scholarly journals Evolution of the Jura-Cretaceous North American Cordilleran margin: Insights from detrital-zircon U-Pb and Hf isotopes of sedimentary units of the North Cascades Range, Washington

Geosphere ◽  
2017 ◽  
Vol 13 (6) ◽  
pp. 2094-2118 ◽  
Author(s):  
Kirsten B. Sauer ◽  
Stacia M. Gordon ◽  
Robert B. Miller ◽  
Jeffrey D. Vervoort ◽  
Christopher M. Fisher
Keyword(s):  
North American ◽  
Detrital Zircon ◽  
Hf Isotopes ◽  
North Cascades ◽  
The North ◽  
Cordilleran Margin

scholarly journals TIMING AND DRIVERS OF EXHUMATION IN THE HINTERLAND OF THE NORTH AMERICAN CORDILLERA FROM DETRITAL ZIRCON U-PB AND (U-TH)/HE DOUBLE-DATING

2017 ◽  
Author(s):  
Kathleen A. Graham ◽  
◽  
Tandis S. Bidgoli ◽  
J. Douglas Walker ◽  
Andreas Möller
Keyword(s):  
North American ◽  
Detrital Zircon ◽  
North American Cordillera ◽  
The North

U–Pb geochronology of detrital zircons from a continental margin assemblage in the northern Coast Mountains, southeastern Alaska

1991 ◽  
Vol 28 (8) ◽  
pp. 1285-1300 ◽  
Author(s):  
George E. Gehrels ◽  
William C. McClelland ◽  
Scott D. Samson ◽  
P. Jonathan Patchett
Keyword(s):  
Continental Margin ◽  
North American ◽  
Detrital Zircons ◽  
Northern Coast ◽  
Coast Mountains ◽  
Metasedimentary Rocks ◽  
The North ◽  
Upper Proterozoic ◽  
Two Samples ◽  
Cordilleran Margin

Metamorphic rocks within and west of the northern Coast Mountains in southeastern Alaska consist of an Upper Proterozoic(?) to upper Paleozoic continental margin assemblage that we interpret to belong to the Yukon-Tanana terrane. U–Pb geochronologic analyses of single detrital zircon grains from four samples of quartzite suggest that the zircons were shed from source regions containing rocks of ~495 Ma, ~750 Ma, 1.05–1.40 Ga, 1.75–2.00 Ga, ~2.3 Ga, 2.5–2.7 Ga, and ~3.0 Ga. Multigrain fractions from two samples yield upper intercepts between 2.0 and 2.3 Ga, but the scarcity of single grains of similar age suggests that these fractions comprise a mixture of < 2.0 and > 2.3 Ga grains. Zircons in these rocks generally overlap in age with (i) detrital zircons in metasedimentary rocks of the Yukon–Tanana terrane in eastern Alaska and Yukon, (ii) detrital zircons in strata of the Cordilleran miogeocline, and (iii) plutonic and gneissic rocks that intrude or are overlain by miogeoclinal strata. In addition, the pre-1.7 Ga grains overlap in age with dated crystalline rocks of the western Canadian Shield. These similarities raise the possibility that metaclastic rocks in the northern Coast Mountains accumulated in proximity to western North America. The younger zircon populations were likely shed from mid-Proterozoic to early Paleozoic igneous rocks that now occur locally (but may have been widespread) along the Cordilleran margin. Recognition of a continental margin assemblage of possible North American affinity in the Coast Mountains raises the possibility that some arc-type and oceanic terranes inboard of the Coast Mountains may be large klippen that have been thrust over the North American margin.

Ancestral trans−North American Bell River system recorded in late Oligocene to early Miocene sediments in the Labrador Sea and Canadian Great Plains

2021 ◽  
Author(s):  
Julia I. Corradino ◽  
Alex Pullen ◽  
Andrew L. Leier ◽  
David L. Barbeau Jr. ◽  
Howie D. Scher ◽  
...  
Keyword(s):  
North America ◽  
Great Plains ◽  
North American ◽  
Detrital Zircon ◽  
Detrital Zircons ◽  
Labrador Sea ◽  
Western Canada ◽  
Zircon Age ◽  
North American Cordillera ◽  
The North

The Bell River hypothesis proposes that an ancestral, transcontinental river occupied much of northern North America during the Cenozoic Era, transporting water and sediment from the North American Cordillera to the Saglek Basin on the eastern margin of the Labrador Sea. To explore this hypothesis and reconstruct Cenozoic North American drainage patterns, we analyzed detrital zircon grains from the Oligocene−Miocene Mokami and Saglek formations of the Saglek Basin and Oligocene−Miocene fluvial conglomerates in the Great Plains of western Canada. U-Pb detrital zircon age populations in the Mokami and Saglek formations include clusters at &lt;250 Ma, 950−1250 Ma, 1600−2000 Ma, and 2400−3200 Ma. Detrital zircons with ages of &lt;250 Ma were derived from the North American Cordillera, supporting the transcontinental Bell River hypothesis. Oligocene−Miocene fluvial strata in western Canada contain detrital zircon age populations similar to those in the Saglek Basin and are interpreted to represent the western headwaters of the ancient Bell River drainage. Strontium-isotope ratios of marine shell fragments from the Mokami and Saglek formations yielded ages between 25.63 and 18.08 Ma. The same shells have εNd values of −10.2 to −12.0 (average = −11.2), which are consistent with values of Paleozoic strata in western North America but are more radiogenic than the modern Labrador Current, Labrador Sea Water, and North Atlantic Deep Water values (εNd ∼−12 to −25). As a freshwater source, the existence and termination of the Bell River may have been important for Labrador Sea circulation, stratification, and chemistry.

Middle–late Mesoproterozoic tectonic geography of the North Australia Craton: U–Pb and Hf isotopes of detrital zircon grains in the Beetaloo Sub-basin, Northern Territory, Australia

2019 ◽  
Vol 176 (4) ◽  
pp. 771-784 ◽  
Author(s):  
B. Yang ◽  
A. S. Collins ◽  
M. L. Blades ◽  
N. Capogreco ◽  
J. L. Payne ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Northern Territory ◽  
Hf Isotopes ◽  
The North

scholarly journals Detrital zircon record of magmatism and sediment dispersal across the North American Cordilleran arc system (28–48°N)

2021 ◽  
pp. 103734
Author(s):  
Theresa M. Schwartz ◽  
Kathleen D. Surpless ◽  
Joseph P. Colgan ◽  
Samuel A. Johnstone ◽  
Christopher S. Holm-Denoma
Keyword(s):  
North American ◽  
Detrital Zircon ◽  
Sediment Dispersal ◽  
The North
Sign in / Sign up

Export Citation Format

Share Document