scholarly journals Tectonic significance of Late Paleozoic deformation in the Cape George Peninsula, Antigonish Highlands, Nova Scotia

10.4138/1987 ◽  
1993 ◽  
Vol 29 (1) ◽  
Author(s):  
J. A.R. St. Jean ◽  
R. D. Nance ◽  
J. B. Murphy
Keyword(s):  
Nova Scotia ◽  
Late Paleozoic ◽  
Tectonic Significance

scholarly journals Superposed Late Paleozoic thermal events in the southwestern Meguma Terrane, Nova Scotia

10.4138/1648 ◽  
1988 ◽  
Vol 24 (2) ◽  
Author(s):  
R. D. Dallmeyer ◽  
J. D. Keppie
Keyword(s):  
Nova Scotia ◽  
Late Paleozoic ◽  
Meguma Terrane

Eclogitic rocks in the St. Cyr klippe, Yukon, and their tectonic significance

1992 ◽  
Vol 29 (6) ◽  
pp. 1296-1304 ◽  
Author(s):  
Philippe Erdmer
Keyword(s):  
High Pressure ◽  
Oceanic Crust ◽  
North American ◽  
Suture Zone ◽  
Late Paleozoic ◽  
The North ◽  
Tectonic Significance ◽  
Subducted Oceanic Crust ◽  
Ophiolitic Rocks ◽  
Subducting Slab

Until recently, the Nisutlin allochthonous assemblage, a part of the Yukon–Tanana composite terrane interpreted as trench mélange from a late Paleozoic – Mesozoic arc system, was the only tectonic assemblage known to include subducted material in the northern Cordillera. The discovery of eclogitic rocks in two parts of a klippe of the Anvil allochthonous assemblage, which comprises mafic ophiolitic rocks, above the Cassiar terrane west of the Tintina fault confirms other evidence that subducted oceanic crust was also returned to the surface. The eclogitic rocks have been largely retrograded by postsubduction metamorphism. Their existence is interpreted as additional evidence of the link between nappes above the Cassiar terrane and their inferred root, the Teslin suture zone. The Nisutlin and Anvil allochthonous assemblages can now be interpreted, not simply as crustally metamorphosed assemblages with minor, structurally interleaved high-pressure components, but as deeply metamorphosed and intensely strained slices of continental and oceanic crust switched from subducting slab to overriding plate and returned to the surface during collision of the arc with the North American margin.

Kennetcook thrust system: late Paleozoic transpression near the southern margin of the Maritimes Basin, Nova Scotia

2010 ◽  
Vol 47 (2) ◽  
pp. 137-159 ◽  
Author(s):  
John W.F. Waldron ◽  
Carlos G. Roselli ◽  
John Utting ◽  
Stanley K. Johnston
Keyword(s):  
Nova Scotia ◽  
Early Carboniferous ◽  
Late Paleozoic ◽  
The South ◽  
Seismic Profiles ◽  
Southern Margin ◽  
Fault Structures ◽  
Thrust System ◽  
Maritimes Basin

A major zone of deformation affects Early Carboniferous rocks in the southern part of the Maritimes Basin of Nova Scotia, close to the boundary between the Avalon and Meguma terranes of the Appalachians. Field relationships at Cheverie indicate thrusting of Tournaisian Horton Group clastics over Viséan Windsor Group carbonates, evaporites, and clastics, a relationship confirmed by the Cheverie #01 well. Mapped relationships to the south indicate that a system of thrusts, here termed the Kennetcook thrust system, climbs upsection to the southeast, becoming a décollement within Windsor Group evaporites. Industry seismic profiles clearly show deformed Windsor Group, and include fold and fault structures indicative of evaporite flow and solution collapse. Below the Windsor Group, half-grabens filled with Horton Group are clearly imaged; offsets at graben-related faults show that these structures were inverted during later shortening. Above the Windsor Group, less deformed rocks of the Pennsylvanian Scotch Village Formation (Cumberland Group) fill minibasins created by the withdrawal or solution of deformed Windsor evaporites. The timing of thrusting is constrained by these relationships and by crosscutting intrusions to a narrow interval around the Mississippian–Pennsylvanian boundary prior to ∼315 Ma. Deformation was probably related to dextral transpression along the former Avalon–Meguma boundary. Depending on how shortening was transmitted to the southeast, up to 1500 km2 of southern mainland Nova Scotia may be underlain by tectonically transported rocks.

Thermochronologic constraints on ore formation at the Gays River Pb–Zn deposit, Nova Scotia, Canada, from apatite fission track analysis

1990 ◽  
Vol 27 (8) ◽  
pp. 1013-1022 ◽  
Author(s):  
Dennis C. Arne ◽  
Ian R. Duddy ◽  
Don F. Sangster
Keyword(s):  
Nova Scotia ◽  
Fission Track ◽  
Track Length ◽  
Late Paleozoic ◽  
Apatite Fission Track ◽  
Ore Formation ◽  
Sulphide Mineralization ◽  
Fission Track Ages ◽  
Uplift And Erosion ◽  
Host Rocks

Fission tracks in detrital apatites from the Cambro-Ordovician metasedimentary basement in the vicinity of the Carboniferous-hosted Gays River Pb–Zn deposit, Nova Scotia, provide a record of final cooling during uplift and erosion of the Meguma Zone and constrain the timing of ore formation. Apatite fission track ages range from 203 to 241 Ma, with typical uncertainties of ± 10 Ma. Mean confined track lengths generally vary between 12.0 and 13.4 μm and indicate that the apatites record "apparent" ages only. An inferred thermal history involving regional heating to paleotemperatures > 110 °C during late Paleozoic burial followed by cooling to ~ 110 °C prior to 240–220 Ma is suggested. A more recent phase or regional heating to paleotem-peratures probably in the range of 60–80 °C during Late Cretaceous – early Tertiary (ca. 100–50 Ma) burial is also indicated by the track length data. Apatite fission track ages and mean track lengths from drill-core samples immediately beneath the Gays River orebody are similar to those for regional outcrop samples. At minimum temperatures > 200 °C estimated for ore formation, sulphide mineralization must either have preceded or accompanied regional heating to paleotemperatures > 110 °C during the late Paleozoic. Sulphide mineralization at Gays River must therefore have taken place at some time after ca. 330 Ma (the stratigraphic age of the lower Windsor Group host rocks) but before ca. 240–220 Ma (the last cooling of Meguma Group basement below 110 °C). These constraints on the timing of ore formation at Gays River are compatible with previous suggestions that Pb–Zn mineralization of Carboniferous strata in Nova Scotia occurred at ca. 300 Ma.

Late Paleozoic polar wander path for the Tarim platform and its tectonic significance

1987 ◽  
Vol 139 (1-2) ◽  
pp. 145-153 ◽  
Author(s):  
Yunhong Bai ◽  
Guoliang Chen ◽  
Qingge Sun ◽  
Yuhang Sun ◽  
Yongan Li ◽  
...  
Keyword(s):  
Late Paleozoic ◽  
Polar Wander ◽  
Tectonic Significance

Paleomagnetism of the Cumberland Group and other Paleozoic formations

1969 ◽  
Vol 6 (4) ◽  
pp. 663-669 ◽  
Author(s):  
J. L. Roy
Keyword(s):  
Nova Scotia ◽  
Late Paleozoic ◽  
Geological Evidence ◽  
Thermal Demagnetization ◽  
Constant Polarity ◽  
Red Bed

Thermal demagnetization of red bed samples from the Cumberland Group (Pennsylvanian) of Nova Scotia indicates that the fossil magnetization is composed mainly of a thermally distributed (up to 650 °C) magnetization. The direction changes between heatings are small, indicating that this magnetization was acquired in a field of constant polarity. A fold test (10 sites) shows that the magnetization predates the folding, which according to geological evidence occurred shortly after deposition. The results (direction 172°, + 16°; k = 85; pole 36 °N, 125° E) are compared with other results obtained from Paleozoic formations. Comparison between continents indicate that a 30° apparent polar change during the Paleozoic is probable. From the Dominion Observatory results, it is suggested that at least half of the change took place during late Paleozoic times and probably during the Pennsylvanian Period.

scholarly journals Late Paleozoic motions of the Meguma terrane, Nova Scotia: New paleomagnetic evidence

1984 ◽  
pp. 82-98 ◽  
Author(s):  
Dann J. Spariosu ◽  
Dennis V. Kent ◽  
J. Duncan Keppie
Keyword(s):  
Nova Scotia ◽  
Late Paleozoic ◽  
Meguma Terrane
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