Nd isotopic evidence from Wopmay Orogen for 2.0–2.4 Ga crust in western North America

Bowring, Samuel A.; Podosek, F. A.

doi:10.1016/0012-821x(89)90141-6

Cited by 73 publications

(32 citation statements)

References 42 publications

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“…2.0-2.4 Ga crustal basement (Bowring and Podosek 1989). Our new Nd isotopic results are similar ( Fig.…”

Section: Whence Came Hottah Terrane?supporting

confidence: 78%

“…1876 Ma (Bowring 1984;Hildebrand et al 2010a;Jackson et al 2013). In addition, detrital zircons and Nd and Pb isotope data do not support that the Hottah terrane was built on attenuated Slave craton crust (Bowring and Podosek 1989;Housh et al 1989;Hildebrand et al 2010a;Davis et al 2015). The simple marginal basin model entirely within Slave crust, depicted in Fig.…”

Section: Whence Came Hottah Terrane?mentioning

confidence: 91%

“…1.88 Ga (Fig. 4A;Hildebrand 1981;Bowring and Podosek 1989;Bowring and Grotzinger 1992;Hildebrand et al 2010a;Hoffman et al 2011;Hoffman 2012). The time frame of the transition from Coronation passive to active margin sedimentation (ca.…”

Section: Geological Settingmentioning

confidence: 98%

“…The Wopmay fault zone is a north-south-striking crustal-scale fault that delimits the western extent of exposed Archean rocks in the Wopmay Orogen (Figs. 1, 2;St-Onge et al 1983;King 1986;Bowring and Podosek 1989;Housh et al 1989;Jackson 2008;Jackson et al 2006Jackson et al , 2013Spratt et al 2009;Jackson and Ootes 2012: also called medial zone by Hildebrand et al 1991Hildebrand et al , 2010a. West of Wopmay fault zone are the remnants of the >1.9 Ga Hottah terrane, which was extensively overprinted by ca.…”

Section: Geological Settingmentioning

confidence: 99%

“…The depleted mantle model ages (T DM ) range from 2.2 to 2.5 Ga (Table 3). One interpretation is that these could represent an accurate measure of a crustal protolith age (e.g., Bowring and Podosek 1989). Alternatively, these values record a mixture of juvenile mantle and a crustal end member, as is typical of igneous rocks in magmatic arc settings.…”

Section: Whence Came Hottah Terrane?mentioning

confidence: 99%

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Chronostratigraphy of the Hottah terrane and Great Bear magmatic zone of Wopmay Orogen, Canada, and exploration of a terrane translation model

et al. 2015

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Abstract:The Paleoproterozoic Hottah terrane is the westernmost exposed bedrock of the Canadian Shield and a critical component for understanding the evolution of the Wopmay Orogen. Thirteen new high-precision U-Pb zircon crystallization ages are presented and support field observations of a volcano-plutonic continuum from Hottah terrane through to the end of the Great Bear magmatism, from >1950 to 1850 Ma. The new crystallization ages, new geochemical data, and newly published detrital zircon U-Pb data are used to challenge hitherto accepted models for the evolution of the Hottah terrane as an exotic arc and microcontinent that arrived over a west-dipping subduction zone and collided with the Slave craton at ca. 1.88 Ga. Although the Hottah terrane does have a tectonic history that is distinct from that of the neighbouring Slave craton, it shares a temporal history with a number of domains to the south and east -domains that were tied to the Slave craton by ca. 1.97 Ga. It is interpreted herein that Hottah terrane began to the south of its current position and evolved in an active margin over an always east-dipping subduction system that began prior to ca. 2.0 Ga and continued to ca. 1.85 Ga, and underwent tectonic switching and migration. The stratigraphy of the ca. 1913-1900 Ma Hottah plutonic complex and Bell Island Bay Group includes a subaerial rifting arc sequence, followed by basinal opening represented by marginal marine quartz arenite and overlying ca. 1893 Ma pillowed basalt flows and lesser rhyodacites. We interpret this stratigraphy to record Hottah terrane rifting off its parental arc crust -in essence the birth of the new Hottah terrane. This model is similar to rapidly rifting arcs in active margins -for example, modern Baja California. These rifts generally occur at the transition between subduction zones (e.g., Cocos-Rivera plates) and transtensional shear zones (e.g., San Andreas fault), and we suggest that extension-driven transtensional shearing, or, more simply, terrane translation, was responsible for the evolution of Bell Island Bay Group stratigraphy and that it transported this newly born Hottah terrane laterally (northward in modern coordinates), arriving adjacent to the Slave craton at ca. 1.88 Ga. Renewed east-dipping subduction led to the Great Bear arc flare-up at ca. 1876 Ma, continuing to ca. 1869 Ma. This was followed by voluminous Great Bear plutonism until ca. 1855 Ma. The model implies that it was the westerly Nahanni terrane and its subducting oceanic crust that collided with this active margin, shutting down the >120 million year old, east-dipping subduction system.

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“…2.0-2.4 Ga crustal basement (Bowring and Podosek 1989). Our new Nd isotopic results are similar ( Fig.…”

Section: Whence Came Hottah Terrane?supporting

confidence: 78%