40Ar/39Ar dating of phyllonite in the Western Rocky Mountains and Southern Rocky Mountain Trench unravel kinematic links between the Omineca and Foreland Belts of the Southern Canadian Cordillera

2021 ◽  
Author(s):  
Dinu Pana
1986 ◽  
Vol 23 (8) ◽  
pp. 1047-1061 ◽  
Author(s):  
L. C. Struik

The Cariboo gold belt of east-central British Columbia is divided into four fault-bounded sequences of distinct stratigraphy. They are, from east to west, the Cariboo (continental-shelf sediments), Barkerville (continental-shelf sediments and intercalated volcanics), Slide Mountain (rift-related submarine pillow basalt, chert, and diorite) and Quesnel (island-arc sediments and subaqueous volcanics) terranes. Each is separated from others by thrust faults. Grit, phyllite, limestone, and volcanics of the Barkerville terrane may be correlative with the Eagle Bay Formation near Adams Lake and the Lardeau Group near Kootenay Lake. Barkerville terrane may be part of a more regional rock package, Selkirk terrane, which is defined to include Kootenay terrane, Badshot Formation, and Horsethief Creek and Hamill groups. Selkirk terrane is (i) separated everywhere by a low-angle fault from the overlying age-equivalent but stratigraphically and structurally different Cariboo terrane and (ii) separated by a system of faults in the general location of the Southern Rocky Mountain Trench from the age-equivalent but stratigraphically and structurally different North American terrane of the Rocky Mountains.


Praxis ◽  
2005 ◽  
Vol 94 (47) ◽  
pp. 1869-1870
Author(s):  
Balestra ◽  
Nüesch

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.


Geology ◽  
2021 ◽  
Author(s):  
Jason W. Ricketts ◽  
Jacoup Roiz ◽  
Karl E. Karlstrom ◽  
Matthew T. Heizler ◽  
William R. Guenthner ◽  
...  

The Great Unconformity of the Rocky Mountain region (western North America), where Precambrian crystalline basement is nonconformably overlain by Phanerozoic strata, represents the removal of as much as 1.5 b.y. of rock record during 10-km-scale basement exhumation. We evaluate the timing of exhumation of basement rocks at five locations by combining geologic data with multiple thermochronometers. 40Ar/39Ar K-feldspar multi-diffusion domain (MDD) modeling indicates regional multi-stage basement cooling from 275 to 150 °C occurred at 1250–1100 Ma and/or 1000–700 Ma. Zircon (U-Th)/He (ZHe) dates from the Rocky Mountains range from 20 to 864 Ma, and independent forward modeling of ZHe data is also most consistent with multi-stage cooling. ZHe inverse models at five locations, combined with K-feldspar MDD and sample-specific geochronologic and/or thermochronologic constraints, document multiple pulses of basement cooling from 250 °C to surface temperatures with a major regional basement exhumation event 1300–900 Ma, limited cooling in some samples during the 770–570 Ma breakup of Rodinia and/or the 717–635 Ma snowball Earth, and ca. 300 Ma Ancestral Rocky Mountains cooling. These data argue for a tectonic control on basement exhumation leading up to formation of the Precambrian-Cambrian Great Unconformity and document the formation of composite erosional surfaces developed by faulting and differential uplift.


2021 ◽  
Author(s):  
A.K. Gilmer ◽  
et al.

<div>Table S1: Whole-rock compositions of analyzed samples. Table S2: Major and trace element geochemistry of feldspar. Table S3: Major and trace element geochemistry of pyroxene. Table S4: Major and trace element geochemistry of biotite. Table S5: Major and trace element geochemistry of amphibole. Table S6: Zircon geochronology and trace element geochemistry. Table S7: Lutetium and hafnium isotopic compositions of zircon. Table S8: Amphibole-plagioclase thermometry. Table S9: Sample locations and lithologies.<br></div>


2019 ◽  
Vol 20 (11) ◽  
pp. 5225-5250
Author(s):  
F. Tomek ◽  
A .K. Gilmer ◽  
M. S. Petronis ◽  
P. W. Lipman ◽  
M. S. Foucher

2018 ◽  
Vol 131 (4) ◽  
pp. 303-311
Author(s):  
Lisa M. Baril ◽  
David B. Haines ◽  
Lauren E. Walker ◽  
Douglas W. Smith

Raptors are wide-ranging, vagile avian predators whose populations can be difficult and costly to monitor on their breeding or winter range. However, monitoring raptors during their annual northbound or southbound migration is a cost-effective and efficient alternative to time-intensive, single-species breeding surveys. In 2010, we observed numerous Swainson’s Hawks (Buteo swainsoni) and Red-tailed Hawks (Buteo jamaicensis) migrating through the Hayden Valley in central Yellowstone National Park, prompting an investigation into raptor migration patterns in the park. Our objectives were to monitor annual autumn raptor migration in Hayden Valley from 2011 to 2015 and to determine the relative role of this undocumented migration site by comparing our observations to simultaneously collected migration data from three other sites in the Rocky Mountain Flyway. From 2011 to 2015, we observed 6441 raptors of 17 species across 170 d and 907 h of observation. Red-tailed Hawks, Swainson’s Hawks, and Golden Eagles (Aquila chrysaetos) accounted for 51% of the total individuals observed over five years. Overall counts from Hayden Valley were comparable to counts from the three migration sites in the Rocky Mountains, although abundance of individual species varied by site. Data from this study suggest that Hayden Valley may serve as a stopover site for migrating raptors and presents an opportunity for future research. By improving our understanding of where raptors migrate and the characteristics of stopover areas in the Rocky Mountains, land managers may develop effective strategies for protecting raptor populations and habitat from threats including development and climate change.


1964 ◽  
Vol 1 (3) ◽  
pp. 184-205 ◽  
Author(s):  
C. H. Crickmay

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.


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