Evidence for "Caribooan Orogeny" in the Southern Okanagan Region of British Columbia

1972 ◽  
Vol 9 (12) ◽  
pp. 1693-1702
Author(s):  
John V. Ross ◽  
William C. Barnes

A sequence of non-metamorphosed, little deformed, fossiliferous, sedimentary rocks, near Keremeos, southern British Columbia, unconformably overlies rocks having a history similar to that of the Vaseaux Formation, the most westerly exposed part of the Shuswap Complex of the southern Okanagan Valley. Fossils from the younger sequence have a late Mississippian – early Pennsylvanian age.This part of the southern Okanagan region has a deformational history that is pre-mid-Carboniferous and likely related to the Caribooan orogeny. This is in contrast to Late Paleozoic rocks at northern Okanagan localities and elsewhere in British Columbia that have under-gone strong deformation of probably Mesozoic age.

1968 ◽  
Vol 5 (4) ◽  
pp. 831-849 ◽  
Author(s):  
John V. Ross

Three major phases of folding affected rocks of Late Proterozoic and Early Paleozoic age and members long assigned to the Shuswap Complex of southeastern British Columbia. The main and first phase of folding produced a large recumbent anticline, having a northerly trend, overturned to the east, that contains an exotic wedge of granite-gneiss within its core. This gneiss was mechanically emplaced into the Late Proterozoic and Early Paleozoic sediments, and already had a metamorphic and deformational history prior to its emplacement. Its age is possible Hudsonian equivalent. Metamorphism during this recumbent phase of folding was greenschist facies.Phase 2 folding was accompanied by amphibolite facies metamorphism, and caused refolding of the earlier composite recumbent anticline into open folds along southeasterly axes.A third and final phase of folding, associated with waning metamorphism, gave rise to folds along southeasterly striking axial-planes that dip steeply to the northeast. Thus, phase three folds caused tightening-up of the previously formed folds.The absolute age of these deformations is not yet known, but the Shuswap Complex, at its eastern margin, is shown to include Paleozoic rocks and some older gneisses, possibly of Hudsonian age.


1984 ◽  
Vol 21 (3) ◽  
pp. 379-381
Author(s):  
Joanne Nelson ◽  
John G. Payne

New fossil, structural, and lithological evidence shows that the dominantly andesitic terrane near the junction of the Taku and Tulsequah rivers, northwestern British Columbia, is a proximal facies, roughly age equivalent to late Paleozoic tuffaceous and argillaceous sedimentary rocks exposed near Tatsamenie Lake, rather than of Late Triassic age as previously mapped. Fusulinids from the Tulsequah sequence are Middle Pennsylvanian, whereas the limestones at the top of the Paleozoic section near Tatsamenie Lake are of Permian age. The Tulsequah sequence hosts the Tulsequah Chief, Big Bull, and Ericksen – Ashby massive sulfide deposits, which arc associated with small bodies of rhyolite.


1989 ◽  
Vol 26 (7) ◽  
pp. 1503-1508
Author(s):  
John R. Montgomery ◽  
John V. Ross

The Quesnel Lake Gneiss is one of several large bodies of gneiss emplaced into the westernmost exposure of the Hadrynian to Paleozoic(?) metasedimentary rocks of the Snowshoe Group in the Omineca Belt, central British Columbia. The gneiss has a deformational history comparable to that of its enveloping rocks, and isotope studies indicate that its age of emplacement is Late Devonian to Early Mississippian and that its age of synkinematic metamorphism is mid-Jurassic. From petrochemical analyses and structural studies, we interpret the gneiss as being a late Paleozoic igneous intrusion into the probable western margin of the North American craton.


1977 ◽  
Vol 14 (8) ◽  
pp. 1832-1859 ◽  
Author(s):  
J. W. H. Monger

Volcanic and sedimentary successions of late Paleozoic and locally Mesozoic age in the Canadian Cordillera form six assemblages, based mainly on lithological association and similar stratigraphy. From east to west these assemblages are: (1) Eastern assemblage, located along the Omineca Crystalline Belt and consisting of Mississippian to Permian largely sedimentary rocks overlain by mainly Permian basic volcanics and ultramafics; (2) poorly known rocks in south-central British Columbia characterized by abundant volcaniclastics of Pennsylvanian and Permian ages; (3) Cache Creek – Bridge River assemblage of the Intermontane Bell, ranging from Lower Mississippian to Middle Jurassic and composed of chert, argillite, carbonate, basic volcanics, and ultramafics: (4) Stikine assemblage of northwestern and north-central British Columbia of Mississippian and Permian age, with basic to acidic volcanics, argillite, and carbonate; (5) Chilliwack Group on the west side of the Cascade Mountains, of Pennsylvanian and Permian age, with basic to acidic volcanics overlying a carbonate and clastic succession: and (6) Sicker–Skolai assemblage of Vancouver Island and the Saint Elias Mountains with basic to acidic volcanics overlain by sedimentary rocks. Coeval faunas in several of these assemblages differ. The assemblages may be largely unrelated to one another and came together in the Mesozoic, Their present distribution, with rocks typical of ocean basins (assemblages 1, 3) east of rocks that probably represent island arcs (assemblages, 2, 4, 5, 6) presents major problems. Two hypotheses attempt to explain this distribution. (1) The oceanic assemblages represent Paleozoic and early Mesozoic Pacific Ocean floor obducted over a broad arc terrane in the Jurassic, or (2) they are Paleozoic and early Mesozoic Pacific Ocean floor, trapped east of allochthonous arc terranes (assemblages 4, 5, 6) emplaced in the Mesozoic.


2001 ◽  
Vol 38 (1) ◽  
pp. 75-90 ◽  
Author(s):  
J Dostal ◽  
B N Church ◽  
T Hoy

The Paleozoic and early Mesozoic rocks of the Greenwood mining camp in southern British Columbia are a part of the Quesnel terrane in the eastern part of the Intermontane Belt of the Canadian Cordillera. Upper Paleozoic rocks include the Knob Hill Group composed of oceanic tholeiitic basalts (with (La/Yb)n [Formula: see text] 0.4–1.2), associated with deep ocean sedimentary rocks and serpentinites; the Attwood Group that comprises island-arc tholeiites (with (La/Yb)n [Formula: see text] 1–4 and positive εNd values), clastic sedimentary rocks and limestones; and a unit of oceanic gabbros with (La/Yb)n < 0.5. These lithologically defined units occur as tectonically emplaced slivers of oceanic crust probably produced during the closure of the Slide Mountain basin during the Permian. They are unconformably overlain by Middle Triassic calc-alkaline volcanic and sedimentary rocks of the Brooklyn Group. The Brooklyn Group volcanic rocks have characteristics of mature island-arc rocks, including (La/Yb)n [Formula: see text] 2.5–4.5 and positive εNd values. The Paleozoic rocks are crosscut by a 200 million years old granodioritic intrusion containing zircon with an Early Proterozoic inheritance age (~2.4 Ga). By inference, southern Quesnellia may have been well offshore from the ancestral North American margin in the Mississippian, in close proximity to the margin by the Middle Triassic, and contiguous with it by the Early Jurassic. It is suggested that the complex tectonic history of extension and contraction of the southern Canadian Cordillera during the post Middle Jurassic can be extended in south-central British Columbia as far back as the upper Paleozoic.


2020 ◽  
Vol 152 (4) ◽  
pp. 415-431
Author(s):  
Susanna Acheampong ◽  
Etienne Lord ◽  
D. Thomas Lowery

AbstractSpotted-wing drosophila, Drosophila suzukii, (Matsumura) (Diptera: Drosophilidae), has become a serious pest of soft fruit in the Okanagan Valley of British Columbia, Canada since its detection in 2009. The study was conducted to determine the distribution of D. suzukii and damage levels in grapes. Apple cider vinegar-baited traps placed in table and wine grape (Vitis vinifera Linnaeus; Vitaceae) vineyards during 2011–2013 demonstrated that D. suzukii was numerous in all sites, with earliest emergence and highest numbers recorded in 2013. Drosophila suzukii were reared from intact and damaged table grapes and damaged wine grapes collected from the field, but not from intact wine grapes. Drosophila suzukii were reared in low numbers in 2011 from intact fruit of 11 wine grape cultivars exposed artificially in the laboratory. Susceptibility of intact wine grapes under laboratory conditions in 2011 when sour rot was widespread might relate in part to undetected infections of berries due to weather conditions. Identification of Drosophila Fallén species revealed that D. suzukii comprised a small portion of the total. Our results demonstrate that healthy wine grapes in the Okanagan Valley of British Columbia are largely undamaged by D. suzukii, while certain table grape cultivars should be protected from attack.


1980 ◽  
Vol 17 (11) ◽  
pp. 1454-1461 ◽  
Author(s):  
Rolf W. Mathewes ◽  
John A. Westgate

Ash-grade Bridge River tephra, identified as such on the basis of shard habit, modal mineralogy, and composition of ilmenite, occurs in sedimentary cores from three lakes located to the south of the previously documented plume and necessitates a significant enlargement of the fallout area of that tephra in southwestern British Columbia.These new, more southerly occurrences are probably equivalent to the ~2350 year old Bridge River tephra, although it can be argued from the evidence at hand that the 14C dates and biotite-rich nature support relationship to a slightly earlier Bridge River event.Large differences exist in the 14C age of sediments immediately adjacent to the Bridge River tephra at these three lake sites; maximum ages of 3950 ± 170 years BP (GX-5549) and 3750 ± 210 years BP (I-10041) were obtained at Phair and Fishblue lakes, respectively, whereas the corresponding age at Horseshoe Lake is only 2685 ± 180 years BP (GX-5757). The two older dates are considered to be significantly affected by old carbon contamination for the bedrock locally consists of calcareous sedimentary rocks and the lacustrine sediments are very calcareous. The 14C date from Horseshoe Lake, which occurs in an area of igneous rocks, appears to be only slightly too old relative to the ~2350 year old Bridge River tephra.Well-dated tephra beds, therefore, can be very useful in assessing the magnitude of old carbon errors associated with radiocarbon dates based on limnic sediments. Calcareous gyttja deposits beneath Bridge River tephra within the study area exhibit old carbon errors of the order of 1350–1550 years.


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