scholarly journals Late triassic and jurassic magmatism along the Stikine Arch and the geology of the Stikine batholith, north-central British Columbia

1984 ◽  
Author(s):  
R G Anderson
Keyword(s):  
British Columbia ◽  
Late Triassic ◽  
North Central

Revised stratigraphy of the Takla Group, north-central British Columbia

1977 ◽  
Vol 14 (2) ◽  
pp. 318-326 ◽  
Author(s):  
J. W. H. Monger ◽  
B. N. Church
Keyword(s):  
British Columbia ◽  
Sedimentary Rocks ◽  
Lower Jurassic ◽  
Upper Triassic ◽  
Late Triassic ◽  
North Central ◽  
Volcaniclastic Rocks ◽  
Jurassic Rocks

The Takla Group of north-central British Columbia as originally defined contained volcanic and sedimentary rocks of Late Triassic and Jurassic ages. As redefined herein, it consists of three formations in the McConnell Creek map-area. Lowest is the Dewar Formation, composed of argillite and volcanic sandstone that is largely the distal equivalent of basic flows and coarse volcaniclastic rocks of the Savage Mountain Formation. These formations are overlain by the volcaniclastic, basic to intermediate Moosevale Formation. These rocks are Upper Triassic (upper Karnian and lower Norian). They are unconformably overlain by Lower Jurassic rocks of the Hazelton Group.

Late Paleozoic and Mesozoic terrane interactions in north-central British Columbia

1991 ◽  
Vol 28 (6) ◽  
pp. 947-957 ◽  
Author(s):  
Hubert Gabrielse
Keyword(s):  
British Columbia ◽  
North America ◽  
Middle Jurassic ◽  
Subsequent Development ◽  
Structural Data ◽  
Strike Slip ◽  
Granitic Rocks ◽  
Late Triassic ◽  
North Central ◽  
Dextral Strike Slip

Five clearly defined terranes, comprising from northeast to southwest, Ancestral North America, Slide Mountain, Quesnellia, Cache Creek, and Stikinia, are the dominant tectonic elements of north-central British Columbia. Stratigraphic, sedimentological, plutonic, metamorphic, and structural data show that the Slide Mountain Terrane evolved as a subduction, accretion, and island-arc complex during Permian time. Sedimentological data hint at the demise of the Slide Mountain and Cache Creek oceanic environments in the Permian or Early Triassic and Late Triassic, respectively. Subduction led to the development of volcanic–plutonic island arcs on Stikinia, Quesnellia, and locally on the Cache Creek Terrane in Late Triassic to Middle Jurassic time. Marked inter- and intra-terrane contraction in the Middle Jurassic resulted in the south westward thrusting of the Cache Creek Terrane onto Stikinia, the subsequent development of the Bowser Basin on Stikinia, and possible coeval culmination of the emplacement of Quesnellia and the Slide Mountain Terrane onto Ancestral North America. Deformation, metamorphism, and plutonism along the western margin of Ancestral North America closely followed these events. Contraction was succeeded by a dextral strike-slip regime during the mid-Cretaceous accompanied by the intrusion of voluminous potassic, silica-rich granitic rocks in Ancestral North America. The emplacement of Early to mid-Cretaceous plutons postdated the development of broad, open, regional anticlinoria and synclinoria, perhaps during Early Cretaceous time. The plutonic episode coincided approximately with initiation of the Sustut Basin. Dextral strike-slip faulting further disrupted Ancestral North America until post-Eocene time.

Cretaceous remagnetization in the Sylvester Allochthon: limits to post-105 Ma northward displacement of north-central British Columbia

1988 ◽  
Vol 25 (8) ◽  
pp. 1316-1322 ◽  
Author(s):  
R. F. Butler ◽  
T. A. Harms ◽  
H. Gabrielse
Keyword(s):  
British Columbia ◽  
Confidence Level ◽  
Remanent Magnetization ◽  
Rocky Mountain ◽  
Natural Remanent Magnetization ◽  
Late Triassic ◽  
Geological Evidence ◽  
North Central ◽  
Thermal Demagnetization ◽  
Pole Location

The Sylvester Allochthon of the Slide Mountain Terrane in northern British Columbia is a structurally interleaved assemblage of ocean-floor lithologies ranging in age from Late Devonian to Late Triassic. It is the most inboard of oceanic suspect terranes and rests as a vast klippe on miogeoclinal strata of the Cassiar Terrane. The Sylvester Allochton and the Cassiar Terrane lie west of the Northern Rocky Mountain Trench Fault. Both the Sylvester Allochthon and the Cassiar Terrane are intruded by mid-Cretaceous (105 Ma) granite of the Cassiar Batholith. Six oriented cores were collected at each of 12 sites in Guadalupian Parafusulina-bearing limestone of the Sylvester Allochthon at a location 4 km from the batholith. Isothermal remanent magnetization (IRM) acquisition and subsequent thermal demagnetization indicate that pyrrhotite is the dominant ferrimagnetic mineral. Least-squares line fitting to four thermal demagnetization steps between 150 and 310 °C was used to determine the characteristic natural remanent magnetization (NRM) directions that fail the fold test at the 99.5% confidence level. We interpret these observations as indicating that the NRM is a thermoremanent or thermochemical remanent magnetism associated with intrusion of the Cassiar Batholith. The resulting paleomagnetic pole location is latitude = 75.7°N, longitude = 171.7°E, α95 = 8.5°. When compared with the mid-Cretaceous pole for cratonic North America, a small but significant clockwise rotation (R ± ΔR = 23.9 ± 18.1 °) is evident, but poleward translation (p ± Δp = 5.3 ± 9.2°) is not significant at the 95% confidence level. The paleomagnetic results are consistent with geological evidence for moderate (700 km) northward transport of the Cassiar Terrane (along with the previously emplaced overlying Sylvester Allochthon) during mid-Cretaceous to Tertiary dextral transcurrent faulting.

Using perceptual maps to communicate concepts of Sustainable Forest Management – Collaborative research with the Office of the Wet'suwet'en Nation in British Columbia

2005 ◽  
Vol 81 (3) ◽  
pp. 381-386
Author(s):  
S. Denise Allen
Keyword(s):  
British Columbia ◽  
Forest Management ◽  
Collaborative Research ◽  
Sustainable Forest Management ◽  
Software Tool ◽  
Decision Makers ◽  
North Central ◽  
Criteria And Indicators ◽  
Perceptual Maps ◽  
Forest Resources Management

This article discusses collaborative research with the Office of the Wet'suwet'en Nation on their traditional territories in north-central British Columbia, Canada, a forest-dependent region where contemporary and traditional forest resources management regimes overlap. In-depth personal interviews with the hereditary chiefs and concept mapping were used to identify social-ecological linkages in Wet'suwet'en culture to inform the development of culturally sensitive social criteria and indicators of sustainable forest management (SFM) in this region. The preliminary results demonstrate how the CatPac II software tool can be applied to identify key component concepts and linkages in local definitions of SFM, and translate large volumes of (oral) qualitative data into manageable information resources for forest managers and decision-makers. Key words: social criteria and indicators, sustainable forest management, qualitative research, Wet'suwet'en

A Lower Jurassic heteroporid bryozoan and associated biota, Turnagain Lake, British Columbia

1981 ◽  
Vol 18 (3) ◽  
pp. 457-468 ◽  
Author(s):  
C. M. Henderson ◽  
D. G. Perry
Keyword(s):  
British Columbia ◽  
North America ◽  
Green Alga ◽  
Marine Environment ◽  
High Energy ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Associated Fauna ◽  
North Central ◽  
Commensal Relationship

Late Early Jurassic heteroporid bryozoa occur in arenaceous carbonates near Turnagain Lake, north-central British Columbia. The occurrence of Heteropora tipperi n. sp. marks the first documentation of Early Jurassic cyclostome bryozoa in North America. The associated fauna, comprising the ammonite Harpoceras, the foraminifer Reinholdella, and the pelecypod Weyla, establish the age as Early Toarcian. Other associated biota include an endolithic green alga(e), which is demonstrated to have a commensal relationship with H. tipperi n. sp. Sedimentologic and biotic data from the host strata point to a shallow, temperate, high-energy, normal marine environment.

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