Description |
Holocene and late Pleistocene deposits in the cirques and at the mouths of Little Cottonwood and Bells Canyons are reexamined. Stratigraphy, radiocarbon dating, lichenometry, and relative age dating methods provide evidence for a new age interpretation of glacier and rock glacier deposits. Of the relative age dating methods, boulder-surface microrelief is particularly useful. Moraines and rock glaciers in the cirques are reinterpreted as being generally older than they were thought to be by previous workers. Most deposits mapped earlier as late Neoglacial are mapped here as early Neoglacial in age. Many deposits formerly thought to be early Neoglacial are considered to be of pre-Neoglacial age in this report. A Holocene pollen diagram from Albion Basin Bog is presented. The youngest moraines at the mouth of Little Cottonwood Canyon and correlative moraines at the mouth of Bells Canyon, interpreted by some workers as early Wisconsin deposits, are shown to be late Wisconsin in age (between 20,000 and 27,000 B.P.). This glaciation was correlative with the late Wisconsin rise of Lake Bonneville that overflowed at Red Rock Pass, Idaho, into the Snake River drainage. Stratigraphic relationships near the mouth of Bells Canyon provide evidence for an earlier, perhaps Illinoisan, glaciation that was also correlative with a high stage of Lake Bonneville. |