scholarly journals Taxonomy and biostratigraphy of Llandovery [silurian] conodonts in the Canadian Cordillera, northern Yukon Territory

1991 ◽  
Author(s):  
A D McCracken
Keyword(s):  
Yukon Territory ◽  
Canadian Cordillera

Evidence for a 55–50 ka (early Wisconsin) glaciation of the Cordilleran ice sheet, Yukon Territory, Canada

2007 ◽  
Vol 68 (1) ◽  
pp. 141-150 ◽  
Author(s):  
Brent C. Ward ◽  
Jeffrey D. Bond ◽  
John C. Gosse
Keyword(s):  
Ice Sheet ◽  
Yukon Territory ◽  
Canadian Cordillera ◽  
Aleutian Low ◽  
Climatic Forcing ◽  
Apparent Contrast ◽  
Oxygen Isotope Stage ◽  
Source Areas ◽  
Cordilleran Ice Sheet ◽  
Exposure Ages

AbstractCosmogenic 10Be ages on boulders of 54–51 ka (n=4) on a penultimate Cordilleran ice sheet (CIS) drift confirm that Marine Oxygen Isotope Stage (MIS) 4 (early Wisconsin) glaciation was extensive in parts of Yukon Territory, the first confirmed evidence in the Canadian Cordillera. We name the glaciation inferred from the mapped and dated drift the Gladstone. These results are in apparent contrast to the MIS 6 (Illinoian) age of the penultimate Reid glaciation to the east in central Yukon but are equivalent to exposure ages on MIS 4 drift in Alaska. Contrasting penultimate ice extents in Yukon requires that different source areas of the northern CIS in Yukon responded differently to climatic forcing during glaciations. The variation in glacier extent for different source areas likely relates to variation in precipitation during glaciation, as the northern CIS was a precipitation-limited system. Causes for a variation in precipitation remain unclear but likely involve the style of precipitation delivery over the St. Elias Mountains possibly related to variations in the Aleutian low.

Paleomagnetic and geobarometric study of the mid-Cretaceous Whitehorse Pluton, Yukon Territory

1997 ◽  
Vol 34 (10) ◽  
pp. 1379-1391 ◽  
Author(s):  
M. J. Harris ◽  
D. T. A. Symons ◽  
W. H. Blackburn ◽  
C. J. R. Hart
Keyword(s):  
United States ◽  
British Columbia ◽  
Crystallization Temperature ◽  
Remanent Magnetization ◽  
Average Rate ◽  
Yukon Territory ◽  
Canadian Cordillera ◽  
The North ◽  
North American Craton ◽  
High Level

This is the first of several Lithoprobe paleomagnetic studies underway to examine geotectonic motions in the northern Canadian Cordillera. Except for one controversial study, estimates for terranes underlying the Intermontane Belt in the Yukon have been extrapolated from studies in Alaska, southern British Columbia, and the northwestern United States. The Whitehorse Pluton is a large unmetamorphosed and undeformed tonalitic body of mid-Cretaceous age (~112 Ma) that was intruded into sedimentary units of the Whitehorse Trough in the Stikinia terrane. Geothermobarometric estimates for eight sites around the pluton indicate that postmagnetization tilting has been negligible since cooling through the hornblende-crystallization temperature and that the pluton is a high-level intrusion. Paleomagnetic measurements for 22 of 24 sites in the pluton yield a well-defined characteristic remanent magnetization (ChRM) direction that is steeply down and northwards. The ChRM direction gives a paleopole of 285.5°E, 81.7°N (dp = 53°, dm = 5.7°). When compared with the 112 Ma reference pole for the North American craton, this paleopole suggests that the northern Stikinia terrane has been translated northwards by 11.0 ± 4.8° (1220 ± 530 km) and rotated clockwise by 59 ± 17°. Except for an estimate from the ~70 Ma Carmacks Group volcanics, this translation and rotation estimate agrees well with previous estimates for units in the central and southern Intermontane Belt. They suggest that the terranes of the Intermontane Belt have behaved as a fairly coherent unit since the Early Cretaceous, moving northward at a minimum average rate of 2.3 ± 0.4 cm/a between ~140 and ~45 Ma.

New occurrences of two Lower Devonian graptolites from northern Yukon

1979 ◽  
Vol 16 (5) ◽  
pp. 1121-1124 ◽  
Author(s):  
Alfred C. Lenz
Keyword(s):  
Lower Devonian ◽  
Yukon Territory ◽  
Canadian Cordillera ◽  
Early Devonian ◽  
First Time ◽  
Richardson Mountains ◽  
New Occurrences

Two species of Early Devonian graptolites are described from the Richardson Mountains, northern Yukon Territory; these are ?Pristiograptus sp. and Monograptus fanicus Koren', the latter being reported for the first time from the northern Canadian Cordillera. Associated grapto lites as well as the presence of M. fanicus indicate a Pragian age. The presence of M. fanicus helps fill the zonal gap between the late Lochkovian hercyniens Zone, and probable late Pragian thomasi and yukonensis Zones, and suggests that lower and upper Pragian substage divisions are possibly recognizable in the graptoiite facies.

Source and redox controls on metallogenic variations in intrusion-related ore systems, Tombstone-Tungsten Belt, Yukon Territory, Canada

2004 ◽  
Vol 95 (1-2) ◽  
pp. 339-356 ◽  
Author(s):  
Craig J. R. Hart ◽  
John L. Mair ◽  
Richard J. Goldfarb ◽  
David I. Groves
Keyword(s):  
Redox State ◽  
Yukon Territory ◽  
Canadian Cordillera ◽  
Enriched Mantle ◽  
Granitic Intrusions ◽  
Skarn Deposits ◽  
World Class ◽  
Lower Temperature ◽  
Source Materials ◽  
Pelitic Rocks

ABSTRACTThe Tombstone, Mayo and Tungsten plutonic suites of granitic intrusions, collectively termed the Tombstone-Tungsten Belt, form three geographically, mineralogically, geochemically and metallogenically distinct plutonic suites. The granites (sensu lato) intruded the ancient North American continental margin of the northern Canadian Cordillera as part of a single magmatic episode in the mid-Cretaceous (96–90 Ma). The Tombstone Suite is alkalic, variably fractionated, slightly oxidised, contains magnetite and titanite, and has primary, but no xenocrystic, zircon. The Mayo Suite is sub-alkalic, metaluminous to weakly peraluminous, fractionated, but with early felsic and late mafic phases, moderately reduced with titanite dominant, and has xenocrystic zircon. The Tungsten Suite is peraluminous, entirely felsic, more highly fractionated, reduced with ilmenite dominant, and has abundant xenocrystic zircon. Each suite has a distinctive petrogenesis. The Tombstone Suite was derived from an enriched, previously depleted lithospheric mantle, the Tungsten Suite is from the continental crust including, but not dominated by, carbonaceous pelitic rocks, and the Mayo Suite is from a similar sedimentary crustal source, but is mixed with a distinct mafic component from an enriched mantle source.Each suite has a distinctive metallogeny that is related to the source and redox characteristics of the magma. The Tombstone Suite has a Au-Cu-Bi association that is characteristic of most oxidised and alkalic magmas, but also has associated, and enigmatic, U-Th-F mineralisation. The reduced Tungsten Suite intrusions are characterised by world-class tungsten skarn deposits with less significant Cu, Zn, Sn and Mo anomalies. The Mayo Suite intrusions are characteristically gold-enriched, with associated As, Bi, Te and W associations. All suites also have associated, but distal and lower temperature Ag-Pb- and Sb-rich mineral occurrences. Although processes such as fractionation, volatile enrichment and phase separation are ultimately required to produce economic concentrations of ore elements from crystallising magmas, the nature of the source materials and their redox state play an important role in determining which elements are effectively concentrated by magmatic processes

K-Ar Dating of the 'Cork' (Burwash Creek) Cu-Mo Prospect, Burwash Landing Area, Yukon Territory

1972 ◽  
Vol 9 (7) ◽  
pp. 918-921 ◽  
Author(s):  
P. A. Christopher ◽  
W. H. White ◽  
J. E. Harakal
Keyword(s):  
Yukon Territory ◽  
Canadian Cordillera ◽  
Early Tertiary ◽  
Apparent Age ◽  
Radiometric Determination

A 26 ± 0.3 m.y. mean age was determined for quartz latite porphyry near Burwash Creek, Yukon Territory. This apparent age for mineralized porphyry represents the youngest documented porphyry prospect in the Canadian Cordillera. Cretaceous ages determined for Kluane Range intrusions agree with geologic evidence, and early Tertiary ages from the Ruby Range batholith agree with a previous radiometric determination.

Summary terrane, mineral deposit, and metallogenic belt maps of the Russian Far East, Alaska, and the Canadian Cordillera

1998 ◽  
Author(s):  
Warren J. Nokleberg ◽  
Timothy D. West ◽  
Kenneth M. Dawson ◽  
Vladimir I. Shpikerman ◽  
Thomas K. Bundtzen ◽  
...  
Keyword(s):  
Russian Far East ◽  
Far East ◽  
Mineral Deposit ◽  
Canadian Cordillera ◽  
Metallogenic Belt ◽  
The Russian Far East

Mineral deposit and metallogenic belt maps of the Russian Far East, Alaska, and the Canadian cordillera

1997 ◽  
Author(s):  
Warren J. Nokleberg ◽  
Timothy D. West ◽  
Kenneth M. Dawson ◽  
Vladimir I. Shpikerman ◽  
Thomas K. Bundtzen ◽  
...  
Keyword(s):  
Russian Far East ◽  
Far East ◽  
Mineral Deposit ◽  
Canadian Cordillera ◽  
Metallogenic Belt ◽  
The Russian Far East
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