THE DEPOSITIONAL HISTORY OF THE YOUNGER-DRYAS - PREBOREAL BUDI MORAINES IN SOUTH-CENTRAL ICELAND

Detailed sedimentological analysis of the Budi morainal complex in sou th-central Iceland records a rapid accumulation within marine-, coasta l, and glacial environments during a recessional phase of the glaciers within the Preboreal chronozone. Three principal outcrop areas are ch aracterized by stratified diamictite, fine-grained silty-sandstone, an d diamictite with dropstones; gravel-and sandfills of channels are als o important. Elsewhere, the morainal complex is characterized by delta ic sedimentary structures that reflect an interweaving of marine and t errestrial processes. The Budi morainal complex indicates a recession of the glacier margin, possibly since the Younger Dryas stadial. Sea-l evel changes, jokulhlaups, and glacier dynamics were responsible for f luctuation of the glacier margin and for the differential rate of calv ing during the accumulation of the morainal complex. Earlier conclusio ns on two separated glacier readvances are disputed.