Orphan Arctic Ocean metasediment clasts: Local derivation from Alpha Ridgeor pre-2.6 Ma ice rafting?

Phyllonite and metaquartzite clasts occur in early Pliocene or possibly Mio cene sediment at the base of the University of Wisconsin Arctic Ocean core F1-380. Single-crystal Ar-40/Ar-39 laser-probe ages derived from feldspars in sediment enclosing the clasts range from Middle and Late Proterozoic to Paleozoic. The clasts occur in sediment deposited 1-2 m.y. earlier than any previously reported central Arctic Ocean ice-rafted debris, and although a n ice-rafted origin may be possible, a local source such as adjacent Alpha Ridge bedrock should also be considered.