Preliminary paleomagnetic results from the Permian Asitka Group, British Columbia

1987 ◽  
Vol 24 (7) ◽  
pp. 1490-1497 ◽  
Author(s):  
E. Irving ◽  
J. W. H. Monger

Tuffs, rhyolites, and basalts collected at seven sites (25 samples) in the Early Permian Asitka Group of Stikinia have similar paleomagnetic inclinations, and corresponding paleolatitudes of 23 ± 6, 21 ± 4, and 23 ± 5 °respectively. Both polarities occur, so the paleolatitudes could be either north or south of the paleoequator, although the polarity bias favours the former option. The paleolatitude expected for the sampling region is 27 ± 4°N. Adopting the paleomagnetically more probable northern option, the mean displacement relative to the North American craton is 5 ± 6°, indicating that Stikinia was in much the same latitudinal position relative to the craton during the Early Permian as it is at present, although possibly somewhat to the south. The declinations are in poor agreement, indicating that relative rotations occurred in this faulted terrane.

1981 ◽  
Vol 18 (12) ◽  
pp. 1767-1775 ◽  
Author(s):  
L. C. Struik

Three tectonostratigraphic successions are established from remapping of the area near Barkerville and Cariboo River. The first, of Late Proterozoic to Cambrian sediments, was deposited on the shallow to moderately deep platformal shelf west of and derived from the exposed North American craton. The second is an unconformably overlying Ordovician to Permian sequence of sedimentary and volcanic rocks representing a basinal environment with periodic highs. These packages of sediments were deposited on the North American craton and its western transitional extensions. The third succession, composed of oceanic chert and basalt of the Permo-Pennsylvanian Antler Formation, was thrust eastward over the other two during the early Mesozoic. The three successions were folded, faulted, and metamorphosed during the mid-Mesozoic Columbian Orogeny. The Devono-Mississippian Cariboo Orogeny, which was thought to have affected all of the first sequence and part of the second, could not be documented in its type locality. The geology of the Barkerville – Cariboo River area has many similarities with that of Selwyn Basin and Cassiar platform of northern British Columbia and Yukon.


2011 ◽  
Vol 85 (1) ◽  
pp. 29-31
Author(s):  
George D. Stanley ◽  
John-Paul Zonneveld

Cassianastraea is an enigmatic colonial Triassic cnidarian first described as a coral but subsequently referred to the Hydrozoa. We report here the first occurrence in Canada of fossils we designate as Cassianastraea sp. from the Williston Lake region of British Columbia. The specimens come from older collections of the Geological Survey of Canada, collected in Upper Triassic (Carnian) strata assigned to either the Ludington or Baldonnel Formations. While well known in reef associations of the former Tethys region, Cassianiastraea is relatively rare in North America. The Carnian Baldonnel Formation contains the earliest coral reefs from the North American craton and we suspect that Cassianastraea sp. also came from this reef association.


2007 ◽  
Vol 243 (3-4) ◽  
pp. 421-450 ◽  
Author(s):  
John-Paul Zonneveld ◽  
Charles M. Henderson ◽  
George D. Stanley ◽  
Michael J. Orchard ◽  
Murray K. Gingras

1993 ◽  
Vol 30 (4) ◽  
pp. 776-786
Author(s):  
G. Murthy ◽  
R. Pätzold

The Pridolian Clam Bank Formation around Lourdes Cove on the Port au Port Peninsula, western Newfoundland, underwent deformation during the Acadian orogeny. As a result, some of the beds were overturned, but the stratification planes can be accurately determined everywhere. Paleomagnetic studies of the Clam Bank Formation have yielded three well-defined components of magnetization, all acquired subsequent to the deformation event: component A with D = 337.3°, I = −28.3°, (N = 16 sites, k = 25.3, α95 = 7.5°), with a corresponding paleopole at 23.2°N, 145.0°E (dp, dm = 4.5°, 8.2°); component B with D = 172.9°, I = 5.7° (N = 35 specimens, k = 10.2, α95 = 6.4°), with a corresponding paleopole at 38.2°N, 130.1°E (dp, dm = 3.2°, 6.4°); component C with D = 350.4°, I = 69.8° (N = 33 specimens, k = 8.9, α95 = 8.9°). A pre-Mesozoic origin of the A and B components is indicated by the presence of normal and reversed components in specific sites; by the lack of correspondence between the A and B paleopoles and the Mesozoic and later pole positions from the Appalachians and the North American craton; and by agreement with Paleozoic poles from the region. The A component was probably acquired immediately after deformation during the Acadian orogeny. The B component is probably a chemical remanence that was acquired during Permo-Carboniferous (Kiaman) time. The C component is of recent origin, probably acquired in the present Earth's field. Paleomagnetic data from western Newfoundland are used in a localized setting to construct a paleopole sequence and to estimate paleolatitudes for western Newfoundland during the Paleozoic. Keeping in mind the paucity of data for Siluro-Devonian age from this region, western Newfoundland seems to have been at its southernmost position at the end of the Ordovician and to have occupied equatorial latitudes during the Permo-Carboniferous. The paleolatitude trend suggests that this block, which is part of the North American craton, moved in a southerly direction during the early Paleozoic and in a northerly direction during the middle and late Paleozoic.


2016 ◽  
Vol 46 (3) ◽  
pp. 367-378 ◽  
Author(s):  
Jason Brown ◽  
Henry Davis ◽  
Michael Schwan ◽  
Barbara Sennott

Gitksan (git) is an Interior Tsimshianic language spoken in northwestern British Columbia, Canada. It is closely related to Nisga'a, and more distantly related to Coast Tsimshian and Southern Tsimshian. The specific dialect of Gitksan presented here is what can be called Eastern Gitksan, spoken in the villages of Kispiox (Ansbayaxw), Glen Vowell (Sigit'ox), and Hazelton (Git-an'maaxs), which contrasts with the Western dialects, spoken in the villages of Kitwanga (Gitwingax), Gitanyow (Git-anyaaw), and Kitseguecla (Gijigyukwhla). The primary phonological differences between the dialects are a lexical shift in vowels and the presence of stop lenition in the Eastern dialects. While there exists a dialect continuum, the primary cultural and political distinction drawn is between Eastern and Western Gitksan. For reference, Gitksan is bordered on the west by Nisga'a, in the south by Coast Tsimshian and Witsuwit'en, in the east by Dakelh and Sekani, and in the north by Tahltan (the latter four of these being Athabaskan languages).


1906 ◽  
Vol 3 (7) ◽  
pp. 301-310 ◽  
Author(s):  
F. R. Cowper Reed

A Small collection of fossils from the Bokkeveld Beds has recently been sent to me for identification by the South African Museum, and some of them have been generously presented to the Sedgwick Museum. Amongst this material it is interesting to find some genera not previously recorded from the Cape and some new species. The majority of the specimens are in the condition of internal casts, and hence present especial difficulties in their determination, so that in a few cases some uncertainty must remain as to the generic position of the fossils. However, I am able to record for the first time from these beds the occurrence of the well-known lamellibranchiate genus Buchiola, and of a shell which may be identified with Nyussa arguta, Hall, of the North American Devonian. The genus Buchiola occurs in argillaceous nodules from the Zwartberg Pass crowded with individuals of the species which I have named B. subpalmata and with a few examples of an undetermined species. No other associated fossils can be recognised in these nodules, but I am informed that an abundant fauna is found in the beds at this locality.


1989 ◽  
Vol 26 (2) ◽  
pp. 296-304 ◽  
Author(s):  
Julie E. Gales ◽  
Ben A. van der Pluijm ◽  
Rob Van der Voo

Paleomagnetic sampling of the Lawrenceton Formation of the Silurian Botwood Group in northeastern Newfoundland was combined with detailed structural mapping of the area in order to determine the deformation history and make adequate structural corrections to the paleomagnetic data.Structural analysis indicates that the Lawrenceton Formation experienced at least two folding events: (i) a regional northeast–southwest-trending, Siluro-Devonian folding episode that produced a well-developed axial-plane cleavage; and (ii) an episode of local north-trending folding. Bedding – regional cleavage relationships indicate that the latter event is older than the regional folding.Thermal demagnetization of the Lawrenceton Formation yielded univectorial southerly and shallow directions (in situ). A fold test on an early mesoscale fold indicates that the magnetization of the Botwood postdates this folding event. However, our results, combined with an earlier paleomagnetic study of nearby Lawrenceton Formation rocks, demonstrate that the magnetization predates the regional folding. Therefore, we conclude that the magnetization occurred subsequent to the local folding but prior to the period of regional folding.While a tectonic origin for local folding cannot be entirely excluded, the subaerial nature of these volcanics, the isolated occurrence of these folds, and the absence of similar north-trending folds in other areas of eastern Notre Dame Bay suggest a syndepositional origin. Consequently, the magnetization may be nearly primary. Our study yields a characteristic direction of D = 175°, I = +43°, with a paleopole (16°N, 131 °E) that plots near the mid-Silurian track of the North American apparent polar wander path. This result is consistent with an early origin for the magnetization and supports the notion that the Central Mobile Belt of Newfoundland was adjacent to the North American craton, in its present-day position, since the Silurian.


1964 ◽  
Vol 21 (5) ◽  
pp. 933-939 ◽  
Author(s):  
Richard H. Rosenblatt

A new species, Pholis clemensi, referred to the family Pholidae, is named and described from 12 specimens taken in southern British Columbia waters and the Strait of Juan de Fuca. Pholis clemensi is compared with other members of the genus, and a key is given to the North American species.


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