Cirque forms and alpine glaciation during the Pleistocene, west-central Yukon
Description
Uplands in west-central Yukon supported alpine ice centres during the pre-Reid glaciations (Early Pleistocene). Subdued cirque forms are thought to be glacial cirques that have undergone degradation by nivation. The paleo-equilibrium line altitude (ELA) dropped as low as 1054 ± 96 m in the Crag Mountain upland (CMU). A pre-Reid age for the CMU cirques is based upon the presence of an Early-Middle Pleistocene paleosol in a moraine feature. Cirques in the Ogilvie Mountains provide proxy ELAs for the Reid (mean 1391 ± 132 m) and McConnell (mean 1488 ± 103 m) glaciations. Cirque glaciers did not form in CMU and most of Dawson Range during these later
glaciations due to a decrease in precipitation. It is suggested that the progressive marginality of cirque glaciation through the Middle and Late Pleistocene may be related to the progressive enlargement of precipitation-diverting continental ice sheets east of the Cordillera.
Resources
| Name |
Format |
Description |
Link |
| Yukon Geological Survey publication metadata |
HTML |
|
https://data.geology.gov.yk.ca/Reference/42813 |
| Original metadata (https://open.yukon.ca) |
HTML |
|
https://open.yukon.ca/information/2030f0e4-1040-4021-98de-fc9b058f15e1 |
| Report |
PDF |
|
https://ygsftp.gov.yk.ca/publications/yeg/yeg02/14_nelson.pdf |