The Mezmaiskaya cave is important as far as Neanderthals are concerned, and their replacement by modern humans – see https://arstechnica.com/science/2018/03/five-new-ancient-genomes-tell-us… … five new genomes tell us about Neanderthal tribes. The Mezmaiskaya cave offered shelter to Neanderthals for thousands of years. The cave is located near Russia's border with Georgia in the Caucasus. No evidence of mixing with modern humans was found. The two groups are separated by a catstrophic layer of ash. At https://en.wikipedia.org/wiki/Mezmaiskaya_cave … seven layers of Neanderthal occupation were found dating from 70,000 to 40,000 years ago.
At www.peabody.harvard.edu/files/Otte-1.pdf … Marcel Otte, 'Comments on Mezmaiskaya' concerns the successors to the Neanderthals, the Upper Palaeolithic Aurignacians. These people are also known from the Zagros mountains zone in Iraq, the Balkans and Crimea, among other places.
At www.academia.edu/21708535/Mezmaiskaya_Cave_A_Neanderthal_Occupation_in_t… … which was published by Current Anthropology (1999). The cave contains a stratified sequence of Middle and Late Palaeolithic levels.
At www.pnas.org/content/pnas/108/21/8611.full.pdf … which concerns advances in radiocarbon dating of Neanderthal and Aurignacian remains at the Mezmaiskaya cave. The findings confirm a lack of reliably dated Neanderthal fossils younger than 40,000 years ago – in any region of northern Eurasia (including the Caucasus).