New discoveries of the Vedde Ash in southern Sweden and Scotland

The Vedde Ash (c 10 300 C-14 BP) provides a key rime-parallel marker horizo n within the Younger Dryas chronozone or GS-1 event of the GRIP stratigraph y. Until recently, the known distribution of wind-blown Vedde Ash outside I celand was restricted to the west coast of Norway, off-shore sequences clos e to the Outer Hebrides and the Greenland summit GRIP ice core. The first d iscoveries of the Vedde Ash in Scotland were reported in 1997, following th e development of a new technique for extracting rtlyolitic micro-tephra par ticles from minerogenic deposits. Here we report on the discovery of the Ve dde Ash at additional sites in Scotland and at sites in southern Sweden. Th e concentration of tephra particles in sediments is highest in sites in wes tern Norway, but is also relatively high in sites in southwestern Sweden. s uggesting that the main ash cloud travelled eastwards from its volcanic sou rce of Katla. in southern Iceland. Electron microprobe analyses do not indi cate any clear geochemical evolution within the samples reported here.