7 m / s, while the area-specific peak flow discharge is estimated to be 2.2 m 3 /s. On the one hand, the scallops represent the peak flow velocity, on the other hand, the karst springs have a limited maximum discharge, regardless of the size of the catchment, making it impossible to use the calculated paleo-discharge to estimate the respective catchment area. Keywords: paleohydrology, hydrological conditions, paleo-discharge, scallops, cave Περίληψη Στη μελέτη αυτή χαρτογραφείται και καταγράφεται αναλυτικά η μορφολογία και ο τρόπος ανάπτυξης του σπηλαίου των Στεφανινών, στο ομώνυμο χωριό της Μακεδονίας. Με βάση τη μορφολογία του προτύπου του σε κάτοψη είναι μέρος ενός δενδριτικού σπηλαιώδους Correspondence to: Lazaridis Georgios geolaz@geo.auth.gr DOI number: http://dx.doi.org/10.12681/ bgsg.26168 Keywords: Paleohydrology, Hydrological Conditions, Paleo-Discharge, Scallops, Cave Citation: Lazaridis, G., Fellachidou, K. and Georgaki, M.N. (2021), Paleohydrology of the Stefanina Cave (Greece). Bulletin Geological Society of Greece, 57, 52-67. Publication History: Received: 18/02/2021 Accepted: 29/06/2021 Accepted article online: 08/07/2021 The Editor wishes to thank Didier Cailhol for his work with the scientific reviewing of the manuscript and Ms Emmanouela Konstantakopoulou for editorial assistance. ©2021. The Authors This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited BGSG