Khvalynian transgression of the Caspian Sea was not a result of water overflow from the Siberian Proglacial lakes, nor a prototype of the Noachian flood

摘要

The paper presents a critical review of the hypothesis that the Khvalynian transgression resulted from abundant inflow of meltwater from Siberian proglacial lakes through the Aral Sea and along the Uzboi channel into the Caspian Sea, had a catastrophic character, and could be considered as a prototype of the biblical Noachian flood. A thorough analysis of evidence cited by the proponent of the hypothesis revealed the lack of factual substantiation: (1) there are no data indicative of Aral drainage; (2) there is no evidence that Siberian proglacial water was inflowing into the Caspian Sea; (3) taxonomic and spatial distribution of molluscs in Khvalynian sediments do not indicate that transgression was essentially influenced by thawing of ice sheets on the Russian Plain; (4) there is no evidence that the Khvalynian transgression was catastrophic (sea level rose by few centimeters per year over several thousands of years); (5) there are no data indicating that Khvalynian water overflowing through the Manych spillway into the Neoeuxinian lake was significant. Inflow could increase the level and salinity of the lake by 30 m and 5%o, respectively. Thus, there is no evidence that the Khvalynain transgression could serve as a reliable source for the biblical Noachian flood.