Stone-Age megastructure under the Baltic: the “Blinkerwall”
Sonar revealed a 971 m wall of about 1,670 stones at 21 m depth. It is interpreted as a hunting drive built about 10,000 years ago, before the sea rose.
Why it matters: It is one of the oldest human-made structures in Europe, now under water. It shows how rising seas hide Ice Age sites.
Kelly Graf, Ted Goebel and colleagues report on Shég’ Xdaltth’í’ (formerly McDonald Creek), 55 km south-southeast of Fairbanks. It has three Late Pleistocene occupation layers dated to about 13,800, 13,000 and 12,700 years ago. The oldest layer holds more than 80,000 specimens, including a distinctive hafted biface, bone and antler tools, animal remains and well-preserved activity areas.
Enrico Crema and colleagues used statistical models of radiocarbon and site data to track Jomon forager populations around the Kikai-Akahoya eruption about 7,300 years ago, one of the largest of the Holocene (VEI 7). They find a major population collapse in regions next to the volcano, but some nearby populations grew after the disaster, and some distant communities were hit by environmental effects that had been overlooked.
Kathleen Springer, Jeffrey Pigati, Jessica Tierney and colleagues expanded the excavations at White Sands and found 20 stratigraphic layers with human footprints in place, alongside megafauna trackways and drag lines made by travois. New radiocarbon dates on conifer pollen, combined with dates on aquatic seeds, put the footprint sequence between 23,500 and 21,700 years ago. Pollen, biomarker and sediment data record the lake turning into a playa during a dry spell that matches Dansgaard-Oeschger event 2, about 23,200 years ago.