Paleohydrological history of Lake Allos (2200 m a.s.l) since 13 500 cal a <scp>bp</scp> in the Mediterranean Alps inferred from an ostracod ? ¹⁸ O record

This paper presents the first Lateglacial/Holocene (the last 13 500 cal a bp) ostracod ?18O record to infer hydroclimate variability in Southern French Alps. Cytherissa lacustris (?18Osp) shells extracted from sediments of Lake Allos allowed reconstruction ?18Olake water (?18Olw) except for interval 5800–2800 bp. The shape Younger Dryas (YD) clearly differed records documented northern First, ?18Olw values remained close modern before marked drop ca. 12 000 Then, after several oscillations, increased, reaching highest value 6100 bp during thermal optimum this latitude. Finally, low occurred 450 100 Little Ice Age (LIA) following Medieval Climate anomaly. At beginning YD, probably reflected changes local glacier dynamics and precipitation sources. decrease was associated with higher freshwater inputs second half YD. During LIA, are consistent torrential activity lower air temperatures.