The Flandrian interglacial or stage is the name given by geologists and archaeologists in the British Isles to the first, and so far only, stage of the Holocene epoch (the present geological period), covering the period from around 12,000 years ago, at the end of the last glacial period to the present day. As such, it is in practice identical in span to the Holocene. Present climatological theory (based on analysis of Milankovitch cycles) forecasts that the present Flandrian climate should decline in temperature towards a global climate similar to that of the ice age. The current global warming phenomenon could have the effect of postponing this downturn.
The Flandrian began as the relatively short-lived Younger Dryas climate downturn came to an end. This formed the last gasp of the Devensian glaciation, the final stage of the Pleistocene epoch and is traditionally seen as the latest warm interglacial in a series that has been occurring throughout the Quaternary geological period.
The first part of the Flandrian, known as the Younger Atlantic, was a period of fairly rapid sea level rise, known as the "Flandrian Transgression" and associated with the melting of the Fenno-Scandian, Scottish, Laurentide and Cordilleran glaciers.
Fjords were formed during the Flandrian Transgression when U shaped glaciated valleys were inundated with water.