An event stratigraphy for the Last Glacial–Holocene transition in eastern middle Sweden: results from investigations of varved clay and terrestrial sequences

This paper presents an event stratigraphy for the Last Glacial–Holocene transition in eastern middle Sweden. The event stratigraphy for eastern middle Sweden comprises ten events and covers the time-span from ca 12,900 to 10,200 cal yr BP. The local event stratigraphy has been linked to the GRIP isotopic event stratigraphy by different correlations. The onset of the Younger Dryas is dated to 12,650 cal yr BP. This cold event lasted for ca 1125 cal yr in the area. The Vedde Ash (ca 12,000 cal yr BP) has been recorded in two terrestrial sequences, which makes it possible to exactly link the event stratigraphy to the GRIP ice-core and to marine cores in the North Atlantic region. The final drainage of the Baltic Ice Lake has been dated to ca 11,560 cal yr BP, which predates the Younger Dryas/Preboreal climatic boundary with ca 35 yr. An early Holocene cold event has been detected both in terrestrial and varved clay sequences at ca 11,305–11,185 cal yr BP. This cold event coincides almost exactly with a brackish water phase in the Baltic Sea. A previously unrecorded early Holocene tephra horizon has been found in lacustrine sediments at ca 10,200 cal yr BP.