CAN‐HK: An a Priori Crustal Model for the Canadian Shield

Thompson, David; Kendall, J.‐M.; Helffrich, George; Bastow, I. D.; Wookey, James; Snyder, David B.

doi:10.1785/0220150015

Cited by 7 publications

(4 citation statements)

References 39 publications

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“…The UK Hudson Bay Lithospheric Experiment (e.g., Bastow et al, 2015) involved seismometers installed on the northern islands of the Hudson Strait and Baffin Island, complementing the existing POLARIS network (Eaton et al, 2005) and increasing the resolution in the northern part of the Bay dramatically. These, in combination with other seismograph networks, have been used to provide improved insight into the crustal structure (e.g., Gilligan et al, 2016;Pawlak et al, 2011Pawlak et al, , 2012Thompson et al, 2010Thompson et al, , 2015, mantle wave speed (e.g., Darbyshire et al, 2013), and mantle anisotropy (e.g., Bastow et al, 2011;Liddell et al, 2017;Snyder et al, 2013). Based on two-station path-averaged Rayleigh wave dispersion analysis, Darbyshire and Eaton (2010) found no seismic wave speed distinction between Archean and Proterozoic mantle.…”

Section: Previous Geophysical Studiesmentioning

confidence: 99%

Precambrian Plate Tectonics in Northern Hudson Bay: Evidence From P and S Wave Seismic Tomography and Analysis of Source Side Effects in Relative Arrival‐Time Data Sets

et al. 2018

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The geology of northern Hudson Bay, Canada, documents more than 2 billion years of history including the assembly of Precambrian and Archean terranes during several Paleoproterozoic orogenies, culminating in the Trans‐Hudson Orogen (THO) ∼1.8 Ga. The THO has been hypothesized to be similar in scale and nature to the ongoing Himalaya‐Karakoram‐Tibetan orogen, but the nature of lithospheric terrane boundaries, including potential plate‐scale underthrusting, is poorly understood. To address this problem, we present new P and S wave tomographic models of the mantle seismic structure using data from recent seismograph networks stretching from northern Ontario to Nunavut (60–100∘W and 50–80∘N). The large size of our network requires careful mitigation of the influence of source side structure that contaminates our relative arrival time residuals. Our tomographic models reveal a complicated internal structure in the Archean Churchill plate. However, no seismic wave speed distinction is observed across the Snowbird Tectonic Zone, which bisects the Churchill. The mantle lithosphere in the central region of Hudson Bay is distinct from the THO, indicating potential boundaries of microcontinents and lithospheric blocks between the principal colliders. Slow wave speeds underlie southern Baffin Island, the leading edge of the generally high wave speed Churchill plate. This is interpreted to be Paleoproterozoic material underthrust beneath Baffin Island in a modern‐style subduction zone setting.

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Section: Previous Geophysical Studiesmentioning

confidence: 99%

Precambrian Plate Tectonics in Northern Hudson Bay: Evidence From P and S Wave Seismic Tomography and Analysis of Source Side Effects in Relative Arrival‐Time Data Sets

et al. 2018

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“…In addition to crustal structure information from studies specific to these three regions, a significant number of measurements of crustal thickness have been made using Canada‐wide receiver function analyses [e.g., Cassidy , ; Postlethwaite et al , ; Thompson et al , ] and ambient‐noise tomography [ Kao et al , ]. The large extent of the USArray Transportable Array also led to a new set of systematic automated measurements of Moho depths across the U.S. and Canada from receiver function analysis through the EARS program [ Trabant et al , ].…”

Section: Seismic Properties Of the Crust: A Reviewmentioning

confidence: 99%

A tale of two orogens: Crustal processes in the Proterozoic Trans‐Hudson and Grenville Orogens, eastern Canada

et al. 2017

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The Precambrian core of North America was assembled in the Proterozoic by a series of collisions between Archean cratons. Among the orogenic belts, two stand out due to their significant spatial extent. The Paleoproterozoic Trans‐Hudson Orogen (THO) and Mesoproterozoic Grenville Orogen extend for thousands of kilometers along strike and hundreds of kilometers across strike. Both have been compared to the present‐day Himalayan‐Karakoram‐Tibetan Orogen (HKTO). Over the last 20–30 years, active and passive source seismic studies have contributed a wealth of information about the present‐day crustal structure and composition of the two orogens in Canada. The Proterozoic orogenic crust is generally thicker than that of neighboring Archean terranes, with a more variable Moho character, ranging from relatively sharp to highly diffuse. Both orogens have a prominent high‐velocity lower crustal layer, consistent with long‐term preservation of a partially eclogitized root at the base of the crust and similar to that inferred beneath the western HKTO. Crustal structure in the northern THO strongly resembles the lower crustal structure of the HKTO, suggesting that Moho depths may have reached 60–70 km when the orogen was active. A prominent midcrustal discontinuity beneath the central Grenville Province and changes in the patterns of seismic anisotropy in the THO crust beneath Hudson Bay provide geophysical evidence that lower crustal flow likely played a role in the evolution of both orogens, similar to that inferred beneath the present‐day HKTO. The seismic evidence from Canada supports the notion of tectonic uniformitarianism, at least as far back as the Paleoproterozoic.

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“…Darbyshire (2003), F. Darbyshire et al (2007), D. W. Eaton et al (1995), D. W. Eaton and Hynes (2000), D. W. Eaton et al (2006), Funck and Louden (1998), Funck, Louden, & Reid (2000, Funck, Louden, Wardle, et al (2000), Funck et al (2001Funck et al ( , 2008, Gilligan et al (2016), A. Green et al (1988, Hammer et al (2010), Hynes et al (2000), H. Jackson et al (1998), Kao et al (2013), Levin et al (2017), Ludden and Hynes (2000), Martignole et al (2000), Martignole and Calvert (1996), Mereu (2000), Musacchio and Mooney (2002), Musacchio et al (2004), Németh et al (2005), Owens (1987), Pawlak et al (2011), Petrescu et al (2016, Postlethwaite et al (2014), Rondenay et al (2000), Shen and Ritzwoller (2016), D. Snyder et al (2013), D. B. Snyder et al (2015, Thompson et al (2010Thompson et al ( , 2015, Vervaet and Darbyshire (2021), D. White et al (2000White et al ( , 2005, Winardhi and Mereu (1997); Zelt and Ellis (1999) • Derived data-The 1D dispersion curves compiled for the study region and used as input to the Litmo...…”

Section: Data Availability Statementmentioning

confidence: 99%

“…(2015), Thompson et al. (2010, 2015), Vervaet and Darbyshire (2021), D. White et al. (2000, 2005), Winardhi and Mereu (1997); Zelt and Ellis (1999), H. Zhang et al.…”

Section: Data Availability Statementmentioning

confidence: 99%

Thermochemical Structure of the Superior Craton and Environs: Implications for the Evolution and Preservation of Cratonic Lithosphere

Dave,

Darbyshire,

Afonso

et al. 2024

Geochem Geophys Geosyst

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The Archean Superior craton was formed by the assemblage of continental and oceanic terranes at ∼2.6 Ga. The craton is surrounded by multiple Proterozoic mobile belts, including the Paleoproterozoic Trans‐Hudson Orogen which brought together the Superior and Rae/Hearne cratons at ∼1.9–1.8 Ga. Despite numerous studies on Precambrian lithospheric formation and evolution, the deep thermochemical structure of the Superior craton and its surroundings remains poorly understood. Here we investigate the upper mantle beneath the region from the surface to 400 km depth by jointly inverting Rayleigh wave phase velocity dispersion data, elevation, geoid height and surface heat flow, using a probabilistic inversion to obtain a (pseudo‐)3D model of composition, density and temperature. The lithospheric structure is dominated by thick cratonic roots (>300 km) beneath the eastern and western arms of the Superior craton, with a chemically depleted signature (Mg# > 92.5), consistent with independent results from mantle xenoliths. Beneath the surrounding Proterozoic and Phanerozoic orogens, the Mid‐continent Rift and Hudson Strait, we observe a relatively thinner lithosphere and more fertile composition, indicating that these regions have undergone lithospheric modification and erosion. Our model supports the hypothesis that the core of the Superior craton is well‐preserved and has evaded lithospheric destruction and refertilization. We propose three factors playing a critical role in the craton's stability: (a) the presence of a mid‐lithospheric discontinuity, (b) the correct isopycnic conditions to sustain a strength contrast between the craton and the surrounding mantle, and (c) the presence of weaker mobile belts around the craton.

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CAN‐HK: An a Priori Crustal Model for the Canadian Shield

Cited by 7 publications

References 39 publications

Precambrian Plate Tectonics in Northern Hudson Bay: Evidence From P and S Wave Seismic Tomography and Analysis of Source Side Effects in Relative Arrival‐Time Data Sets

Precambrian Plate Tectonics in Northern Hudson Bay: Evidence From P and S Wave Seismic Tomography and Analysis of Source Side Effects in Relative Arrival‐Time Data Sets

A tale of two orogens: Crustal processes in the Proterozoic Trans‐Hudson and Grenville Orogens, eastern Canada

Thermochemical Structure of the Superior Craton and Environs: Implications for the Evolution and Preservation of Cratonic Lithosphere

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