HANSON, Todd D., and STRASSER, J.C., Geology Dept., Augustana College, 639 – 38 Street, Rock Island, IL 61201; GOSSE, J. C., Dept. of Geology, University of Kansas, Lawrence, KS 66045

A large ridge, interpreted by Williams and Ferrians (1961) as a <1000 yr. old recessional moraine, was studied in an effort to test their interpretation. Alternatively, the ridge may be an erosional remnant of an older landform, such as a former glacier bed or kame terrace. The feature studied is located approximately one km west of the Matanuska Glacier terminus, and it trends 340º. Undercutting by a river has created exposures on the southwest side of the ridge, on the opposite side from the modern glacial margin. The ridge is composed dominantly of massive, matrix-supported diamicton, with a greater concentration of clasts towards the top. Clasts are mainly angular to subangular metasediments, reflecting probable supraglacial transport. Approximately 10% of the clasts were rounded to subrounded metavolcanics and plutonics, suggesting a minor subglacial or basal component to the clasts as well. Clast fabric analyses at one site shows a lack of preferred orientation, while at two other sites a moderate fabric is evident (S1=0.65 and 0.52), with clasts trending approximately perpendicular to the ridge crest. These results are consistent with Lawson's (1979) studies of modern glacial deposits, suggesting a probable origin from sediment gravity flows from the former glacier terminus, although the lack of both hummocky morphology and distinct internal layering suggests limited reworking of sediments by subsequent flow processes.