ABSTRACT In this study, we present a composite δ 18 O and δ 13 C record obtained from four speleothems from the Grotta Grande del Vento Cave, located within the Frasassi karst system, northeastern Apennines of central Italy. The ages were determined by U-series analysis, employing thermal ionization mass spectrometry (TIMS), and the composite isotopic profile covers most of the time period from ca. 95,000 yr B.P. until ca. 10,000 yr B.P., including the last part of marine isotope stage (MIS) 5, most of the last glacial (MIS 4–2), and the earliest Holocene (MIS 1), with a hiatus lasting from ca. 65,000 to ca. 55,000 yr B.P. We compared this record with other speleothem records from the Eastern Mediterranean, with caves from western Portugal, with two marine records from the Eastern Mediterranean and the Aegean Sea, and with the North Greenland Ice Core Project (NGRIP) ice-core record. The Frasassi speleothem record provides further insight for a wider regional understanding of the paleoclimate record through the discrepancies and similarities between the northeastern Apennines of central Italy and the Western, Eastern, and northeastern Mediterranean regions. The time interval between ca. 86,000 and 83,000 yr B.P. shows low δ 18 O values in the Western and Eastern Mediterranean speleothems and the marine records. This period coincides with sapropel (S3) and is associated with increased hydrological activity and warming. On the other hand, Frasassi speleothem δ 18 O data do not show a similar low trend, suggesting that increased hydrological activity either did not reach the Frasassi region and/or the region received rainfall from other sources and/or the proportion of winter-summer rainfall was different. Another interval in which different conditions prevailed in the Frasassi region is during the transition from MIS 5 to glacial MIS 4, from ca. 83,000 to 65,000 yr B.P., when Frasassi speleothem δ 18 O values decreased, whereas all other records show a clear increase in δ 18 O. Comparison with the NGRIP record suggests that Northern Hemisphere temperature changes are reflected in Frasassi speleothem δ 18 O fluctuations during this interval. A major pronounced isotopic event associated with warming and pluvial conditions during the last glacial evident in the entire Mediterranean region between ca. 54,500 and 52,500 yr B.P. is recorded also in the Frasassi speleothem isotopic profile. This event is followed by a transition from wet and warm climatic conditions to cold conditions. The end of the last glacial is associated with climate instability, evident mainly from the very large oscillations in the Frasassi δ 13 C record. The transition from the last glacial to early Holocene is characterized by a decreasing trend in δ 18 O and a sharp increase in δ 13 C values.

Poljes are distinctive features of Mediterranean karst landscapes, but their Pleistocene sedimentary fills have not been widely investigated. Most previous research has focused on their formation and hydrology. Many Mediterranean poljes are situated downstream of high mountains that were glaciated during the cold stages of the Pleistocene, so that meltwater streams delivered glacially derived sediment into these basins. This study examines the Pleistocene alluvial records in karst poljes surrounding Mount Orjen in western Montenegro and explores their wider significance. There is a record of at least four glaciations preserved on Mount Orjen—two from the Middle Pleistocene (marine isotope stages [MIS] 12 and 6) and two from the last cold stage (MIS 5d-2), including the Younger Dryas. Detailed sedimentological analysis and uranium-series dating indicate that the Orjen poljes were filled with thick deposits of coarse- and fine-grained alluvium prior to 350 ka, during the major glacial phase of MIS 12. During the cold stages that followed MIS 12, ice was less extensive and limited to the Orjen plateau, and there is little evidence of outwash deposition during these later glaciations. Surface runoff and sediment supply were greatly reduced after MIS 12 and largely channeled into the subterranean karst network. The poljes around Orjen contain some of the best-preserved records of Middle Pleistocene glacial outwash in the Mediterranean, representing an important legacy of an extensive Middle Pleistocene glaciation for which wider impacts have not been fully appreciated.