Research in the mountains of southern Jordan resulted in the discovery
of 109 archaeological sites that are from the Lower Paleolithic to th
e Chalcolithic period [150 to 6 thousand years ago (ka)]. Beginning wi
th the Middle Paleolithic (70 ka) two site types (long-term and epheme
ral camps) are recognized. Long-term sites have larger areas, thicker
deposits, higher artifact densities, and more abundant archaeological
features than ephemeral sites. Their natural settings (elevation and e
xposure) and associated seasonal evidence (phytolith and cementum incr
ement data) indicate that long-term sites were occupied during the win
ter, wet season and ephemeral sites during the warm, dry season. These
differences in site use and seasonality likely reflect an adaptive st
rategy of transhumance that persisted to modern Bedouin times. At the
end of the Pleistocene, the onset of warmer, drier conditions induced
a shift of the long-term winter camps from relatively low (800 to 1000
meters above sea level) to high (1000 to 1250 meters above sea level)
elevations and largely reversed the earlier transhumant pattern.