Late Proterozoic–Paleozoic evolution of the Arctic Alaska–Chukotka terrane based on U-Pb igneous and detrital zircon ages: Implications for Neoproterozoic paleogeographic reconstructions

2009 ◽  
Vol 121 (9-10) ◽  
pp. 1219-1235 ◽  
Author(s):  
Jeffrey M. Amato ◽  
Jaime Toro ◽  
Elizabeth L. Miller ◽  
George E. Gehrels ◽  
G. Lang Farmer ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
The Arctic ◽  
Late Proterozoic ◽  
Arctic Alaska ◽  
Detrital Zircon Ages

Precambrian U–Pb ages of igneous rocks, Wrangel Complex, Wrangel Island, USSR

1991 ◽  
Vol 28 (9) ◽  
pp. 1340-1348 ◽  
Author(s):  
M. P. Cecile ◽  
J. C. Harrison ◽  
M. K. Kos'ko ◽  
R. R. Parrish
Keyword(s):  
Volcanic Rocks ◽  
Canadian Arctic ◽  
Canada Basin ◽  
The Arctic ◽  
Porphyritic Granite ◽  
Late Proterozoic ◽  
Wrangel Island ◽  
Arctic Alaska ◽  
Continuous Plate ◽  
Orogenic Events

Proterozoic rocks exposed in an anticlinorium at the centre of Wrangel Island are among some of the few exposures of Precambrian strata around Canada Basin. U–Pb zircon dating of samples collected during joint Canadian–Soviet fieldwork on the island has provided crystallization ages of [Formula: see text] on a volcanic rock, 699 ± 2 Ma on a porphyritic granite sill, and a very imprecise age of ca. 0.7 Ga on a small leucogranite. Broadly similar 600–750 Ma, mostly metamorphic, ages are known from both the Arctic Alaska and northern Chukotkan parts of what is called the Arctic Alaska – Chukotka Ancestral Plate, supporting the hypothesis that they were once a single entity. By contrast, potential Late Proterozoic equivalents in the Canadian Arctic Islands include a deeply buried and relatively undeformed seismically defined succession of hypothesized Late Proterozoic age, now at greenschist-facies metamorphic grade, and the unmetamorphosed 725 Ma Franklin mafic sills, dykes, and volcanic rocks. The differences in metamorphic and igneous ages between the Arctic Alaska–Chukotka Ancestral Plate and the Canadian Arctic Islands suggest that these two areas have fundamentally different Precambrian rocks. If so, this challenges the fundamental assumption of most paleogeographic models of the pre-Canada Basin Arctic that the two areas once formed a single continuous plate. Earlier K–Ar dates together with major unconformities in Phanerozoic successions on Wrangel Island suggest early Paleozoic orogenic events.

A detrital zircon test of large-scale terrane displacement along the Arctic margin of North America

Geology ◽  
2021 ◽  
Author(s):  
Timothy M. Gibson ◽  
Karol Faehnrich ◽  
James F. Busch ◽  
William C. McClelland ◽  
Mark D. Schmitz ◽  
...  
Keyword(s):  
North America ◽  
Detrital Zircon ◽  
Large Scale ◽  
Small Sample ◽  
The Arctic ◽  
North Slope ◽  
The North ◽  
Arctic Alaska ◽  
Laurentian Margin ◽  
Small Sample Sizes

Detrital zircon U-Pb geochronology is one of the most common methods used to constrain the provenance of ancient sedimentary systems. Yet, its efficacy for precisely constraining paleogeographic reconstructions is often complicated by geological, analytical, and statistical uncertainties. To test the utility of this technique for reconstructing complex, margin-parallel terrane displacements, we compiled new and previously published U-Pb detrital zircon data (n = 7924; 70 samples) from Neoproterozoic–Cambrian marine sandstone-bearing units across the Porcupine shear zone of northern Yukon and Alaska, which separates the North Slope subterrane of Arctic Alaska from northwestern Laurentia (Yukon block). Contrasting tectonic models for the North Slope subterrane indicate it originated either near its current position as an autochthonous continuation of the Yukon block or from a position adjacent to the northeastern Laurentian margin prior to >1000 km of Paleozoic–Mesozoic translation. Our statistical results demonstrate that zircon U-Pb age distributions from the North Slope subterrane are consistently distinct from the Yukon block, thereby supporting a model of continent-scale strike-slip displacement along the Arctic margin of North America. Further examination of this dataset highlights important pitfalls associated with common methodological approaches using small sample sizes and reveals challenges in relying solely on detrital zircon age spectra for testing models of terranes displaced along the same continental margin from which they originated. Nevertheless, large-n detrital zircon datasets interpreted within a robust geologic framework can be effective for evaluating translation across complex tectonic boundaries.

DETRITAL ZIRCON AGES REVEAL POST 15 MA CONVERGENCE AND PLEISTOCENE-QUATERNARY BASEMENT UNROOFING IN THE CAUCASUS

2017 ◽  
Author(s):  
Alexander Tye ◽  
◽  
Nathan A. Niemi ◽  
Rafiq Safarov ◽  
Fakhraddin Kadirov
Keyword(s):  
Detrital Zircon ◽  
The Caucasus ◽  
Detrital Zircon Ages
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