A multi-proxy record of Holocene climatic change in southwestern Spain: the Laguna de

Abstract: Palaeolimiinological data (diatoms, ostracods, foraminifera, molluscs, aquatic pollen and lithologyj) from a radiocarbon dated sediment core from a saline lake, the Laguna de Medina, provide the first complete record of Holocene lake-level change for southwest Spain for the last c. 9000 cal. years. The lake has always been relatively shallow but has exhibited marked fluctuations in salinity and water depth, especially in the earlier record when oscillationis ctUlminate in maxinmuim lake levels from c. 6960-6680 cal. BP (c. 6070-5830 BP), indicating enhanced early- to mid-Holocene humidity and a mid-Holocene humidity maximuLm. Prolonged shallowing thereafter reflects in par-t increased aridity in the later Holocene. Lake desiccation followed by a c. 800-yr phase (zone 2) of major limnliological change commencing at c. 8000 cal. BP (c. 7200 BP), and a ntimber of other abrupt desiccation events, are also noteworthy. The mid-Holocene maximum is consistent with widespread evidence for high lake levels around 6000 BP, but the underlying climatic mechanisms are tincertaini; there is some evidence it may apply predomiainantly to the westerly (Atlantic) Peninsula, withi earlier maxima in the east. Phases of abrupt limnological change show affinities with African data; as in African lakes, the 'zone 2 ' phase appears to be a response to global change centred oni c. 8.1-8.2 cal. BP. Other correlations miiade are tenuous, due partly to the lack of preservation in the upper record of some of the proxies used. Other desiccation events currently appear to be of more local significance, reflecting high decadal- to century-scale climatic variability throughout the Holocene