Holocene shore displacement in the surroundings of Tallinn, North Estonia

Abstract

The Tallinn area was recovered from the Weichselian ice sheet not later than 13 ;000–12 ;800 ;cal ;yr ;BP but remained for ca 1500 years under the waters of the Baltic Ice Lake (BIL). The highest parts of Tallinn emerged from the BIL after its drainage about 11 ;600 ;cal ;yr ;BP. At the beginning of the Yoldia Sea stage the present city area was submerged by sea water, except for the highest parts of Viimsi, Lasnamäe and Nõmme. At the end of the Yoldia Sea stage the Ülemiste, Pääsküla and Männiku basins isolated from the sea. During the Ancylus Lake transgression about 10 ;300 ;cal ;yr ;BP the highest coastline at 34–36 ;m ;a.s.l. broadly outlined the klint escarpment. The Litorina Sea transgressional coastline at 7800–7600 ;cal ;yr ;BP and beach formations at 21–22 ;m ;a.s.l. are less developed than the Ancylus ones and often covered by aeolian deposits. Toompea arched north as a cape in the Litorina Sea and the previous Viimsi Island joined with the mainland. During the Limnea Sea stage (4400 ;cal ;yr ;BP up to the present, the highest coastline at ca ;12 ;m ;a.s.l.) land increased mostly at the back of Kakumäe and Kopli bays. The Kakumäe Peninsula obtained its outline about 2800 years ago, the Kopli Peninsula ca 1000 years later. The Paljassaar Peninsula was the latest to be formed ca 100 years ago. The attached palaeogeographical maps display shore displacement during the different stages of the Baltic Sea in the vicinity of Tallinn.

Keywords

• Holocene
• Baltic Sea
• shore displacement
• Tallinn
• North Estonia.