Chronology of Late Holocene Glacier Recessions in the Cascade Range and Deposition of a Recent Esker in a Cirque Basin, North Cascade Range, Washington
Recessional events over the past 800 years between 23 glaciers of varying size, elevation and aspect in the North Cascades and on Mount Rainier were found to be broadly synchronous. Eight periods of recession were identified (early 1200s, the mid-1300s, the mid to late-1400s, between 1520 and 1580, the mid to late-1600s, between 1740 and 1780, between 1820 and 1860, and between 1880 and 1920), although the three earliest periods are poorly documented. Establishment of a more detailed chronology is dependent upon more accurate and consistent dating methods and the acquisition of more data. This study focuses on late Holocene fluctuations of valley glaciers and glacial landform evolution. This thesis establishes a moraine chronology of the beginning of recessional episodes over the last 800 years. The spatial and temporal scales of the recessional events are also discussed. This thesis also focuses on the problem of esker genesis in a cirque basin near Mount Redoubt. It attempts to determine why this esker is located in a somewhat unusual setting and what processes controlled its deposition and form.