Timing and causes of North African wet phases during the last glacial period and implications for modern human migration.

ABSTRACT: We present the first speleothem-derived central North Africa rainfall record for the last glacial period. The record reveals three main wet periods at 65-61 ka, 52.5-50.5 ka and 37.5-33 ka that lead obliquity maxima and precession minima. We find additional minor wet episodes that are synchronous with Greenland interstadials. Our results demonstrate that sub-tropical hydrology is forced by both orbital cyclicity and North Atlantic moisture sources. The record shows that after the end of a Saharan wet phase around 70 ka ago, North Africa continued to intermittently receive substantially more rainfall than today, resulting in favourable environmental conditions for modern human expansion. The encounter and subsequent mixture of Neanderthals and modern humans - which, on genetic evidence, is

SUBMITTER: Hoffmann DL 

PROVIDER: S-EPMC5093410 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature