Volcanic ash dating
Recent research has shown that nonvisible ash layers (Fig.1) can also be detected in marine and terrestrial sequences (19).The CI occurs early in this dry phase, which dates it to the lower part of HE4.() Schematic representation of the position of the CI with respect to the MP to UP transition in six of the archaeological sequences investigated within the Response of Humans to Abrupt Environmental Transitions Project.In core LC21, peaks in concentrations of magnetic susceptibility, Rb, and K correspond to peak CI tephra influx, whereas the longer-lasting high values for Ti and Fe reflect higher atmospheric dust influx.The marked reduction in tree pollen percentages in the Tenaghi Philippon sequence is also considered to reflect adversely dry conditions.The latter experienced marked population decline from 40 ka B. Over time, they also developed more advanced stone tool kits, created increasingly sophisticated ornamental and ritual objects, and formed closer social networks, both heralding and signaling the transition from Middle to Upper Paleolithic cultures (4).
Robust tests of proposed causal links between climate change, environmental response, and cultural adaptations during the Middle and Upper Paleolithic, therefore, require more secure dating and correlation of archaeological and geologic records.Consisting mainly of tiny glass particles (commonly Scanning electron photomicrograph of distal cryptotephra shards associated with the visible Campanian Ignimbrite layer in the Tenaghi Philippon sequence.(Photo by Suzanne Mac Lachlan, British Ocean Sediment Core Research Facility, National Oceanography Centre, Southampton.) ) four important central European archaeological cave sequences: Klissoura, Golema Pesht, Kozarnika, and Tabula Traiana (Fig. To confirm its role as a valid, precise correlation marker, we also generated a robust dataset of the proximal chemical composition of the CI (21), against which the chemical signatures of distal CI layers have been compared (Fig. The results provide a secure common isochronous marker, which directly ties marine and terrestrial paleoenvironmental records with archaeological sequences over an expanded region that includes sites from both south and north of the Mediterranean.By synchronizing the paleoclimatic and archaeological records using the CI, we find results that contradict prevailing hypotheses about the effects of volcanic activity and climate on Neanderthals and AMHs (11, 12).) Position of the CI (black, visible glass shards; gray, cryptotephra) with respect to proxy evidence for a period of dry conditions in the eastern Mediterranean considered to approximate HE4.