Upper mantle structure underlying the diamondiferous Slave craton from teleseismic body-wave tomography

Estève, Clément; Schaeffer, A. J.; Audet, Pascal

doi:10.1016/j.tecto.2019.01.012

Cited by 3 publications

(14 citation statements)

References 64 publications

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“…Therefore, the transition from low to high velocity in the central and eastern Slave craton is a resolved feature in our models, but we cannot confidently constrain its depth extent. This result is consistent with another regional teleseismic study conducted over this region (Estève et al, 2019).…”

Section: Kimberlite Fields In the Slave Craton And Surroundingssupporting

confidence: 93%

“…We use VanDecar's inversion procedure to resolve the three-dimensional isotropic velocity structure underlying northwestern Canada (VanDecar et al, 1995). This tomographic software has been applied to a variety of tectonic settings (e.g., subduction zones: Bostock & VanDecar, 1995;cratonic regions: Bastow et al, 2013;Bollmann et al, 2019;Boyce et al, 2016;Estève et al, 2019;Frederiksen et al, 2007;Mercier et al, 2009;Villemaire et al, 2012;and rift settings: Bastow et al, 2008;White-Gaynor et al, 2019). Relative delay times are inverted simultaneously for slowness perturbations, station static terms, and source terms.…”

Section: Inversion Proceduresmentioning

confidence: 99%

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The Upper Mantle Structure of Northwestern Canada From Teleseismic Body Wave Tomography

et al. 2020

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The Northern Canadian Cordillera (NCC) is an actively deforming orogenic belt in northwestern Canada. Geochemical and geophysical data show that the NCC is underlain by a thin and hot lithosphere, in contrast with the adjacent cold and thick cratonic lithosphere to the east. This juxtaposition of cold/hot and thick/thin lithosphere across a narrow transition zone has important implications for regional geodynamics. The recent deployment of USArray Transportable Array and other seismic stations across Alaska, USA, and northwestern Canada allows us to image lithosphere and upper mantle three‐dimensional seismic velocity structure at significantly improved resolution. Our model reveals a broad high‐velocity anomaly across northern Yukon and Northwest Territories, which is interpreted as buried cratonic lithosphere and which we refer to as the Mackenzie craton. Another prominent high‐velocity anomaly is imaged beneath northeastern British Columbia and is interpreted to indicate cratonic lithosphere beneath the Northern Rocky Mountains. These two mechanically strong lithospheric blocks, also suggested by regional magnetic data, are interpreted to buttress the ends of the Mackenzie Mountains fold and thrust belt, guiding intervening cordilleran mantle flow toward the Canadian Shield and controlling the arcuate geometry of the Mackenzie Mountains fold and thrust belt. Both P and S wave models also reveal the signature of a northward dipping, subducting Wrangell slab across the southern region of the Alaska/Yukon border. Strong P and S wave velocity contrasts across the Tintina Fault suggest that it is a lithosphere‐scale shear zone that extends into the upper mantle beneath the NCC and demarcates distinct regions of lithospheric mantle.

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Section: Kimberlite Fields In the Slave Craton And Surroundingssupporting

confidence: 93%

Section: Inversion Proceduresmentioning

confidence: 99%

The Upper Mantle Structure of Northwestern Canada From Teleseismic Body Wave Tomography

et al. 2020

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“…(1998) placed the boundary of Precambrian North American lithosphere west of the Tintina Fault and Mercier et al. (2009) suggest this boundary underlies the CDF in northwest Canada, more recent studies suggest that low wavespeeds continue beyond the CDF, east of the Mackenzie Mountains toward the Slave craton (Estève et al., 2019, 2020). CAP22 also shows slow wavespeeds to continue eastward throughout the Slave craton, with the abrupt change spatially correlated with the LLTZ.…”

Section: Results and Comparisons With Previous Studiesmentioning

confidence: 99%

“…However, the physical extent and compositional character of this modification is uncertain because petrological analyses are typically conducted on spatially limited xenolith samples (Aulbach et al., 2013; Heaman & Pearson, 2010) and variably resolving geophysical studies (Bostock, 1998; Bank et al., 2000; C.‐W. Chen et al., 2007, 2009; Schaeffer & Lebedev, 2014; Eeken et al., 2018; Estève et al., 2019, 2020).…”

Section: Introductionmentioning

confidence: 99%

“…In North America, deployment of the USArray Transportable Array (TA) seismic network across the contiguous United States has produced numerous new tectonic insights using seismic tomography (e.g., Schaeffer & Lebedev, 2014; Schmandt & Lin, 2014). However, the termination of the USArray deployment at or near the US‐Canadian border, across which many significant geological boundaries traverse (Figure 1), has by comparison, largely limited seismological insights into the Canadian mantle to regional studies using temporary seismic networks (e.g., Mercier et al., 2009; Frederiksen et al., 2013; Bao et al., 2014; Boyce et al., 2016; Liddell et al., 2018; Y. Chen et al., 2019; Estève et al., 2019, 2020).…”

Section: Introductionmentioning

confidence: 99%

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A New P‐Wave Tomographic Model (CAP22) for North America: Implications for the Subduction and Cratonic Metasomatic Modification History of Western Canada and Alaska

et al. 2023

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Our understanding of the present‐day state and evolution of the Canadian and Alaskan mantle is hindered by a lack of absolute P‐wavespeed constraints that provide complementary sensitivity to composition in conjunction with existing S‐wavespeed models. Consequently, cratonic modification, orogenic history of western North America and complexities within the Alaskan Proto‐Pacific subduction system remain enigmatic. One challenge concerns the difficulties in extracting absolute arrival‐time measurements from often‐noisy data recorded by temporary seismograph networks required to fill gaps in continental and global databases. Using the Absolute Arrival‐time Recovery Method (AARM), we extract >180,000 new absolute arrival‐time residuals from seismograph stations across Canada and Alaska and combine these data with USArray and global arrival‐time data from the contiguous US and Alaska. We develop a new absolute P‐wavespeed tomographic model, CAP22, spanning North America that significantly improves resolution in Canada and Alaska over previous models. Slow wavespeeds below the Canadian Cordillera sharply abut fast wavespeeds of the continental interior at the Rocky Mountain Trench in southwest Canada. Slow wavespeeds below the Mackenzie Mountains continue farther inland in northwest Canada, indicating Proterozoic‐Archean metasomatism of the Slave craton. Inherited tectonic lineaments colocated with this north‐south wavespeed boundary suggest that both the crust and mantle may control Cordilleran orogenic processes. In Alaska, fast upper mantle wavespeeds below the Wrangell Volcanic Field favor a conventional subduction related mechanism for volcanism. Finally, seismic evidence for the subducted Kula and Yukon slabs indicate tectonic reconstructions of western North America may require revision.

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Metasomatic control of hydrogen contents in the layered cratonic mantle lithosphere sampled by Lac de Gras xenoliths in the central Slave craton, Canada

Kilgore

Peslier

Brandon

et al. 2020

Geochimica et Cosmochimica Acta

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Upper mantle structure underlying the diamondiferous Slave craton from teleseismic body-wave tomography

Cited by 3 publications

References 64 publications

The Upper Mantle Structure of Northwestern Canada From Teleseismic Body Wave Tomography

The Upper Mantle Structure of Northwestern Canada From Teleseismic Body Wave Tomography

A New P‐Wave Tomographic Model (CAP22) for North America: Implications for the Subduction and Cratonic Metasomatic Modification History of Western Canada and Alaska

Metasomatic control of hydrogen contents in the layered cratonic mantle lithosphere sampled by Lac de Gras xenoliths in the central Slave craton, Canada

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