Nina Creek Group and Lay Range Assemblage, north-central British Columbia: remnants of late Paleozoic oceanic and arc terranes

1997 ◽  
Vol 34 (6) ◽  
pp. 854-874 ◽  
Author(s):  
Filippo Ferri
Keyword(s):  
British Columbia ◽  
North America ◽  
Volcanic Rocks ◽  
Tholeiitic Basalt ◽  
Ocean Floor ◽  
North Central ◽  
Marginal Basin ◽  
The North ◽  
Lower Division ◽  
Ocean Ridge

In north-central British Columbia, a belt of upper Paleozoic volcanic and sedimentary rocks lies between Mesozoic arc rocks of Quesnellia and Ancestral North America. These rocks belong to two distinct terranes: the Nina Creek Group of the Slide Mountain terrane and the Lay Range Assemblage of the Quesnel terrane. The Nina Creek Group is composed of Mississippian to Late Permian argillite, chert, and mid-ocean-ridge tholeiitic basalt, formed in an ocean-floor setting. The sedimentary and volcanic rocks, the Mount Howell and Pillow Ridge successions, respectively, form discrete, generally coeval sequences interpreted as facies equivalents that have been interleaved by thrusting. The entire assemblage has been faulted against the Cassiar terrane of the North American miogeocline. West of the Nina Creek Group is the Lay Range Assemblage, correlated with the Harper Ranch subterrane of Quesnellia. It includes a lower division of Mississippian to Early Pennsylvanian sedimentary and volcanic rocks, some with continental affinity, and an upper division of Permian island-arc, basaltic tuffs and lavas containing detrital quartz and zircons of Proterozoic age. Tuffaceous horizons in the Nina Creek Group imply stratigraphic links to a volcanic-arc terrane, which is inferred to be the Lay Range Assemblage. Similarly, gritty horizons in the lower part of the Nina Creek Group suggest links to the paleocontinental margin to the east. It is assumed that the Lay Range Assemblage accumulated on a piece of continental crust that rifted away from ancestral North America in the Late Devonian to Early Mississippian by the westward migration of a west-facing arc. The back-arc extension produced the Slide Mountain marginal basin in which the Nina Creek Group was deposited. Arc volcanism in the Lay Range Assemblage and other members of the Harper Ranch subterrane was episodic rather than continuous, as was ocean-floor volcanism in the marginal basin. The basin probably grew to a width of hundreds rather than thousands of kilometres.

Development of late Paleozoic volcanic arcs in the Canadian Cordillera: an example from the Klinkit Group, northern British Columbia and southern Yukon

2003 ◽  
Vol 40 (7) ◽  
pp. 907-924 ◽  
Author(s):  
Renée-Luce Simard ◽  
Jaroslav Dostal ◽  
Charlie F Roots
Keyword(s):  
British Columbia ◽  
North America ◽  
Volcanic Rocks ◽  
Late Paleozoic ◽  
Canadian Cordillera ◽  
Alkali Basalts ◽  
The North ◽  
Pacific Margin ◽  
North American Craton ◽  
Arc Setting

The late Paleozoic volcanic rocks of the northern Canadian Cordillera lying between Ancestral North America to the east and the accreted terranes of the Omineca belt to the west record early arc and rift magmatism along the paleo-Pacific margin of the North American craton. The Mississippian to Permian volcano-sedimentary Klinkit Group extends discontinuously over 250 km in northern British Columbia and southern Yukon. The two stratotype areas are as follows: (1) in the Englishman Range, southern Yukon, the English Creek Limestone is conformably overlain by the volcano-sedimentary Mount McCleary Formation (Lower Clastic Member, Alkali-Basalt Member and Volcaniclastic Member), and (2) in the Stikine Ranges, northern British Columbia, the Screw Creek Limestone is conformably overlain by the volcano-sedimentary Butsih Formation (Volcaniclastic Member and Upper Clastic Member). The calc-alkali nature of the basaltic volcaniclastic members of the Klinkit Group indicates a volcanic-arc setting ((La/Yb)N = 2.77–4.73), with little involvement of the crust in their genesis (εNd = +6.7 to +7.4). Alkali basalts in the Mount McCleary Formation ((La/Yb)N = 12.5–17.8) suggest periodic intra-arc rifting events. Broadly coeval and compositionally similar volcano-sedimentary assemblages occur in the basement of the Mesozoic Quesnel arc, north-central British Columbia, and in the pericratonic Yukon–Tanana composite terrane, central Yukon, suggesting that they all represent pieces of a single long-lived, late Paleozoic arc system that was dismembered prior to its accretion onto Ancestral North America. Therefore, Yukon–Tanana terrane is possibly the equivalent to the basement of Quesnel terrane, and the northern Quesnel terrane has a pericratonic affinity.

THE EUROPEAN SKIPPER, THYMELICUS LINEOLA (LEPIDOPTERA: HESPERIIDAE), IN MANITOBA AND NORTHWESTERN ONTARIO

1981 ◽  
Vol 113 (12) ◽  
pp. 1123-1124 ◽  
Author(s):  
W. B. Preston ◽  
A. R. Westwood
Keyword(s):  
United States ◽  
British Columbia ◽  
Nova Scotia ◽  
North America ◽  
New Brunswick ◽  
Present Note ◽  
North Central ◽  
The North ◽  
Northwestern Ontario ◽  
Central United States

The spread of Thymelicus lineola (Ochsenheimer) in North America has been extensively documented (Rawson 1931; Clench 1956; Pengelly 1961; Arthur 1966; Burns 1966; McNeil et al. 1975; McNeil and Duchesne 1977). In Canada, T. lineola has been recorded from British Columbia, Ontario, Quebec, New Brunswick, Nova Scotia, Newfoundland, and now Manitoba (Gregory 1975; Jackson 1978). In the north central United States T. lineola has been recorded from St. Louis Co. and International Falls, Minnesota (Brewer 1977; Lundeen 1980). Pengelly (pers. comm.) observed T. lineola at Dryden, Ontario in 1972. McCabe and Post (1977) did not include this species in their list for North Dakota. The purpose of the present note is to report on the presence and collections of T. lineola in Manitoba and in northwestern Ontario.

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.

A New Gunnel, Pholis clemensi, from the Coast of Western North America

1964 ◽  
Vol 21 (5) ◽  
pp. 933-939 ◽  
Author(s):  
Richard H. Rosenblatt
Keyword(s):  
British Columbia ◽  
New Species ◽  
North America ◽  
North American ◽  
North American Species ◽  
Western North America ◽  
The North ◽  
The Family ◽  
Juan De Fuca ◽  
A New Species

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.

First mid-ocean ridge-type ophiolite from the Meso-Tethys suture zone in the north-central Tibetan plateau

2020 ◽  
Vol 132 (9-10) ◽  
pp. 2202-2220 ◽  
Author(s):  
Yue Tang ◽  
Qing-Guo Zhai ◽  
Sun-Lin Chung ◽  
Pei-Yuan Hu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Ocean Basin ◽  
Suture Zone ◽  
The Tibetan Plateau ◽  
Spreading Ridge ◽  
North Central ◽  
The North ◽  
Central Tibetan Plateau ◽  
Mid Ocean Ridge ◽  
Ocean Ridge

Abstract The Meso-Tethys was a late Paleozoic to Mesozoic ocean basin between the Cimmerian continent and Gondwana. Part of its relicts is exposed in the Bangong–Nujiang suture zone, in the north-central Tibetan Plateau, that played a key role in the evolution of the Tibetan plateau before the India-Asia collision. A Penrose-type ophiolitic sequence was newly discovered in the Ren Co area in the middle of the Bangong–Nujiang suture zone, which comprises serpentinized peridotites, layered and isotropic gabbros, sheeted dikes, pillow and massive basalts, and red cherts. Zircon U-Pb dating of gabbros and plagiogranites yielded 206Pb/238U ages of 169–147 Ma, constraining the timing of formation of the Ren Co ophiolite. The mafic rocks (i.e., basalt, diabase, and gabbro) in the ophiolite have uniform geochemical compositions, coupled with normal mid-ocean ridge basalt-type trace element patterns. Moreover, the samples have positive whole-rock εNd(t) [+9.2 to +8.3], zircon εHf(t) [+17 to +13], and mantle-like δ18O (5.8–4.3‰) values. These features suggest that the Ren Co ophiolite is typical of mid-ocean ridge-type ophiolite that is identified for the first time in the Bangong–Nujiang suture zone. We argue that the Ren Co ophiolite is the relic of a fast-spreading ridge that occurred in the main oceanic basin of the Bangong–Nujiang segment of Meso-Tethys. Here the Meso-Tethyan orogeny involves a continuous history of oceanic subduction, accretion, and continental assembly from the Early Jurassic to Early Cretaceous.

HEMITHEA AESTIVARIA IN BRITISH COLUMBIA: CHARACTERS OF A PALAEARCTIC GENUS AND SPECIES NOT PREVIOUSLY KNOWN FROM NORTH AMERICA (LEPIDOPTERA: GEOMETRIDAE: GEOMETRINAE)

1979 ◽  
Vol 111 (10) ◽  
pp. 1121-1126 ◽  
Author(s):  
K.B. Bolte ◽  
Eugene Munroe
Keyword(s):  
British Columbia ◽  
North America ◽  
North American ◽  
Palaearctic Species ◽  
The North

AbstractThe palaearctic species Hemithea aestivaria (Hübner) (Lepidoptera: Geometridae: Geometrinae: Hemitheini), newly reported from British Columbia, is described, discussed and illustrated. The genus and species are new to the North American fauna.

Early Eocene (Ypresian) birds from the Okanagan Highlands, British Columbia (Canada) and Washington State (USA)

2019 ◽  
Vol 56 (8) ◽  
pp. 803-813
Author(s):  
Gerald Mayr ◽  
S. Bruce Archibald ◽  
Gary W. Kaiser ◽  
Rolf W. Mathewes
Keyword(s):  
British Columbia ◽  
North America ◽  
Fossil Record ◽  
Washington State ◽  
Fossil Birds ◽  
Early Eocene ◽  
Western North America ◽  
Postcranial Skeleton ◽  
The North ◽  
Okanagan Highlands

We survey the known avian fossils from Ypresian (early Eocene) fossil sites of the North American Okanagan Highlands, mainly in British Columbia (Canada). All specimens represent taxa that were previously unknown from the Eocene of far-western North America. Wings from the McAbee site are tentatively referred to the Gaviiformes and would constitute the earliest fossil record of this group of birds. A postcranial skeleton from Driftwood Canyon is tentatively assigned to the Songziidae, a taxon originally established for fossils from the Ypresian of China. Two skeletons from Driftwood Canyon and the McAbee site are tentatively referred to Coliiformes and Zygodactylidae, respectively, whereas three further fossils from McAbee, Blakeburn, and Republic (Washington, USA) are too poorly preserved for even a tentative assignment. The specimens from the Okanagan Highlands inhabited relatively high paleoaltitudes with microthermal climates (except Quilchena: lower mesothermal) and mild winters, whereas most other Ypresian fossil birds are from much warmer lowland paleoenvironments with upper mesothermal to megathermal climates. The putative occurrence of a gaviiform bird is particularly noteworthy because diving birds are unknown from other lacustrine Ypresian fossil sites of the Northern Hemisphere. The bones of the putative zygodactylid show a sulphurous colouration, and we hypothesize that this highly unusual preservation may be due to the metabolic activity of sulphide-oxidizing bacteria.

New occurrences of the Pennsylvanian index ammonoidDunbaritesfrom the North American midcontinent

2009 ◽  
Vol 83 (3) ◽  
pp. 405-413 ◽  
Author(s):  
David M. Work ◽  
Royal H. Mapes
Keyword(s):  
North America ◽  
Type Species ◽  
Additional Species ◽  
North Central ◽  
The North ◽  
South Central ◽  
West Texas ◽  
Kasimovian Stage ◽  
New Occurrences ◽  
Stratigraphic Range

Ten newly recoveredDunbaritesspecimens significantly extend the known stratigraphic range ofDunbarites.These include the first documented Midcontinent Basin records of the Missourian type speciesDunbarites rectilateralis(Miller, 1930) from north-central Oklahoma. Additional species ofDunbaritesfrom south-central Oklahoma and north-central and West Texas are described asDunbarites wewokensisn. sp. andDunbarites boardmanin. sp. AlthoughDunbaritesis an extremely rare component (~0.025 percent) of Middle and Upper Pennsylvanian ammonoid assemblages, Ruzhencev and Bogoslovskaya (1971, 1978) suggested thatDunbaritesandParashumarditesRuzhencev, 1939 be used as genozone markers for the Kasimovian [Zhigulevian] Stage (Missourian in North America). As demonstrated by this report, the range ofDunbaritesis not confined to the Kasimovian, thereby precluding its use as a Kasimovian Stage indicator.

Early Proterozoic (1.88–1.87 Ga) tholeiitic magmatism in the New Québec orogen

1993 ◽  
Vol 30 (7) ◽  
pp. 1505-1520 ◽  
Author(s):  
Thomas Skulski ◽  
Robert P. Wares ◽  
Alan D. Smith
Keyword(s):  
Volcanic Rocks ◽  
Crustal Contamination ◽  
Passive Margin ◽  
Magma Chambers ◽  
Sedimentary Sequences ◽  
The North ◽  
Marine Sedimentation ◽  
Lithospheric Extension ◽  
Felsic Volcanic ◽  
Ocean Ridge

The New Québec orogen contains two volcano-sedimentary sequences bounded by unconformities. Each sequence records a change from continental sedimentation and alkaline volcanism to marine sedimentation and tholeiitic volcanism. The first sequence records 2.17 Ga rifting and the development, by 2.14 Ga, of a passive margin along the eastern part of the Superior craton. The second sequence developed between 1.88 and 1.87 Ga in pull-apart basins that reflect precollisional dextral transtension along the continental margin. Second-sequence magmatism comprises (i) carbonatitic and lamprophyric intrusions and mildly alkaline mafic to felsic volcanic rocks; (ii) widespread intrusion of tholeiitic gabbro sills, and submarine extrusion of plagioclase glomeroporphyritic basalts and younger aphyric basalts and picrites; and (iii) late-stage, mafic to felsic volcanism and intrusion of carbonatites. Crustal thinning allowed primitive tholeiitic magmas to equilibrate at progressively lower pressures before more buoyant derivative liquids could erupt. Early primitive melts were trapped at the base of the crust and crystallized olivine and orthopyroxene with minor crustal contamination. Derivative melts, similar to transitional mid-ocean-ridge basalts, migrated upward into mid-crustal magma chambers where they became saturated in calcic plagioclase. Subsequent tapping of these magma chambers allowed plagioclase ultraphyric magmas to intrude the sedimentary pile and erupt on the sea floor. Prolonged lithospheric extension resulted in more voluminous mantle melting and eruption of picrites and basalts in the south. Primitive magmas in the north were trapped beneath thicker crust and crystallized wehrlite cumulates. Resulting basaltic melts intruded the volcano-sedimentary pile, or erupted as aphyric basalts.

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