Sudden rise in sea level (Meltwater pulse 1C) by 6.5 m (21 ft) in less than 140 years; this concludes the early Holocene sea level rise and sea level remains largely stable throughout the Neolithic. (jan 1, 6200 BC – jan 1, 5600 BC)
Description:
https://en.wikipedia.org/wiki/Early_Holocene_sea_level_riseAdded to timeline:
Date:
jan 1, 6200 BC
jan 1, 5600 BC
~ 600 years