Petrology and Tectonic Significance of Gabbros, Tonalites, Shoshonites, and Anorthosites in a Late Paleozoic Arc-Root Complex in the Wrangellia Terrane, Southern Alaska

1989 ◽  
Vol 97 (6) ◽  
pp. 667-683 ◽  
Author(s):  
James S. Beard ◽  
Fred Barker
Keyword(s):  
Late Paleozoic ◽  
Tectonic Significance ◽  
Wrangellia Terrane ◽  
Arc Root

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.

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

Petrochemistry and tectonic significance of Carboniferous volcanic rocks in New Brunswick

1986 ◽  
Vol 23 (9) ◽  
pp. 1243-1256 ◽  
Author(s):  
L. R. Fyffe ◽  
S. M. Barr
Keyword(s):  
New Brunswick ◽  
Tectonic Setting ◽  
Volcanic Rocks ◽  
Age Groups ◽  
Late Paleozoic ◽  
Basement Rocks ◽  
Basaltic Composition ◽  
Tectonic Significance ◽  
Maritimes Basin ◽  
Alkalic Basalts

Carboniferous volcanic rocks from the New Brunswick Platform in the Maritimes Basin are divided into three age groups. Late Tournaisian to early Visean volcanic rocks are tholeiitic basalts and andesites that, in southern New Brunswick, are inter-bedded with abundant calc-alkalic rhyolite. Late Visean to Namurian volcanic rocks consist of an interbedded sequence of alkalic basalts and trachyandesites. Late Westphalian volcanic rocks change in composition up section from trachyte to peralkalic rhyolite. All three age groups display petrochemical features indicative of an intraplate tectonic setting. The volcanic geochemistry is consistent with the development of the Maritimes Basin either as a failed rift formed along the margin of a late Paleozoic ocean or as a rhomb graben formed within a transcurrent zone; the former model is preferred. The change in basaltic composition from tholeiitic to alkalic apparently coincided with a decrease in rate of extension between the Tournaisian and Namurian. Local peralkalic volcanism occurred during regional sagging of the basin as extension ceased and basement rocks cooled in the Late Carboniferous.

Late Paleozoic tectonism in Nevada: Timing, kinematics, and tectonic significance

2004 ◽  
Vol 116 (5) ◽  
pp. 525 ◽  
Author(s):  
James H. Trexler, ◽  
Patricia H. Cashman ◽  
Walter S. Snyder ◽  
Vladimir I. Davydov
Keyword(s):  
Late Paleozoic ◽  
Tectonic Significance
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