scholarly journals Terrain Inventory and Quaternary History of Nahanni map area, Yukon Territory and Northwest Territories

1987 ◽  
Author(s):  
L E Jackson
Keyword(s):  
Northwest Territories ◽  
Yukon Territory ◽  
History Of ◽  
Quaternary History

A Study of Seismic Risk near Pipeline Corridors in Northwestern Canada and Eastern Alaska

1974 ◽  
Vol 11 (1) ◽  
pp. 147-164 ◽  
Author(s):  
A. E. Stevens ◽  
W. G. Milne
Keyword(s):  
Northwest Territories ◽  
Seismic Risk ◽  
Yukon Territory ◽  
Red River ◽  
Contour Maps ◽  
History Of ◽  
Strain Release ◽  
Fort Mcpherson ◽  
Risk Parameters ◽  
Large Earthquakes

Seismic risk in the Yukon Territory and adjacent areas of the western Northwest Territories and eastern Alaska is evaluated from locations and magnitudes of earthquakes in northern Canada and Alaska from 1899 to 1970. Contour maps illustrate strain release and also predicted accelerations on firm soil for return periods of 30, 50, and 100 years. Calculated values of these risk parameters may vary by a factor of two or more from actual values due to the short earthquake history of the region studied, uncertainties in location and magnitude of past large earthquakes, lack of measured ground accelerations in the regions, and the unknown modifying influence of soil and subsoil materials.Seismic risk may be significant for parts of the Mackenzie Valley pipeline corridor in the vicinity of Fort McPherson between mile 700 (east of Arctic Red River, Northwest Territories) and mile 850 (east of Old Crow, Yukon Territory).

Late Quaternary history of black spruce and grasslands in southwest Yukon Territory

1992 ◽  
Vol 70 (7) ◽  
pp. 1336-1345 ◽  
Author(s):  
T. J. Keenan ◽  
L. C. Cwynar
Keyword(s):  
Dominant Species ◽  
Black Spruce ◽  
Late Quaternary ◽  
Minor Component ◽  
White Spruce ◽  
Yukon Territory ◽  
The Past ◽  
History Of ◽  
Quaternary History ◽  
A Minor

Pollen records from Long Last Lake and Two Horsemen Pond, near the centre of the arid region of southwest Yukon Territory, do not support the hypotheses that (i) black spruce was a dominant species in the region and (ii) the southwest Yukon supported widespread grasslands during most of the past 10 000 years. Black spruce became established between 8500 and 8000 BP, shortly after the arrival of white spruce, but its low pollen percentages (< 5%) indicate that it was a minor component of forests. Between 6000 and 5000 BP, white spruce populations decreased as black spruce and green alder increased, but black spruce remained a minor constituent of the forest, never becoming a dominant species as at Kettlehole Pond near the southeast margin of the arid southwest Yukon. The initial vegetation was a poplar woodland, dating from 9200 to 8500 BP at Long Last Lake. At both Long Last Lake and Two Horsemen Pond, the high percentages of herb pollen indicate that the forest was open, but the low values of grass pollen suggest that grasslands were not extensive. Coincident with the establishment of spruce woodland at 8500 BP, pollen of herbs declines and remains comparatively low until 1300 BP when herbs, including grasses, increase to maximum values for the period of record, indicating the grassland communities were probably never more abundant during the Holocene than they are now. Key words: southwest Yukon, black spruce, pollen analysis, paleoecology, climate change.

Late Quaternary history of colluvial deposition and erosion in hollows, central California Coast Ranges

1990 ◽  
Vol 102 (7) ◽  
pp. 969-982 ◽  
Author(s):  
STEVEN L. RENEAU ◽  
WILLIAM E. DIETRICH ◽  
DOUGLAS J. DONAHUE ◽  
A. J. TIMOTHY JULL ◽  
MEYER RUBIN
Keyword(s):  
Late Quaternary ◽  
California Coast ◽  
Central California ◽  
History Of ◽  
Quaternary History ◽  
Coast Ranges ◽  
California Coast Ranges

Life history of tundra-dwelling wolf spiders (Araneae: Lycosidae) from the Yukon Territory, Canada

2012 ◽  
Vol 90 (6) ◽  
pp. 714-721 ◽  
Author(s):  
J.J. Bowden ◽  
C.M. Buddle
Keyword(s):  
Reproductive Effort ◽  
Abiotic Factors ◽  
Wolf Spider ◽  
Local Variation ◽  
Yukon Territory ◽  
The Arctic ◽  
Wolf Spiders ◽  
Female Body Size ◽  
Trade Offs ◽  
History Of

We studied populations of three tundra-dwelling wolf spider (Lycosidae) species to determine reproductive trait relationships and developmental timing in the Arctic. We collected 451 Pardosa lapponica (Thorell, 1872), 176 Pardosa sodalis Holm, 1970, and 117 Pardosa moesta Banks, 1892 during summer 2008. We used log-likelihood ratio tests and multiple linear regressions to determine the best predictors of fecundity and relative reproductive effort. Female body size best explained the variation in fecundity and body condition was the best predictor for relative reproductive effort. We tested for a trade-off between the allocation of resources to individual eggs and the number of eggs produced (fecundity) within each species using linear regression. There was variation in detectable egg size and number trade-offs among sites and these may be related to local variation in resource allocation linked to density-related biotic or abiotic factors. These findings contribute to knowledge about the fitness of arctic wolf spiders in the region of study and are particularly relevant in light of the effects that climate changes are predicted to have on the arctic fauna.

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.

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