Stability analysis of a horizontal coalbed methane well in the Rocky Mountain Front Ranges of southeast British Columbia, Canada

2009 ◽  
Vol 77 (3-4) ◽  
pp. 328-337 ◽  
Author(s):  
Thomas Gentzis
2007 ◽  
Vol 44 (4) ◽  
pp. 445-457 ◽  
Author(s):  
Jan M Bednarski ◽  
I Rod Smith

Mapping the surficial geology of the Trutch map area (NTS 94G) provides new data on the timing of continental and montane glaciations along the Foothills of northeastern British Columbia. Striated surfaces on mountain crests were dated to the Late Wisconsinan substage by cosmogenic dating. The striations were produced by eastward-flowing ice emanating from the region of the Continental Divide. This ice was thick enough to cross the main ranges and overtop the Rocky Mountain Foothill summits at 2000 m above sea level (asl). It is argued here that such a flow, unhindered by topography, could only have been produced by the Cordilleran Ice Sheet and not by local cirque glaciation. During this time, the Cordilleran Ice Sheet dispersed limestone and schist erratics of western provenance onto the plains beyond the mountain front. Conversely, the Laurentide Ice Sheet did not reach its western limit in the Foothills until after Cordilleran ice retreated from the area. During its maximum, the Laurentide ice penetrated the mountain valleys up to 17 km west of the mountain front, and deposited crystalline erratics from the Canadian Shield as high as 1588 m asl along the Foothills. In some valleys a smaller montane advance followed the retreat of the Laurentide Ice Sheet.


1979 ◽  
Vol 16 (6) ◽  
pp. 1228-1241 ◽  
Author(s):  
Robert I. Thompson

The northern Canadian Rocky Mountains, as exemplified by the Halfway River map-area (94B) in British Columbia, consists of a rugged and mountainous structurally complex Foothills subprovince of large amplitude box and chevron-style folds in rocks of late Paleozoic and Mesozoic age, and a structurally diverse Rocky Mountain subprovince with open folds and apparently inconspicuous thrust faults in upper Precambrian to upper Paleozoic rocks; separating them is a narrow topographically subdued and heavily vegetated 'transition interval' comprising more penetratively folded and faulted shales and thin-bedded carbonate rocks of late Devonian and Mississippian age.Flat thrust faults, with displacements in the order of 10 km, which occur under the eastern margin of the Rocky Mountain subprovince (mountain front) extend across the 'transition interval' and beneath the western margin of the Foothills subprovince. These faults terminate within a décollement along the Devonian and Mississippian Besa River shale, as the displacement on them is transformed into disharmonic kink-type box and chevron folds in overlying units and into tectonic thickening within the Besa River shale. Because most of the major thrust faults along the Rocky Mountains are 'blind' and cannot be traced to surface exposures, one is left with the erroneous impression that very little lateral displacement (foreshortening) has occurred in the northern Canadian Rocky Mountains.The basic change from a well organized thrust-fault terrane in the southern Rockies to a more diverse fold terrane with few large mappable thrusts in the north is consistent with changes in the stratigraphic character of the rock prism that was deformed: the proportion of thick incompetent shale units increases northward, and major lateral carbonate to shale facies transitions traverse the eastern margin of the Rocky Mountain subprovince.Despite the differences in structural style from south to north, strain patterns within the northern Rocky Mountains are consistent with the lateral eastward movement of a detached prism of sedimentary rocks, and support the basic tenets of thin-skinned tectonics.


1984 ◽  
Vol 33 ◽  
pp. 57-69
Author(s):  
W. G. E. Caldwell ◽  
B. R. North

Marine Cretaceous rocks of Berriasian to Aptian age are restricted to northwestern Alberta and north­eastern British Columbia where many stage and substage boundaries may be drawn only tentatively on the basis of limited molluscan faunas. A complete marine Albian succession is similarly restricted, although the middle and upper divisions of the stage are much more widespread. The complete Albian succession of the Peace River district contains a refined and well-documented sequence of ammonite and foraminiferal zones and would be a most suitable continental standard. The Albian-Cenomanian (Lower-Upper Cretaceous) boundary has been reliably established in the continuous foraminifer- and mollusc-bearing sequences of the northwestern plains, but eastward it becomes enclosed in a hiatus. The same is true of successive stage boundaries from the Cenomanian­Turonian to the Santonian-Campanian. The bases for establishment of these boundaries, therefore, can be fully considered only on the western flank of the basin. The Campanian-Maastrichtian boundary may be precisely drawn in western Saskatchewan and traced westward to the Rocky Mountain front. Zones based on ammonites and inoceramid bivalves form· the cornerstone of the biostratigraphy and chronostratigraphy of the southern Interior Plains and hold the key to the stage boundaries. Zones based on assemblages of benthonic foraminifers, rarely of planktonic foraminifers, supplement the molluscan zones. The foraminiferal zones are less reliable and less useful, however, because some benthonic assemblages are weakly diachronous, most foraminiferal zones span several molluscan zones, and many stage boundaries fall within individual foraminifer zones.


1957 ◽  
Vol 89 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. D. Gregson

Tick paralysis continues to be one of the most baffling and fascinating tickborne diseases in Canada. It was first reported in this country by Todd in 1912. Since then about 250 human cases, including 28 deaths, have been recorded from British Columbia. Outbreaks in cattle have affected up to 400 animals at a time, with losses in a herd as high as 65 head. Although the disease is most common in the Pacific northwest, where it is caused by the Rocky Mountain wood tick, Dermacentor andersoni Stiles, it has lately been reported as far south as Florida and has been produced by Dermacentor variabilis Say, Amblyomma maculatum Koch, and A. americanum (L.) (Gregson, 1953). The symptoms include a gradual ascending symmetrical flaccid paralysis. Apparently only man, sheep, cattle, dogs, and buffalo (one known instance) are susceptible, but even these may not necessarily be paralysed.


2021 ◽  
pp. 146960532110198
Author(s):  
María Nieves Zedeño ◽  
Evelyn Pickering ◽  
François Lanoë

We highlight the significance of process, event, and context of human practice in Indigenous Creation traditions to integrate Blackfoot “Napi” origin stories with environmental, geological, and archaeological information pertaining to the peopling of the Northwestern Plains, where the northern Rocky Mountain Front may have played a prominent role. First, we discuss the potential and limitations of origin stories generally, and Napi stories specifically, for complementing the fragmentary records of early human presence in the Blackfoot homeland. Second, we demonstrate the intimate connection among processes, events, place-making practices, and stories. Last, we aim to expand multivocality in the interpretation of the deep past through an archaeological practice that considers Indigenous philosophies and stories to be as valid as non-Indigenous ones.


2006 ◽  
Vol 120 (2) ◽  
pp. 163
Author(s):  
George W. Douglas ◽  
Jenifer L. Penny ◽  
Ksenia Barton

In Canada, Dwarf Woolly-heads, Psilocarphus brevissimus var. brevissimus, is restricted to the Similkameen River valley, south of Princeton in southwestern British Columbia and the extreme southeast and southwest corners of Alberta and Saskatchewan, respectively. This paper deals with the three British Columbia populations which represent the northwestern limit of the species which ranges from south-central British Columbia, southward in the western United States to Montana, Idaho, Washington, Oregon, Nevada, Utah, Wyoming, California and Baja California, Mexico. In British Columbia, P. brevissimus is associated with calcareous vernal pools and ephemeral pond edges in large forest openings. This habitat is rare in the area the few existing populations could easily be extirpated or degraded through slight changes in groundwater levels, coalbed methane gas drilling, housing development or recreational vehicles.


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