Physical and Chemical Properties of Volcanic Glass Shards from Pozzuolana Ash, Thera Island, and from Upper and Lower Ash Layers in Eastern Mediterranean Deep Sea Sediments

Two volcanic ash layers have been correlated in deep sea piston cores from the eastern Mediterranean 1,2 . The lower ash layer ( n = 1.521) occurs between late Würm carbonate sediment and originated in an eruption more than 25,000 years ago. The upper ash layer ( n = 1.509) occurs in postglacial carbonate sediment less than 5,000 yr old. Patterns of distribution indicate that both beds of volcanic ash originated in eruptions of Santorini (Aegean Sea).