Coastal dynamics at the top of the Unskaya Bay and its prehistoric settlement in the Holocene (the White Sea, northwestern Russia)

We present new data that were generated by intensive field surveys and comprehensive geological-geomorphological, geophysical (ground-penetrating radar (GPR) profiling), paleolimnological and geoarchaeological studies within the top of the Unskaya Bay (the Letniy Coast of the White Sea) in 2020–2023. It was supplemented by radiocarbon dating and diatom analysis of the sediment cores from Chervozero and Svetloe Lakes (Una village area, Onezhskoye Pomorye National Park, Arhangelsk region), as well as interpretation of detailed space images. As a result, we reconstructed relative sea level (RSL) changes within the southern coast of the Unskaya Bay and its initial settlement by prehistoric humans in the Holocene. It was revealed that the late glacial transgression ended at an altitude of 9.8 m a. s. l. no later than ~ 10.3 thousand cal BP, at an altitude of ~ 8.5 m a. s. l. – no later than 10.0 thousand cal BP. The relative sea level didn’t exceed ~ 8.5 m a. s. l. during the Tapes transgression. The archaeologi- cal sites were facing the shores of an ancient strait that existed between the estuaries of the Unskaya and Ukhta Bays and were located at 9–10 m a. s. l.