scholarly journals Stratigraphy, structure and tectonic evolution of southern Pelly Mountains in the Indigo Lake area, Yukon Territory

1981 ◽  
Author(s):  
S P Gordey
Keyword(s):  
Tectonic Evolution ◽  
Yukon Territory ◽  
Lake Area

Comparison of capture–recapture estimators of snowshoe hare populations

1994 ◽  
Vol 72 (10) ◽  
pp. 1800-1807 ◽  
Author(s):  
John Boulanger ◽  
Charles J. Krebs
Keyword(s):  
Population Size ◽  
Yukon Territory ◽  
Robust Estimator ◽  
Snowshoe Hare ◽  
Lake Area ◽  
Island Populations ◽  
Snowshoe Hares ◽  
Population Size Estimates ◽  
Size Population ◽  
Capture Recapture

We used two island populations of snowshoe hares (Lepus americanus) in the Kluane Lake area of the Yukon Territory of Canada to evaluate capture – recapture estimators. These islands were intensively sampled, allowing us to enumerate the actual population size. Population size estimates were calculated using the programs CAPTURE and JOLLY, and estimators were compared for bias characteristics. Results from both islands suggest that the CAPTURE heterogeneity models Mh (jackknife), Mh (Chao), and Mth (time – heterogeneity) and the Jolly – Seber model were approximately unbiased. All other CAPTURE models displayed a negative bias. The CAPTURE model selection routine picked estimation models of different biases for each trapping period, an undesirable result. We conclude that it is best to use one robust estimator such as the Mh (jackknife) with snowshoe hare data.

U–Pb geochronology of late Neoarchean tonalites in the Flin Flon Belt, Trans-Hudson Orogen: surprise at surface

1994 ◽  
Vol 31 (12) ◽  
pp. 1785-1790 ◽  
Author(s):  
J. David ◽  
E. C. Syme
Keyword(s):  
Shear Zone ◽  
Tectonic Evolution ◽  
Volcanic Belt ◽  
Lake Area ◽  
Magmatic Rocks ◽  
Flin Flon ◽  
First Time

The Flin Flon volcanic belt of the Trans-Hudson Orogen in northern Manitoba comprises magmatic rocks (1.88 – 1.90 Ga) generated in an intra-oceanic arc and identified as one of the best examples of juvenile Paleoproterozoic crust. In the Flin Flon – Athapapuskow Lake area, the belt consists of a series of fault-bounded blocks, each having distinct stratigraphic and magmatic affinities, juxtaposed to form an accretionary collage. Two tonalitic bodies within the Northeast Arm shear zone, a major deformation corridor separating two of the most important blocks in the area, have been dated by the U–Pb zircon method at [Formula: see text] and [Formula: see text]. These results indicate the presence of fragments of late Neoarchean crust within the Flin Flon belt, possibly related to ca. 2.5 Ga granitic bodies found in terranes beyond the western limit of the belt. The presence of ca. 2.5 Ga tonalites within the Flin Flon Belt, herein reported for the first time, has major implications for basement involvement in the early tectonic evolution of the Flin Flon Belt.

Landslides at the south end of Kluane Lake, Yukon Territory

1981 ◽  
Vol 18 (5) ◽  
pp. 959-971 ◽  
Author(s):  
John J. Clague
Keyword(s):  
Debris Flows ◽  
Yukon Territory ◽  
Alluvial Fans ◽  
Lake Area ◽  
Slope Failures ◽  
The South ◽  
Glacial Sediments ◽  
Gravel Beds ◽  
Steep Slopes ◽  
Kluane Lake

Landslides are unusually varied and abundant in the Kluane Ranges near the south end of Kluane Lake, Yukon Territory. Selected landslides were investigated to determine the likelihood and probable character of future mass movements in this area, and to gain some understanding of similar but unstudied features elsewhere in the St. Elias Mountains.Landslides in the study area include slumps and related complex landslides, rockfalls, rockslides, rockfall avalanches, and debris flows. The youngest and most spectacular of the large catastrophic landslides is the Sheep Mountain rockfall avalanche (5–10 × 106 m3), which formed as a result of two separate failures between 500 and 1950 radiocarbon years ago. Much of the low mountain slope southwest of this landslide to near the mouth of Slims River is covered by thick blocky rubble deposited during one or more older catastrophic slope failures. Both the Sheep Mountain landslide and the set of older slope failures to the southwest apparently occurred when Kluane Lake was much smaller than it is today. As the level of the lake rose in response to aggradation accompanying the Neoglacial advance of Kaskawulsh Glacier, distal portions of these landslides were inundated.Debris flows and debris torrents occur sporadically on fans in the study area. These fans are composed of diamicton and gravel beds separated by loess layers and paleosols. Marker horizons, such as the Slims Soil (Hypsithermal) and White River tephra (ca. 1200 years BP), occur in these sediments and provide evidence that the fans have been active throughout the Holocene.Contributing factors to landslides in the eastern Kluane Ranges include high seismicity, the presence of steep slopes in pervasively fractured and faulted rocks, an abundance of talus and glacial sediments available for remobilization as debris flows and debris torrents, and the occurrence of intense rainstorms.Although landslides are ubiquitous in the south Kluane Lake area, most of the large deep-seated bedrock failures are relatively old. Thus the danger posed by future comparable landslides to life and property in the area could be considered to be low. Floods, debris flows, and debris torrents on active alluvial fans and aprons skirting the Kluane Ranges probably are greater potential hazards to economic development of this region.

Hettangian (Lower Jurassic) rocks and faunas, northern Yukon Territory

1977 ◽  
Vol 14 (1) ◽  
pp. 89-101 ◽  
Author(s):  
Hans Frebold ◽  
T. P. Poulton
Keyword(s):  
Canadian Arctic ◽  
Lower Jurassic ◽  
Yukon Territory ◽  
Lake Area ◽  
Jurassic Rocks ◽  
First Time

The Lower Jurassic Hettangian Stage is documented with certainty for the first time in the Canadian Arctic. It is represented by a basal Jurassic sandstone unit in the Bonnet Lake area of northern Yukon Territory. The two subzones of the Early Hettangian Planorbis Zone, i.e., the Planorbis Subzone and the Johnstoni Subzone, are indicated by poorly preserved Psiloceras sp. indet. and Psiloceras (Caloceras) cf. P. (C.) johnstoni (J. de C. Sowerby), respectively. The varied but poorly preserved bivalve fauna associated with P. (C.) cf. P. (C.) johnstoni includes Prosogyrotrigonia (?) sp. cf. P. inouyei (Yehara), Cardinia sp. cf. C. hybrida (J. Sowerby), C. sp. aff. C. concinna (J. Sowerby), Pleuromya (?) sp., Meleagrinella (?) sp., Oxytoma (Oxytoma) sp., and Parallelodon (?) sp. The bivalves closely resemble approximately coeval forms described from Japan. The above-mentioned faunas are figured as is a specimen of Psiloceras cf. P. erugatum (Phillips), which was previously described from the Hettangian of southern Yukon. Other occurrences of the Hettangian in Canada and Alaska are reviewed.

scholarly journals First Report of Inonotus tomentosus, the Cause of Tomentosus Root Disease, from the Yukon Territory

Plant Disease ◽  
1998 ◽  
Vol 82 (2) ◽  
pp. 264-264 ◽  
Author(s):  
R. S. Hunt ◽  
T. White
Keyword(s):  
Picea Glauca ◽  
Personal Communication ◽  
Yukon Territory ◽  
Root Disease ◽  
Lake Area ◽  
Diagnostic Features ◽  
Living Tree ◽  
Root Decay ◽  
The Pacific ◽  
Decay Pattern

During forest pest surveys in the Watson Lake area (60°N 129°W) of the Yukon Territory (YT), sporocarps, tentatively identified as Inonotus tomentosus (Fr.:Fr.) S. Teng, were observed in association with old mortality (25+ years) and root rot of old (200 to 275 years) white spruce (Picea glauca (Moench) Voss) growing in riparian zones. I. tomentosus primarily attacks spruce throughout North America (1). Cultures from collected sporocarps and from a decayed root of a living tree produced chlamydospore-like hyphal swellings typical of I. tomentosus(2). Although three of the collected sporocarps were bracketlike, none bore hooked hymenial setae, typical of I. circinatus (Fr.) R. L. Gilbertson. All sporocarps collected possessed straight setal hyphae and were confirmed as I. tomentosus (1). These specimens are filed at the Pacific Forestry Centre herbarium as DAVFP 25375 and DAVFP 25376. This is the first western Canadian report of this major conifer root disease north of about 55°N latitude. Sporocarps have been collected at about the same latitude as Watson Lake, but from 21° farther west, near Fairbanks and Anchorage, AK (L. Trummer, USDA For. Serv. Anchorage, AK, personal communication). For several years, other stump and root decay samples have been collected in the YT as far west as Haines Junction (about halfway between Anchorage and Watson Lake), but the pathogen has never been successfully cultured nor sporocarps collected. Because the decay pattern can be confused with that caused by Phellinus pini (Thore:Fr.) A. Ames, and other diagnostic features were lacking, there has been a reluctance to accept that I. tomentosus is present in the YT. However, it seems likely that I. tomentosus is much more widespread north of 55°N in western Canada than has previously been recognized. References: (1) R. L. Gilbertson and L. Ryvarden. North Am. Polypores. Fungiflora 1:403, 1986. (2) R. S. Hunt. Can. J. Plant Pathol. 19:307, 1997.

Sign in / Sign up

Export Citation Format

Share Document