Mesozoic–Cenozoic paleomagnetism of the Intermontane and Yukon–Tanana terranes, Canadian Cordillera

2005 ◽  
Vol 42 (6) ◽  
pp. 1163-1185 ◽  
Author(s):  
D TA Symons ◽  
M J Harris ◽  
P JA McCausland ◽  
W H Blackburn ◽  
C JR Hart
Keyword(s):  
Early Jurassic ◽  
Late Triassic ◽  
Canadian Cordillera ◽  
Geological Evidence ◽  
Polar Wander ◽  
The North ◽  
Apparent Polar Wander Path ◽  
The Pacific ◽  
North American Craton ◽  
Made In

Lithoprobe Slave – Northern Cordillera Lithospheric Evolution (SNORCLE) transect support enabled 24 paleomagnetic collections (536 sites, 6547 specimens) to be made in the northern Cordillera. Paleopoles from 16 studies are integrated with other published paleopoles to present a tectonic synthesis for the Intermontane Belt (IMB) and Yukon–Tanana (YT) terranes since 215 Ma. It shows that the YT terrane has been parautochthonous with the North American craton at least since the Early Jurassic. Since 54 Ma the IMB terranes have rotated steadily clockwise at 0.29° ± 0.11°/Ma on top of the YT terrane and craton or by 16° ± 6° clockwise. Between 102 ± 14 and 54 Ma, the IMB terranes rotated another 35° ± 14° clockwise, probably during Paleocene collision with the craton, and were translated 8.3° ± 7.0° (2σ) (915 ± 775 km) northward, probably during the Late Cretaceous on the Kula plate. The 915 km estimate is much less than most paleomagnetic estimates for "Baja BC" but agrees with the geological evidence. These post-Jurassic estimates are used to reconstruct the position of the Late Triassic – Jurassic cratonic apparent polar wander path for the IMB. The resulting IMB path is found to be concordant with the Cache Creek and Quesnellia terrane poles, indicating that these terranes were together and close to the craton in the Early Jurassic. These results place the IMB terranes close to the Pacific coastline of the northern USA and southern Canada but rotated 35° ± 14° counterclockwise, in the Jurassic and Early Cretaceous.

Paleomagnetism of the Lawrenceton Formation volcanic rocks, Silurian Botwood Group, Change Islands, Newfoundland

1989 ◽  
Vol 26 (2) ◽  
pp. 296-304 ◽  
Author(s):  
Julie E. Gales ◽  
Ben A. van der Pluijm ◽  
Rob Van der Voo
Keyword(s):  
North American ◽  
Volcanic Rocks ◽  
Mobile Belt ◽  
Structural Mapping ◽  
Polar Wander ◽  
The North ◽  
Apparent Polar Wander Path ◽  
Paleomagnetic Study ◽  
North American Craton

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.

Biostratigraphic and biogeographic constraints on the Carboniferous to Jurassic Cache Creek Terrane in central British Columbia

2001 ◽  
Vol 38 (4) ◽  
pp. 551-578 ◽  
Author(s):  
M J Orchard ◽  
F Cordey ◽  
L Rui ◽  
E W Bamber ◽  
B Mamet ◽  
...  
Keyword(s):  
North American ◽  
Early Jurassic ◽  
Late Carboniferous ◽  
Middle Permian ◽  
Late Triassic ◽  
Fine Grained ◽  
North American Continent ◽  
The North ◽  
Carbonate Buildups ◽  
North American Craton

Conodonts, radiolarians, foraminiferids, and corals provide constraints on the geology and tectonics of the Nechako region. They also support the notion that the Cache Creek Terrane is allochthonous with respect to the North American craton. The 177 conodont collections, assigned to 20 faunas, range in age from Bashkirian (Late Carboniferous) to Norian (Late Triassic); 70 radiolarian collections representing 12 zones range from Gzhelian (Late Carboniferous) to Toarcian (Early Jurassic); 335 collections assigned to 11 fusulinacean assemblages (with associated foram-algal associations) range from Bashkirian to Wordian (Middle Permian); and two coral faunas are of Bashkirian and Wordian age. The fossils document a long but sporadic history of sedimentary events within the Cache Creek Complex that included two major carbonate buildups in the Late Carboniferous (Pope limestone) and Middle Permian (Copley limestone), punctuated by intervening Early Permian deepening; basaltic eruptions during the mid Carboniferous and mid Permian; the onset of oceanic chert sedimentation close to the Carboniferous–Permian boundary and its persistence through the Late Triassic (Sowchea succession); latest Permian and Early Triassic mixed clastics and volcanics (Kloch Lake succession); Middle and Late Triassic reworking of carbonates (Whitefish limestone), including cavity fill in older limestones (Necoslie breccia), and fine-grained clastic sedimentation extending into the Early Jurassic (Tezzeron succession). Tethyan, eastern Pacific, and (or) low-latitude biogeographic attributes of the faunas are noted in the Gzhelian (fusulines), Artinskian (conodonts, fusulines), Wordian (fusulines, corals, conodonts), and Ladinian (conodonts, radiolarians). The Cache Creek Terrane lay far to the west of the North American continent during these times.

Palaeomagnetism, North China and South China collision, and the Tan-Lu fault

1990 ◽  
Vol 331 (1620) ◽  
pp. 589-598 ◽  
Keyword(s):  
South China ◽  
North China ◽  
Eastern China ◽  
Early Jurassic ◽  
Late Triassic ◽  
Polar Wander ◽  
The North ◽  
Indosinian Orogeny ◽  
North And South ◽  
Transcurrent Faults

Refined Apparent Polar Wander (APW) paths for the North and South China Blocks (ncb and scb) are presented and the collision between the NCB and SCB discussed. We suggest that the amalgamation of the NCB and SCB was completed in the late Triassic-early Jurassic, during the Indosinian Orogeny. This proposed timing is based on an analysis of palaeomagnetic signatures relating to continental collisions, such as the convergence of palaeolatitude, deflections of declination, hairpin-like loops in and superposition of APW paths. Like the Cenozoic India—Eurasia collision, the Mesozoic NCB- SCB collision reactivated ancient faults in eastern China, converting some of them into transcurrent faults, of which the Tan-Lu fault is the most famous.

Implications of Early Devonian poles from the Canadian Arctic Archipelago for the North American apparent polar wander path

1982 ◽  
Vol 19 (9) ◽  
pp. 1802-1809 ◽  
Author(s):  
Peter Dankers
Keyword(s):  
North American ◽  
Canadian Arctic ◽  
Canadian Arctic Archipelago ◽  
Early Devonian ◽  
Polar Wander ◽  
The North ◽  
Apparent Polar Wander Path ◽  
Late Cambrian ◽  
Normal Polarity ◽  
North American Craton

Lower Devonian red beds from the upper member of the Peel Sound Formation at Prince of Wales Island (Canadian arctic) yield two different paleopoles at 25N 099E and at 01N 091E, the first one being older than the second one. The magnetic directions from which the poles are calculated are derived from vector analysis of thermal, chemical, and alternating magnetic field demagnetization results. Normal and reversed polarities are recorded for the northerly pole, whereas the pole at the equator reveals mainly a normal polarity. The position of the pole close to the equator has significant implications for the early Paleozoic apparent polar wander path of the North American craton. It appears that from the Late Cambrian to Early Devonian the craton moved continuously in a counter-clockwise direction that ended abruptly in the Early Devonian when the direction of the motion of the continent was reversed in a very similar manner to what occurred in Late Cambrian times.

scholarly journals New insights on the early Mesozoic evolution of multiple tectonic regimes in the northeastern North China Craton from the detrital zircon provenance of sedimentary strata

Solid Earth ◽  
2018 ◽  
Vol 9 (6) ◽  
pp. 1375-1397 ◽  
Author(s):  
Yi Ni Wang ◽  
Wen Liang Xu ◽  
Feng Wang ◽  
Xiao Bo Li
Keyword(s):  
North China Craton ◽  
North China ◽  
Early Jurassic ◽  
Orogenic Belt ◽  
Detrital Zircons ◽  
Late Triassic ◽  
Early Triassic ◽  
The South ◽  
The North ◽  
Early Mesozoic

Abstract. To investigate the timing of deposition and provenance of early Mesozoic strata in the northeastern North China Craton (NCC) and to understand the early Mesozoic paleotectonic evolution of the region, we combine stratigraphy, U–Pb zircon geochronology, and Hf isotopic analyses. Early Mesozoic strata include the Early Triassic Heisonggou, Late Triassic Changbai and Xiaoyingzi, and Early Jurassic Yihe formations. Detrital zircons in the Heisonggou Formation yield  ∼ 58 % Neoarchean to Paleoproterozoic ages and  ∼ 42 % Phanerozoic ages and were sourced from areas to the south and north of the basins within the NCC, respectively. This indicates that Early Triassic deposition was controlled primarily by the southward subduction of the Paleo-Asian oceanic plate beneath the NCC and collision between the NCC and the Yangtze Craton (YC). Approximately 88 % of the sediments within the Late Triassic Xiaoyingzi Formation were sourced from the NCC to the south, with the remaining  ∼ 12 % from the Xing'an–Mongolia Orogenic Belt (XMOB) to the north. This implies that Late Triassic deposition was related to the final closure of the Paleo-Asian Ocean during the Middle Triassic and the rapid exhumation of the Su–Lu Orogenic Belt between the NCC and YC. In contrast,  ∼ 88 % of sediments within the Early Jurassic Yihe Formation were sourced from the XMOB to the north, with the remaining  ∼ 12 % from the NCC to the south. We therefore infer that rapid uplift of the XMOB and the onset of the subduction of the Paleo-Pacific Plate beneath Eurasia occurred in the Early Jurassic.

Paleomagnetism of the komatiitic basalts of the Ottawa Islands, N.W.T.

1985 ◽  
Vol 22 (4) ◽  
pp. 553-566 ◽  
Author(s):  
K. L. Buchan ◽  
W. R. A. Baragar
Keyword(s):  
North American ◽  
Hudson Bay ◽  
The West ◽  
Magnetization Direction ◽  
Polar Wander ◽  
The North ◽  
Dominant Component ◽  
Apparent Polar Wander Path

The komatiitic basalts of the Ottawa Islands in eastern Hudson Bay are on strike with and believed to form a continuation of similar units of the Cape Smith Belt 150 km to the northeast. Units sampled in the Ottawa Islands all dip gently to the west and hence are not suitable for an internal fold test of their age of magnetization. However, before correcting for the tilt of the lavas, the dominant magnetization direction (D = 207.6°, I = 61.9°, k = 168, α95 = 3.7°) does not differ significantly from the uncorrected magnetization direction reported from the steeply dipping, northwest-facing units at Cape Smith (D = 218°, I = 60°, k = 47, α95 = 4°). This negative fold test suggests that the remanence at both locations was acquired after folding. Comparison with the North American Precambrian apparent polar wander path implies that overprinting is related to the Hudsonian Orogeny.A second stable magnetization directed to the west with a shallow inclination is superimposed on the dominant component at a number of sampling sites. Its direction is poorly defined and no fold test is possible. However, magnetic evidence suggests that this component was probably acquired as an overprint after the dominant magnetization, perhaps during a mild reheating associated with the Elsonian Orogeny.

Japan's Position before the Outbreak of the European War in September 1939

1980 ◽  
Vol 14 (1) ◽  
pp. 129-143
Author(s):  
Kyozo Sato
Keyword(s):  
North China ◽  
Second World War ◽  
Pacific War ◽  
Military Operations ◽  
World War ◽  
War Of Attrition ◽  
The North ◽  
The Pacific ◽  
Second World ◽  
Made In

In the years leading up to the outbreak of war in Europe in early September 1939 Japan had been busy tackling the commitments she had made in North China at first and then in the whole of China. Although war was not declared, Japan had been at war with China since July 1937. It was a war of attrition; both Japan and China claimed to be winning, yet neither could, on any occasion, see any prospect of a final and definite victory. So long as Japan's military operations were confined to the area of North China, the war was named the ‘North China Incident.’ It was called the ‘China Incident’ after her successive and more or less successful operations had spread to Central and South China. And when a war broke out in the Pacific in December 1941 the Sino-Japanese war became an inseparable part of the ‘Greater East Asia War’ (Dai-tōa sensō), a name rarely heard by now, since it soon gave way to the ‘Pacific War’ (Taiheiyō sensō) in the sense of Japan waging the war of the Ocean, or to the ‘Second World War’ in the global sense.

Paleomagnetic and geobarometric study of the mid-Cretaceous Whitehorse Pluton, Yukon Territory

1997 ◽  
Vol 34 (10) ◽  
pp. 1379-1391 ◽  
Author(s):  
M. J. Harris ◽  
D. T. A. Symons ◽  
W. H. Blackburn ◽  
C. J. R. Hart
Keyword(s):  
United States ◽  
British Columbia ◽  
Crystallization Temperature ◽  
Remanent Magnetization ◽  
Average Rate ◽  
Yukon Territory ◽  
Canadian Cordillera ◽  
The North ◽  
North American Craton ◽  
High Level

This is the first of several Lithoprobe paleomagnetic studies underway to examine geotectonic motions in the northern Canadian Cordillera. Except for one controversial study, estimates for terranes underlying the Intermontane Belt in the Yukon have been extrapolated from studies in Alaska, southern British Columbia, and the northwestern United States. The Whitehorse Pluton is a large unmetamorphosed and undeformed tonalitic body of mid-Cretaceous age (~112 Ma) that was intruded into sedimentary units of the Whitehorse Trough in the Stikinia terrane. Geothermobarometric estimates for eight sites around the pluton indicate that postmagnetization tilting has been negligible since cooling through the hornblende-crystallization temperature and that the pluton is a high-level intrusion. Paleomagnetic measurements for 22 of 24 sites in the pluton yield a well-defined characteristic remanent magnetization (ChRM) direction that is steeply down and northwards. The ChRM direction gives a paleopole of 285.5°E, 81.7°N (dp = 53°, dm = 5.7°). When compared with the 112 Ma reference pole for the North American craton, this paleopole suggests that the northern Stikinia terrane has been translated northwards by 11.0 ± 4.8° (1220 ± 530 km) and rotated clockwise by 59 ± 17°. Except for an estimate from the ~70 Ma Carmacks Group volcanics, this translation and rotation estimate agrees well with previous estimates for units in the central and southern Intermontane Belt. They suggest that the terranes of the Intermontane Belt have behaved as a fairly coherent unit since the Early Cretaceous, moving northward at a minimum average rate of 2.3 ± 0.4 cm/a between ~140 and ~45 Ma.

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.

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