Glacial Stratigraphy of the Upper Mersey Valley,Tasmania

The upper Mersey Valley was glaciated on three occasions during the Pleistocene. The youngest, Rowallan Claciation, probably commenced after 28000 years B.P. The maximum ice limit was attained before 13500 years B.P., and retreat occurred before 10000years B.P. Deposits associated with Rowallan Glaciation are weakly weathered chemically. They overlie moderately weathered deposits that were formed during the Arm Glaciation, which is inferred from relative dating data to have occurred before the Last Interglacial Stage. North of the deposits and ice limits of the Arm Glaciation extremely weathered tills and rhythmites occur. They were formed by ice of the Croesus Glaciation which is inferred to be of Early Pleistocene age or older.