Frost mounds at Bear Rock, near Fort Norman, Northwest Territories, 1975–1976

1978 ◽  
Vol 15 (2) ◽  
pp. 263-276 ◽  
Author(s):  
Robert O. van Everdingen
Keyword(s):  
Northwest Territories ◽  
Soil Cover ◽  
Yukon Territory ◽  
East Side ◽  
Frozen Ground ◽  
North Fork ◽  
Spring Area ◽  
Empty Cavity ◽  
Blackstone River ◽  
Large Flow

A number of frost mounds of the frost blister type were observed at the site of a group of cold springs on the east side of Bear Rock, about 4 km west-northwest of Fort Norman, Northwest Territories, Canada. The mounds ranged in height from 2.0 to 3.0 m, with horizontal dimensions between 26 and 48 m. They contained a domed layer of ice, up to 85 cm thick, over an empty cavity up to 70 cm high, which was in turn underlain by frozen ground. Soil cover over the ice layer was 30–65 cm thick. The ice presumably formed from springwater injected under considerable hydraulic potential. New frost blisters are formed annually. Three recent frost blisters observed in June 1975 were partially destroyed by melting, slumping of the soil cover, and collapse of the ice dome by mid-September 1975. A portion of the ice lasted into summer 1976. Three new frost blisters, formed during the 1975–1976 winter, were observed in March 1976; two of these had completely collapsed by mid-June. An icing blister associated with one of them ruptured on March 21, 1976, producing a large flow of water, which lasted for several hours. A section of the icing blister subsequently subsided. Remnants of frost blisters have been observed in a spring area northeast of Turton Lake, Northwest Territories, and along the Dempster Highway in North Fork Pass and near the crossing of Blackstone River, Yukon Territory.

Middle and Late Ordovician conodont faunas and biostratigraphy of graptolitic strata of the Road River Group, northern Yukon Territory

1987 ◽  
Vol 24 (4) ◽  
pp. 643-653 ◽  
Author(s):  
Alexander D. McCracken ◽  
Alfred C. Lenz
Keyword(s):  
Northwest Territories ◽  
Cold Water ◽  
Late Ordovician ◽  
Yukon Territory ◽  
Warm Water ◽  
Rare Occurrence ◽  
Carbonate Facies ◽  
The Road ◽  
Fine Grained ◽  
Blackstone River

Ordovician conodont faunas from the fine-grained clastic Road River Group in northern Yukon Territory contain a mixture of species from both warm- and cold-water regions. This group in southwestern Northwest Territories also has mixed faunas, whereas conodonts from the carbonate facies are more characteristic of the warm-water regions.Six conodont associations and biozones are identified from the Yukon. Some, such as the early Llanvirn "Cordylodus" horridus – Spinodus spinatus association, contain reworked elements. The Pygodus serra Zone (middle–late Llanvirn) is within the upper P. tentaculatus Zone and well below the G. euglyphus Zone. Genera include Ansella, Periodon, Protopanderodus, Pygodus, and Walliserodus.At Peel River, conodonts are within the P. pacificus Zone. The Blackstone River conodonts occur above the P. pacificus Zone and below the G. persculptus Zone (?) and include Oulodus rohneri, Plectodina florida, and Noixodontus. Amorphognathus ordovicicus, Gamachignathus ensifer, O. ulrichi, and Plectodina tenuis occur in both faunas. These represent Fauna 12, found in late Richmondian strata, rather than the Gamachian Fauna 13 and are assigned to the G. ensifer Zone; both occurrences of G. ensifer are biohorizons. The C.? extraordinarius and G. persculptus zones are not recognized at Peel and Rock rivers and Tetlit Creek.The Ozarkodina n. sp. A – Icriodella sp. B association occurs at Pat Lake between the G. persculptus Zone (?) and the underlying P. pacificus Zone. The Ozarkodina have a Silurian aspect but must be regarded as Ordovician.The Ordovician–Silurian boundary in the Road River Group of the Yukon is best defined using graptolites because of the rare occurrence of conodonts.

The sequence and correlation of Early Ordovician (Arenig) graptolite faunas in the Richardson Trough and Misty Creek Embayment, Yukon Territory and District of Mackenzie, Canada

2006 ◽  
Vol 43 (12) ◽  
pp. 1791-1820 ◽  
Author(s):  
D E Jackson ◽  
A C Lenz
Keyword(s):  
Northwest Territories ◽  
Deep Water ◽  
Yukon Territory ◽  
Early Ordovician ◽  
The Road ◽  
Bedded Chert ◽  
First Occurrence ◽  
Mackenzie Mountains ◽  
First Time

Four graptolite biozones are recorded from the Arenig portion of the Road River Group in the Richardson and Mackenzie mountains in the Yukon and Northwest Territories. In ascending order, these zones are Tetragraptus approximatus, Pendeograptus fruticosus, Didymograptus bifidus, and Parisograptus caduceus australis (new). The Castlemainian stage may be represented by nongraptolitic massive bedded chert. The Arenig–Llanvirn boundary is drawn below the first occurrence of Undulograptus austrodentatus. Fifty-four graptolite taxa are present, and 16 of these species and subspecies are recorded for the first time in this deep-water biotope, namely, Didymograptus? cf. adamantinus, D. asperus, D. dilatans, D. cf. kurcki, D. validus communis, Holmograptus aff. leptograptoides, H. sp. A, Isograptus? sp. nov. A, I. ? dilemma, Keblograptus geminus, Pseudisograptus manubriatus harrisi, Ps. m. koi, Ps. m. janus, Ps. cf. tau, Xiphograptus lofuensis, and Zygograptus cf. abnormis.

scholarly journals 2005 reconnaissance field program in Peel Plateau and Peel Plain region, Northwest Territories and Yukon Territory

2006 ◽  
Author(s):  
L J Pyle ◽  
A L Jones ◽  
L P Gal ◽  
J G Abbott ◽  
A D McCracken ◽  
...  
Keyword(s):  
Northwest Territories ◽  
Yukon Territory ◽  
Plain Region ◽  
Peel Plateau

Permafrost, tectonics, and past and future regional climate change, Yukon and adjacent Northwest Territories

1994 ◽  
Vol 31 (1) ◽  
pp. 182-191 ◽  
Author(s):  
C. R. Burn
Keyword(s):  
Northwest Territories ◽  
General Circulation ◽  
Regional Climate ◽  
Gulf Of Alaska ◽  
General Circulation Models ◽  
Yukon Territory ◽  
Early Pleistocene ◽  
Tectonic Activity ◽  
Near Surface ◽  
Late Tertiary

Late Tertiary changes in the general circulation of the atmosphere, regionally enhanced by uplift of the Wrangell – Saint: Elias and Coast mountains, were sufficient to promote permafrost development in the western Arctic. Permafrost developed in Yukon Territory and adjacent Northwest Territories during early Pleistocene glacial periods, after continued tectonic activity led to further modification of regional climate, but degraded in the interglacials. Permafrost has been present in northern parts of the region since the Illinoian glaciation, but most ground ice in central Yukon formed in the Late Wisconsinan. The present interglacial is the only one with widespread evidence of permafrost, which is maintained in the valleys of central and southern Yukon by the Saint Elias Mountains blocking continental penetration of maritime air from the Gulf of Alaska. This reduces snow depth in winter, while cold-air drainage in the dissected terrain of the Yukon Plateaus enhances the near-surface inversion, leading to continental minimum temperatures. General circulation models used to simulate climate represent the physiography of northwest Canada crudely. As a result, the simulations are unable to reproduce conditions responsible for the development and preservation of permafrost in the region.

scholarly journals Spatially distributed tracer-aided runoff modelling and dynamics of storage and water ages in a permafrost-influenced catchment

2019 ◽  
Vol 23 (6) ◽  
pp. 2507-2523 ◽  
Author(s):  
Thea I. Piovano ◽  
Doerthe Tetzlaff ◽  
Sean K. Carey ◽  
Nadine J. Shatilla ◽  
Aaron Smith ◽  
...  
Keyword(s):  
Snow Water Equivalent ◽  
Temporal Dynamics ◽  
Snow Accumulation ◽  
Yukon Territory ◽  
Distributed Model ◽  
Runoff Generation ◽  
Frozen Ground ◽  
Isotope Data ◽  
Spatially Distributed ◽  
Thaw Layer

Abstract. Permafrost strongly controls hydrological processes in cold regions. Our understanding of how changes in seasonal and perennial frozen ground disposition and linked storage dynamics affect runoff generation processes remains limited. Storage dynamics and water redistribution are influenced by the seasonal variability and spatial heterogeneity of frozen ground, snow accumulation and melt. Stable isotopes are potentially useful for quantifying the dynamics of water sources, flow paths and ages, yet few studies have employed isotope data in permafrost-influenced catchments. Here, we applied the conceptual model STARR (the Spatially distributed Tracer-Aided Rainfall–Runoff model), which facilitates fully distributed simulations of hydrological storage dynamics and runoff processes, isotopic composition and water ages. We adapted this model for a subarctic catchment in Yukon Territory, Canada, with a time-variable implementation of field capacity to include the influence of thaw dynamics. A multi-criteria calibration based on stream flow, snow water equivalent and isotopes was applied to 3 years of data. The integration of isotope data in the spatially distributed model provided the basis for quantifying spatio-temporal dynamics of water storage and ages, emphasizing the importance of thaw layer dynamics in mixing and damping the melt signal. By using the model conceptualization of spatially and temporally variable storage, this study demonstrates the ability of tracer-aided modelling to capture thaw layer dynamics that cause mixing and damping of the isotopic melt signal.

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