THE ROCKY MOUNTAIN TRENCH: A PROBLEM

1964 ◽  
Vol 1 (3) ◽  
pp. 184-205 ◽  
Author(s):  
C. H. Crickmay
Keyword(s):  
Rocky Mountains ◽  
Rocky Mountain ◽  
Canadian Rocky Mountains ◽  
The West ◽  
West Side ◽  
Combined Action ◽  
Headward Erosion

The Rocky Mountain Trench is defined as the 1 000-mile valley which marks the west side of the Canadian Rocky Mountains. The background of the Trench as a problem is examined, and descriptions, geographical and geological, are given. Previous work on Trench origin is reviewed and note is taken of the seeming inapplicability of accepted erosion theories to the making of the erosion-made Trench. An hypothesis is offered in which the combined action of drainage hemmed in by bordering uplifts, guided headward erosion, lateral corrasion, and streams repeatedly reversed by continuing diastrophism is suggested as the excavator of the Trench, a valley characterized by the puzzling peculiarity of continuous depth without a consistent gradient.

Tectonic implications of 40Ar/39Ar muscovite dates from the Mt. Haley stock and Lussier River stock, near Fort Steele, British Columbia

2006 ◽  
Vol 43 (11) ◽  
pp. 1673-1684 ◽  
Author(s):  
Kyle P Larson ◽  
Raymond A Price ◽  
Douglas A Archibald
Keyword(s):  
British Columbia ◽  
Single Crystal ◽  
Rocky Mountains ◽  
Potassium Feldspar ◽  
Canadian Rocky Mountains ◽  
The West ◽  
Lower Paleozoic ◽  
Tectonic Implications ◽  
West Limb ◽  
Step Heating

The Mt. Haley and Lussier River stocks are located northeast of Cranbrook, B.C. near the south end of the Western Main Ranges of the Southern Canadian Rocky Mountains. Both are multiphase, potassium-feldspar porphyritic monzonite plutons that intrude lower Paleozoic miogeoclinal strata. They crosscut and thermally overprint the Lussier River fault and the thrust and fold structures in the east flank of the Purcell anticlinorium and the west limb of the Porcupine Creek anticlinorial fan structure. Muscovite from the Mt. Haley stock yielded a 40Ar/39Ar plateau age of 108.2 ± 0.7 Ma (2σ), and a single-crystal, step-heating analysis of muscovite from a skarn in the metamorphic aureole adjacent to the Lussier River stock gave a plateau date of 108.7 ± 0.6 Ma (2σ). These dates constrain the timing of thrusting and folding in this portion of the western Rocky Mountains and of the displacement along the Lussier River – St. Mary fault to pre-middle Albian.

Conductive structures under the Canadian Rocky Mountains

1985 ◽  
Vol 22 (3) ◽  
pp. 384-398 ◽  
Author(s):  
D. K. Bingham ◽  
D. I. Gough ◽  
M. R. Ingham
Keyword(s):  
Rocky Mountains ◽  
Transfer Functions ◽  
Three Dimensional ◽  
Vertical Component ◽  
Rocky Mountain ◽  
Auroral Zone ◽  
Event Analysis ◽  
Canadian Rocky Mountains ◽  
Period Range ◽  
Single Station

The paper reports results from an array of 33 three-component magnetometers that recorded time-varying fields in 1981 over an area of some 56 000 km2 in the Canadian Cordillera. The array was centred at Tête Jaune Cache in the Rocky Mountain Trench, where a large magnetovariation anomaly had been located in an earlier array study. It was bisected by the trench and extended to the northeast across the Rocky Mountains to the Alberta Foothills and to the southwest across the Cariboo and Monashee mountains. Magnetograms and Fourier transform maps covering the period range 10–91 min show strong attenuation of the vertical component, Z, southwest of the Rocky Mountain Trench, with very large Z amplitudes in the Main Ranges of the Rockies. The horizontal components show an elongated anomaly along the Rocky Mountains Main Ranges and Trench, with three-dimensional features superimposed. The conductive structures include a highly conductive layer, probably in the lower crust, southwest of the trench and a conductive ridge rising into the upper crust near the edge of that layer. Current models have been fitted to observed vertical -and horizontal-component anomalies and show that both layer and ridge are necessary for a fit and that the ridge is 50–80 km wide. Single-station transfer functions at periods of 10 and 22 min have been calculated from a number of variation events of various polarizations, to reduce any displacement of the anomalies by auroral-zone source currents. Artificial-event analysis, with these transfer functions, shows that the conductive ridge lies under the Main Ranges of the Rockies and not under the trench. Its great width indicates a structure of major tectonic significance, which will be considered in another paper.

Distribution and Life History of the Lodgepole Needle Miner (Recurvaria sp.) (Lepidoptera: Gelechiidae) in Canadian Rocky Mountain Parks

1954 ◽  
Vol 86 (1) ◽  
pp. 1-12 ◽  
Author(s):  
R. W. Stark
Keyword(s):  
Life History ◽  
Rocky Mountains ◽  
National Park ◽  
Life Histories ◽  
Rocky Mountain ◽  
Yosemite National Park ◽  
Canadian Rocky Mountains ◽  
History Of

General. The life history of the lodgepole needle miner in Yosemite National Park, California, has been described (24). The Canadian outbreak was discovered in 1942 but intensive investigations were not commenced until 1948. Many differences have been noted between the Canadian and Californian life histories since the discovery of the outbreak.It is the purpose of this paper to bring together all information collected by the author and staff of the Laboratory of Forest Zoology at Calgary, Alberta, concerning the life history of the lodgepole needle miner in the Canadian Rocky mountains.

scholarly journals The Quaternary Geologic History of the Canadian Rocky Mountains

2007 ◽  
Vol 46 (1) ◽  
pp. 5-50 ◽  
Author(s):  
Peter Bobrowsky ◽  
Nathaniel W. Rutter
Keyword(s):  
Central Region ◽  
Rocky Mountains ◽  
Ice Sheet ◽  
Rocky Mountain ◽  
Canadian Rocky Mountains ◽  
Geologic History ◽  
Physical Form ◽  
History Of ◽  
Central Rocky Mountains ◽  
Late Wisconsinan

ABSTRACT The Canadian Rocky Mountains figured prominently during the glacial history of western Canada. First as a western limit or boundary to the Laurentide Ice Sheet, second as an eastern margin of the Cordilleran Ice Sheet, and finally as a centre of local Montane ice. Throughout the Quaternary, complex interactions of glacier ice from these three ice sources markedly changed the physical form of the Rocky Mountains, Trench and Foothills areas. Investigations into the Quaternary history of this region have been ongoing since the beginning of the last century. Since about 1950, the number of studies performed in this area have increased significantly. This paper briefly reviews the historical accomplishments of Quaternary work in the region up to the period of about 1950. From this time to the present, individual study efforts are examined in detail according to the three geographic regions: 1) the northern Rocky Mountains (from the Liard Plateau south to the McGregor Plateau), 2) the central Rocky Mountains (from the McGregor Plateau south to the Porcupine Hills) and 3) the southern Rocky Mountains (from the Porcupine Hills south to the international border). In the northern region, geologic data suggest a maximum of two Rocky Mountain glaciations and only one Laurentide glaciation and no ice coalescence. In the central region, three of four Rocky Mountain events, and at least two Laurentide events are known. Only in the central region is there good evidence for ice coalescence, but the timing of this event is not clearly established. In the south, at least three Rocky Mountain episodes and a variable number of Laurentide episodes are recognized. There is no evidence for ice coalescence. A number of facts support the proposal that Cordilleran ice crossed the Continental Divide and joined with local Montane ice at several locations. However, this expansion of western ice occurred before the Late Wisconsinan in all areas but Jasper. In general, the chronological data presented suggest that the Late Wisconsinan glaciation in the Rocky Mountains was a short-lived event which started around or after 20 ka years ago and ended before 12 ka ago.

Paleomagnetism and age of three Canadian Rocky Mountain diatremes

1992 ◽  
Vol 29 (1) ◽  
pp. 35-47 ◽  
Author(s):  
P. Jane Wynne ◽  
E. Irving ◽  
Daniel J. Schulze ◽  
Douglas C. Hall ◽  
Hewart H. Helmstaedt
Keyword(s):  
North America ◽  
Rocky Mountains ◽  
Rocky Mountain ◽  
Canadian Rocky Mountains ◽  
Early Devonian ◽  
Polar Wander ◽  
Middle Ordovician ◽  
Normal Polarity ◽  
The Cross ◽  
Age Estimates

Paleomagnetic results, and age estimates derived from them, arc presented for three diatremes, using as a basis of comparison the combined apparent polar wander (APW) path for North America and Europe of Van der Voo. The Cross diatreme of the Front Ranges of the Canadian Rocky Mountains has yielded a radiometric age of 241 Ma (earliest Triassic) and is hosted by the flat-lying Pennsylvanian Tunnel Mountain Formation. It has normal polarity magnetization and yields a paleopole correctly placed according to its radiometric age on the APW path. The Blackpool diatreme (for which no radiometric age is available), which is located in the Main Ranges of the Rocky Mountains, is known to be post-Late Ordovician because it is hosted by rocks of that age. It also has magnetization of normal polarity and yields a paleopole that, when calculated with respect to present horizontal, is coincident with the latest Cretaceous to Paleocene paleopole for North America. The paleopole, when calculated with respect to bedding, lies on the Middle Ordovician portion of the combined APW path. A clockwise rotation of 10° brings the paleopole into agreement with the latest Ordovician. Hence, from a paleomagnetic standpoint, a latest Cretaceous to Paleocene or latest Ordovician age is possible. The HP pipe (radiometric age 391 ± 5 Ma or Early Devonian), previously studied by D. T. A. Symons and M. T. Lewchuk, is hosted in limestones of Upper Cambrian to Middle Ordovician age. It has reversed polarity and yields a paleopole that, when compared with the combined APW path, suggests an age of mid-Permian, although errors are such that it could be somewhat younger, roughly coeval with the Cross diatreme. We conclude, therefore, that the radiometric age estimated for the HP pipe could be too old by about 130 million years.

Mitbringsel aus den Ferien

Praxis ◽  
2005 ◽  
Vol 94 (47) ◽  
pp. 1869-1870
Author(s):  
Balestra ◽  
Nüesch
Keyword(s):  
Rocky Mountains ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Rickettsia Conorii ◽  
Rocky Mountain Spotted Fever ◽  
Klinische Diagnose ◽  
Rickettsia Rickettsii

Eine 37-jährige Patientin stellt sich nach der Rückkehr von einer Rundreise durch Nordamerika mit einem Status febrilis seit zehn Tagen und einem makulösem extremitätenbetontem Exanthem seit einem Tag vor. Bei suggestiver Klinik und Besuch der Rocky Mountains wird ein Rocky Mountain spotted fever diagnostiziert. Die Serologie für Rickettsia conorii, die mit Rickettsia rickettsii kreuzreagiert, war positiv und bestätigte die klinische Diagnose. Allerdings konnte der beweisende vierfache Titeranstieg, möglicherweise wegen spät abgenommener ersten Serologie, nicht nachgewiesen werden. Nach zweiwöchiger antibiotischer Therapie mit Doxycycline waren Status febrilis und Exanthem regredient.

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