The Wisconsinan deglaciation, of southern Saskatchewan and adjacent areas

1979 ◽  
Vol 16 (4) ◽  
pp. 913-938 ◽  
Author(s):  
E. A. Christiansen

The Wisconsinan deglaciation of southern Saskatchewan and adjacent areas of Alberta, Manitoba, Montana, and North Dakota is depicted in nine phases of glacial advance, readvance, and retreat. Althouth there is some uncertainty whether Phase 1 or 2 represents the Classical Wisconsin (Woodfordian) terminus, the glacial history from about 17 000–10 000 years ago is considered.Although the glacier margin retreated at an increasing rate in Saskatchewan, the volume of meltwater released by the melting glacier decreased with time. The large meltwater channels south of the Cypress Hills as compared to those to the north and the fact that most of the glacial lake deposits north of the Cypress Hills came from extraglacial rivers suggest there was much more glacial meltwater activity south of the Cypress Hills than north of them. This in turn suggests that much of the ice melted before significant retreat of the ice front took place.

2021 ◽  
pp. 1-16
Author(s):  
Scott A. Reynhout ◽  
Michael R. Kaplan ◽  
Esteban A. Sagredo ◽  
Juan Carlos Aravena ◽  
Rodrigo L. Soteres ◽  
...  

Abstract In the Cordillera Darwin, southernmost South America, we used 10Be and 14C dating, dendrochronology, and historical observations to reconstruct the glacial history of the Dalla Vedova valley from deglacial time to the present. After deglacial recession into northeastern Darwin and Dalla Vedova, by ~16 ka, evidence indicates a glacial advance at ~13 ka coeval with the Antarctic Cold Reversal. The next robustly dated glacial expansion occurred at 870 ± 60 calendar yr ago (approximately AD 1150), followed by less-extensive dendrochronologically constrained advances from shortly before AD 1836 to the mid-twentieth century. Our record is consistent with most studies within the Cordillera Darwin that show that the Holocene glacial maximum occurred during the last millennium. This pattern contrasts with the extensive early- and mid-Holocene glacier expansions farther north in Patagonia; furthermore, an advance at 870 ± 60 yr ago may suggest out-of-phase glacial advances occurred within the Cordillera Darwin relative to Patagonia. We speculate that a southward shift of westerlies and associated climate regimes toward the southernmost tip of the continent, about 900–800 yr ago, provides a mechanism by which some glaciers advanced in the Cordillera Darwin during what is generally considered a warm and dry period to the north in Patagonia.


1986 ◽  
Vol 25 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Richard F. Madole

Glacial Lake Devlin was an ice-margin lake that formed during Pinedale time when the North Boulder Creek valley glacier blocked the mouth of a tributary near the downvalley limit of glaciation. The lake was about 2 km long and as much as 60 m deep, and was fed by meltwater from small valley glaciers. It accumulated sediment, apparently without interruption, for about 10,000 yr. The inception of Lake Devlin between 23,500 and 21,000 yr B.P. provides a limiting date for the maximum expansion of Pinedale ice, because the lake could not form until the North Boulder Creek glacier had advanced to within 2 km of its downvalley limit. The maximum lowering of timberline, which occurred about 19,000 yr B.P., is assumed to coincide with the Pinedale glacial maximum. Apparent timberline elevations determined from Picea/Pinus pollen ratios suggest that ice-front positions during the time between 23,000 and 19,000 yr B.P. may have been only slightly less extensive than at the Pinedale maximum. Lake Devlin drained catastrophically about 13,000 yr B.P., which was after ice had receded from the outlet area. Pinedale glaciation in the Front Range began about or after 30,000 yr B.P. and final deglaciation occurred between 15,000 and 12,000 yr B.P.


2002 ◽  
Author(s):  
Gregg J. Wiche ◽  
K.G. Guttormson ◽  
S.M. Robinson ◽  
G.B. Mitton ◽  
B.J. Bramer
Keyword(s):  

1938 ◽  
Vol 46 (1) ◽  
pp. 23-51
Author(s):  
Gilbert W. Cooke
Keyword(s):  

1940 ◽  
Vol 5 (4) ◽  
pp. 334-335
Author(s):  
Vladimar Alfred Vigfusson

In recent years, the attention of some archaeologists has been directed to the Canadian Northwest with the expectation of finding some evidence or indication of the early migrations of man on this continent. That man reached North America by Bering Strait from Asia, is generally accepted, but the theory that the migrations took place in late Pleistocene times and by way of an open corridor between the Keewatin ice and the Rockies, requires confirmation. It is significant that Folsom and Yuma points from Saskatchewan, described by E. B. Howard, were found mainly in areas bordering the ancient glacial Lake Regina.As a further contribution to this problem, it seems desirable to present a brief description of a carved stone relic found in gravel in central Saskatchewan about three years ago.The stone was found about seven miles southeast of the town of D'Arcy in a gravel pit located on Sec. 9, Tp. 28, Rge. 18, W. 3rd Meridian, on the north bank of a ravine running east into Bad Lake.


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