scholarly journals Coates Lake Group in the Arctic Red River area, northern Mackenzie Mountains, Northwest Territories

2020 ◽  
Author(s):  
K M Fallas
2007 ◽  
Vol 81 (6) ◽  
pp. 1348-1364 ◽  
Author(s):  
Margaret J. Campbell ◽  
Brian D. E. Chatterton

Four new species of Borealarges, B. fritillus, B. patulus, B. renodis, and B. variabilis, and one new species of Richterarges, R. facetus, are described and one unnamed species, Borealarges sp., discussed. All are from the Wenlock strata of Avalanche Lake sections in the Mackenzie Mountains, Northwest Territories. Borealarges tuckerae Adrain, 1994, the only species reported from both the Arctic and the Mackenzie Mountains, is discussed. Hemiarges avalanchensis n. sp., an Ashgill species from Avalanche Lake section AV 4B just below the Ordovician-Silurian boundary, is described. A phylogenetic analysis based on 14 species of Borealarges, three of Richterarges, and two of Hemiarges, demonstrates that the former two genera are three separate and distinct taxa. Borealarges, a genus that includes some species formerly assigned to Richterarges or Hemiarges, is monophyletic, contains a well-supported internal clade of species, and is not separated into senso stricto and senso lato groupings.


ARCTIC ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 42-50
Author(s):  
Kris W.C. Maier ◽  
Neil J. Mochnacz ◽  
Robert Bajno ◽  
Andrew J. Chapelsky ◽  
Peter Rodger ◽  
...  

Northern form Dolly Varden is an anadromous char with significant ecological value found in high-gradient rivers of the Western Arctic. Because of declines in population abundance, Dolly Varden was recently designated as “Special Concern” under the federal Species at Risk Act. This species is also of great cultural and dietary significance to Indigenous Peoples of many communities in the Western Arctic; thus, expanding knowledge of the distribution, biology, and essential habitat is an important priority. We present results of a fisheries survey in the headwaters of the Arctic Red River, Northwest Territories, that focused on confirming the presence of Dolly Varden. Of 143 fish captured among 12 sampling locations, two were Arctic grayling (Thymallus arcticus), 33 were slimy sculpin (Cottus cognatus), and 108 were char identified using qualitative and quantitative morphological features. A subsample of 44 char voucher specimens were frozen whole and later identified using a linear discriminant function (LDF) based on meristic counts and morphological measurements, and a mitochondrial DNA genetic marker. LDF scores indicated that char collected in the Arctic Red River were northern form Dolly Varden. Genetic analysis showed that all but one char possessed mitochondrial DNA sequences common in northern form Dolly Varden from Canada. Our results confirm the presence of Dolly Varden in the Arctic Red River headwaters, extending the confirmed known distribution of this taxon in the Northwest Territories approximately 450 km south and 100 km east of previously delimited areas.


1978 ◽  
Vol 15 (7) ◽  
pp. 1205-1207 ◽  
Author(s):  
Douglas A. Archibald ◽  
Alan H. Clark ◽  
Edward Farrar ◽  
U Khin Zaw

K–Ar dating of magmatic biotite, and of hydrothermal biotite and muscovite, demonstrates that quartz monzonite intrusion and exoskarn scheelite mineralization at Cantung, N.W.T., took place over a brief interval in the Upper Cretaceous (ca. 91 Ma). The regional age relationships of magmatic and ore-forming activity in the Logan–Mackenzie Mountains are poorly defined, but it is tentatively inferred that tungsten mineralization may have been related to a late stage in the plutonic development of the area.


1974 ◽  
Vol 52 (4) ◽  
pp. 701-705 ◽  
Author(s):  
William Campbell Steere ◽  
Zennoske Iwatsuki

The name Pseudoditrichum mirabile Steere et Iwatsuki is proposed for a minute moss with leafy stem 1-3 mm high and seta 6 mm long; it was collected on calcareous silt near the Sloan River, Great Bear Lake, Northwest Territories, only a few miles south of the Arctic Circle. The gametophytic characters agree well with those of the Ditrichaceae, a relatively primitive family, but the peristome is clearly double, with the inner and outer teeth opposite, which thereby indicates a much more advanced phylogenetic position, perhaps at the evolutionary level of the Funariaceae. As the combination of gametophytic and sporophytic characteristics exhibited by this moss does not occur in any existing family of mosses, it is therefore deemed necessary to create the new family Pseudoditrichaceae for the new genus and species described here.


1984 ◽  
Vol 48 (1) ◽  
pp. 156 ◽  
Author(s):  
N. M. Simmons ◽  
M. B. Bayer ◽  
L. O. Sinkey

1990 ◽  
Vol 27 (1) ◽  
pp. 129-144 ◽  
Author(s):  
P. K. Kaiser ◽  
J. V. Simmons

The transport mechanism of some rock avalanches of the Mackenzie Mountains in the Yukon and Northwest Territories of Canada is reassessed on the basis of evidence collected during fieldwork and by comparison with results from numerical simulations of the debris flow mechanism. A new hypothesis of glaciation-related transport is advanced as an alternate explanation of apparently very mobile rock avalanches with anomalous travel distances. By the example of the Avalanche Lake slide, it is demonstrated that the debris was most likely not deposited on the current topography but on valley glacier ice at an elevation of about 400–500 m above the valley bottom. This conclusion is supported by field evidence, an empirical runup relationship, and the results from numerical flow simulations. A qualitative interpretation of other debris deposits suggests that several events in the Mackenzie Mountains can be interpreted in the same manner. Key words: rock avalanches, rock slides, debris transport, debris flow modelling, Mackenzie Mountains, Northwest Territories.


2006 ◽  
Vol 43 (12) ◽  
pp. 1791-1820 ◽  
Author(s):  
D E Jackson ◽  
A C Lenz

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.


Polar Record ◽  
2009 ◽  
Vol 46 (2) ◽  
pp. 157-177 ◽  
Author(s):  
Tristan Pearce ◽  
Barry Smit ◽  
Frank Duerden ◽  
James D. Ford ◽  
Annie Goose ◽  
...  

ABSTRACTClimate change is already being experienced in the Arctic with implications for ecosystems and the communities that depend on them. This paper argues that an assessment of community vulnerability to climate change requires knowledge of past experience with climate conditions, responses to climatic variations, future climate change projections, and non-climate factors that influence people's susceptibility and adaptive capacity. The paper documents and describes exposure sensitivities to climate change experienced in the community of Ulukhaktok, Northwest Territories and the adaptive strategies employed. It is based on collaborative research involving semi-structured interviews, secondary sources of information, and participant observations. In the context of subsistence hunting, changes in temperature, seasonal patterns (for example timing and nature of the spring melt), sea ice and wind dynamics, and weather variability have affected the health and availability of some species of wildlife important for subsistence and have exacerbated risks associated with hunting and travel. Inuit in Ulukhaktok are coping with these changes by taking extra precautions when travelling, shifting modes of transportation, travel routes and hunting areas to deal with changing trail conditions, switching species harvested, and supplementing their diet with store bought foods. Limited access to capital resources, changing levels of traditional knowledge and land skills, and substance abuse were identified as key constraints to adaptation. The research demonstrates the need to consider the perspectives and experiences of local people for climate change research to have practical relevance to Arctic communities such as for the development and promotion of adaptive strategies.


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