Littorina Sea (also Litorina Sea) is a geological

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

stage of the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and fr ...

, which existed around 7500–4000 BP and followed the

Mastogloia Sea The Mastogloia Sea is one of the prehistoric stages of the Baltic Sea in its development after the last ice age. This took place 8000 years ago following the Ancylus Lake stage and preceding the Littorina Sea stage. Overview Towards its demise, ...

, a transitional stage of the

Ancylus Lake Ancylus Lake is a name given by geologists to a large freshwater lake that existed in northern Europe approximately from 9500 to 8000 years B.C being in effect one of various predecessors to the modern Baltic Sea. Origin, evolution and demise The ...

. This stage and form of the body of water is named after

common periwinkle The common periwinkle or winkle (''Littorina littorea'') is a species of small edible whelk or sea snail, a marine gastropod mollusc that has gills and an operculum, and is classified within the family Littorinidae, the periwinkles.Reid, Dav ...

(''Littorina littorea''), then a prevailing mollusc in the waters, which indicates its salinity. A

transgression Transgression may refer to: Legal, religious and social *Sin, a violation of God's Ten Commandments or other elements of God's moral law *Crime, legal transgression, usually created by a violation of social or economic boundary **In civil law ju ...

of the Baltic approximately 4500 BP widened its ocean link, allowing it to reach a peak of salinity during the warmer

Atlantic period The Atlantic in palaeoclimatology was the warmest and moistest Blytt–Sernander period, pollen zone and chronozone of Holocene northern Europe. The climate was generally warmer than today. It was preceded by the Boreal (period), Boreal, with a c ...

of European climatology. At this peak, the sea bore twice the volume of water and covered 26.5% more land than it does today. As the period ended, the features of the modern coast appeared, including lagoons, spits, and dunes. Notable exceptions include steep terraces such as the

Øresund Øresund or Öresund (, ; da, Øresund ; sv, Öresund ), commonly known in English as the Sound, is a strait which forms the Danish–Swedish border, separating Zealand (Denmark) from Scania (Sweden). The strait has a length of ; its width ...

where the recession of sea level exposes less dry land. During the period,

temperate deciduous forest Temperate deciduous or temperate broad-leaf forests are a variety of temperate forest 'dominated' by trees that lose their leaves each year. They are found in areas with warm moist summers and cool winters. The six major areas of this forest typ ...

crept north to cover the littoral hinterland.

Bibliography

* {{Pleistocene Lakes and Seas History of the Baltic Sea Holocene 7th millennium BC 6th millennium BC 5th millennium BC 8th millennium BC