Site formation processes in Theopetra Cave: A record of climatic change during the late pleistocene and early Holocene in site formation processes inTheopetra Cave

Theopetra Cave preserves a 6.4-m-thick sedimentary sequence characterized b y alternating, mostly water-lain sediments, and multisequence burnt layers. Eighteen principal radiocarbon ages provide temporal control for this sequ ence. The sediments of the cave were examined using micromorphological tech niques, which involves the study of petrographic thin sections produced fro m resin-impregnated, undisturbed blocks of sediment. Several distinct cold periods are recorded in the sediments. The earliest of these represents a m ajor cooling, and it is tentatively assigned to Oxygen Isotope Stage 4 on t he basis of the sedimentation rate and the associated sequence of events. A brief cold event affected the uppermost part of a burnt layer dated to ca. 46 kyr B.P., but its effect ended well before 40 kyr B.P. The second major cold phase spans the period between around 33 kyr B.P. and the end of Last Glacial Maximum (16 kyr B,P.). However, there is ample evidence for a mild er interval around 25 kyr B.P. It is argued that a distinctive, albeit weak er and brief cold peak, at about 11 kyr B.P., provides the strongest eviden ce so fax obtained in Greece for the Younger Dryas event. Both major cold p hases are characterized by a sequence of events that started with alternati ng freeze-thaw activity and phosphate cementation and ended with erosion. T he return to milder conditions is accompanied by natural aggradation inside the cave. The aggradation accelerated throughout much of the glacial phase and ended soon after the Last Glacial Maximum. In addition, two other majo r erosional events are recorded in the cave. The first may be correlated wi th an early Holocene arid interval at around 7.5 kyr B.P. The second is ten tatively assigned to the end of Neolithic, although it is not clear if it w as triggered by a climatic change or by human disturbance of the landscape. The general sedimentation pattern at Theopetra is comparable with the tren d of the alluviation history in the Plain of Thessaly. Moreover, the observ ed correlation with major climatic variations, such as the Heinrich events in the Northern Atlantic, could represent the influence of northern latitud e climatic forcing on the late Pleistocene climate in central Greece. (C) 2 001 John Wiley & Sons, Inc.