Paleoclimatology of the Levant from Zalmon Cave speleothems, the northern Jordan Valley, Israel

The Levant region of Israel, located along the Eastern Mediterranean Sea, is characterized by Mediterranean climate, but sixty km eastwards towards the Dead Sea Rift Valley (DSRV), the region rapidly becomes a ‘rain shadowʼ desert. Speleothems from the Mediterranean climate zone continuously grew throughout several glacial/interglacial cycles, indicating that water was always available in the unsaturated zone. Their δ¹⁸O variations match global and regional climate changes, with the Eastern Mediterranean Sea being the major control on their δ¹⁸O values, as evident from the similarity between the speleothems and the planktonic foraminifer G. ruber records. In contrast, speleothems along the central and southern segments of the DSRV grew mainly during last glacial periods coinciding with the higher stands of Lake Lisan, the precursor of the present-day Dead Sea. This paper discusses the newly discovered Zalmon Cave speleothems, located in the northern segment of the DSRV shedding light on the hydrological conditions along the rift during last glacial. Unlike speleothems located further south along the DSRV, Zalmon Cave speleothems grew both during glacial and interglacial periods. However, during last glacial their δ¹⁸O values, shifted to lower values by ∼1–2‰ relative to speleothems from central Israel coinciding also with the largest difference in δ¹⁸O values between Zalmon Cave speleothems and the marine record. The data suggest that a change of the westerlies' storm tracks occurred during most of the last glacial period, which resulted in increased rainfall in the northern DSRV providing freshwater input during the otherwise relatively ‘drierʼ glacial.