Tectonic reactivation of transverse basement structures in the Grenville orogen of SW Quebec, Canada: Insights from gravity and aeromagnetic data

Dufréchou, Grégory; Harris, Lyal B.; Corriveau, Louise

doi:10.1016/j.precamres.2013.11.014

Cited by 31 publications

(14 citation statements)

References 110 publications

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“…In this case, the LSZ could correspond to an underlying thrust shear zone, as proposed by Dufréchou et al. () in the W and Martignole and Friedman () in the N of the Morin dome, and the TSZ could correspond to the overlying normal shear zone. The Morin dome is intruded by the Morin anorthosite, which may have facilitated emplacement of the Morin dome due to a significant buoyancy contrast causing diapirism (Martignole, Calvert, Friedman, & Reynolds, 2000).…”

Section: Emplacement Processmentioning

confidence: 59%

“…The Morin dome could have been exhumed by channel flow, which would require a melt-weakened ductile layer bounded by a thrust shear zone below and a normal shear zone above (Godin, Grujic, Law, & Searle, 2006). In this case, the LSZ could correspond to an underlying thrust shear zone, as proposed by Dufr echou et al (2014) in the W and Martignole and Friedman (1998) in the N of the Morin dome, and the TSZ could correspond to the overlying normal shear zone. The Morin dome is intruded by the Morin anorthosite, which may have facilitated emplacement of the Morin dome due to a significant buoyancy contrast causing diapirism (Martignole, Calvert, Friedman, & Reynolds, 2000 (Nadeau & Brouillette, 1995) complicates Integration of local field information in a regional tectonic setting as part of an aeromagnetic study reveals the presence of a double dome and a role for strike-slip tectonics in the creation of regional structures during the exhumation of deep Grenvillian crust.…”

Section: Tectonic Interpretationmentioning

confidence: 99%

“…In the south‐west Grenville Province, inherited deep‐crustal strike‐slip shear zones have been recognized from gravity data (Dufréchou & Harris, ), and Soucy La Roche, Gervais, Tremblay, Crowley, & Ruffet () described the role of regional shear zones in exhuming mid‐crustal rocks during post‐orogenic collapse. Although regional shear zones widely affect the Grenville Province (Dufréchou, Harris, & Corriveau, ; Dufréchou, Harris, Corriveau, & Antonoff, ), their role in the exhumation of deep crustal units and gneiss domes remains generally undocumented. Bedrock is widely masked by vegetal and glacial covers, local observations are generally extrapolated over significant distances, and the interpretations of exhumation processes and associated structures are somewhat uncertain because of the difficulty in linking local observations to a more regional tectonic framework.…”

Section: Introductionmentioning

confidence: 99%

“…In the south-west Grenville Province, inherited deep-crustal strike-slip shear zones have been recognized from gravity data (Dufr echou & Harris, 2013), and Soucy La Roche, Gervais, Tremblay, Crowley, & Ruffet (2015) described the role of regional shear zones in exhuming mid-crustal rocks during post-orogenic collapse. Although regional shear zones widely affect the Grenville Province (Dufr echou, Harris, & Corriveau, 2014;Dufr echou, Harris, Corriveau, & Antonoff, 2015), their role in the exhumation of deep crustal units and gneiss domes remains generally undocumented.…”

Section: Introductionmentioning

confidence: 99%

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Aeromagnetic signature of an exhumed double dome system in the SW Grenville Province (Canada)

Dufréchou

2017

Terra Nova

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Analysis of aeromagnetic data in the Grenville Province reveals the presence of two regional‐scale unmapped structural domes (the Morin and Mékinac‐Taureau domes) with an oval‐shaped magnetic pattern bounded by regional‐scale shear zones and a geometry that is similar to that produced in crustal flow models under extension, which predict two upright domes of foliation (double dome) separated by a steep shear zone. The Mékinac‐Taureau dome, a metamorphic core complex, and the Morin dome may have been exhumed by channel flow. Exhumation occurred by a combination of thrust, normal‐sense and wrench shear zones. The preservation of paragneisses in the Morin dome suggests that it underwent a lesser degree of exhumation than did the Mékinac‐Taureau dome. This study shows how the integration of local field information with magnetic data in a regional tectonic setting can reveal and delineate concealed gneiss domes and highlights a role for strike‐slip tectonics in the creation of regional structures involving the exhumation of deep crust.

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Section: Emplacement Processmentioning

confidence: 59%

Section: Tectonic Interpretationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Aeromagnetic signature of an exhumed double dome system in the SW Grenville Province (Canada)

Dufréchou

2017

Terra Nova

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“…Interestingly, these north-south-striking corridors are coinciding with Geon 11 AMCG suite corridors (Martignole 1996;Indares and Moukhsil 2013). As suggested by Indares and Moukhsil (2013), partly building on Martignole (1996), these extension-related corridors may have comprised deep structures, as documented from southwestern Quebec (Dufréchou et al 2014), allowing later AMCG suites to ascend to mid-crustal levels during Geons 11 and 10 reactivation.…”

Section: Implication At the Scale Of The Orogen For Geons 15 To 10mentioning

confidence: 76%

Pinwarian to Grenvillian magmatic evolution in the central Grenville Province: new constraints from ID–TIMS U–Pb ages and coupled Lu–Hf S–MC–ICP–MS data

et al. 2015

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Understanding the magmatic evolution of the rocks once comprising the hinterland of the Grenville Orogen through their Mesoproterozoic formation is a key to understanding the Grenvillian Orogeny as a whole. In this contribution, we present high-precision isotope dilution thermal ionization mass spectrometry (ID-TIMS) U-Pb and coupled solution multicollector inductively coupled plasma mass spectrometry (S-MC-ICP-MS) Lu-Hf zircon data from magmatic rocks occurring in the allochthonous belt of the Grenville Orogen in the central part of the Grenville Province. We document the presence of a large tract of Pinwarian crust represented by a 1497 ± 5 Ma granitic gneiss, as well as large late Geon 14 to early Geon 13 (1434 +7/−11, 1413 ± 12, 1393 ± 8, 1383 ± 1 Ma) magmatic complexes. One Grenvillian plutonic suite of 1015 ± 2 Ma that cross-cuts the host-rock metamorphic fabric has also been dated. This age provides a minimum age of Ottawan metamorphism in the region. The Hf-isotopic data show that the magmatic rocks of Geons 14 and 13 had mixed mantle and crustal sources compatible with intrusion in a supra-subduction setting as is also supported by the whole-rock geochemical data presented. Emplacement of the magmatic rocks occurred in settings varying from a distal margin arc to a contractional and extensional continental arc. Grenvillian-aged magmatism is more ambiguous, but our data indicate that rocks as young as ca. 1015 Ma may have formed in an ensialic setting.Résumé : La compréhension de l'évolution magmatique des roches qui composaient jadis l'arrière-pays de l'orogène de Grenville durant leur formation au Mésoprotérozoïque constitue la clé pour comprendre l'orogène de Grenville dans son ensemble. Dans cet article, nous présentons des données de grande précision d'analyses par dilution isotopique et spectrométrie de masse à thermoionisation (ID-TIMS) U-Pb et d'analyses isotopiques Lu-Hf, par une combinaison des techniques S-MC-ICP-MS, de zircons provenant de roches magmatiques se trouvant dans la ceinture allochtone de l'orogène de Grenville dans la partie centrale de la Province de Grenville. Nous documentons la présence d'une grande superficie de croûte (Pinwarien) représentée par un gneiss granitique 1497 ± 5 Ma et de vastes complexes magmatiques du géon 14 au début du géon 13 (1434 +7/−11, 1413 ± 12, 1393 ± 8, 1383 ± 1 Ma). Une suite plutonique (Grenville) de 1015 ± 2 Ma qui recoupe de manière transversale la fabrique métamorphique de la roche encaissante a aussi été datée. Cet âge fournit un âge minimum pour le métamorphisme ottavien dans la région. Les données isotopiques Hf montrent que les roches magmatiques des géons 14 et 13 provenaient de sources mélangées dans le manteau et dans la croûte, ce qui est compatible avec une intrusion dans un environnement de suprasubduction et aussi supporté par les données géochimiques sur la roche entière présentées. La mise en place des roches magmatiques a eu lieu dans des environnements variant d'un arc marginal distal à un arc continental de contraction et d'extens...

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Thick‐skinned tectonics within the intracontinental easternmost Atlas foreland‐and‐thrust belt (Tunisia): Meso‐Cenozoic kinematics and implications for regional geodynamics

2017

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The transition zone between western and central Mediterranean domains presents a key area to investigate kinematic interactions within the adjacent orogen systems such as the easternmost Atlas foreland‐and‐thrust belt. Gravity and seismic data revealed a highly structured basement, characterizing a series of structural highs and lows delimited by high‐angle N‐S, E‐W, and NW‐SE extensional faults. This basement architecture is inherited from successive extensional events related to the openings of the Triassic‐Early Cretaceous Tethys oceans (i.e., Alpine Tethys, Ligurian Tethys, and Mesogea). Throughout this period, this mosaic of continental blocks significantly controlled the thickness and facies distributions. Early stages of diapirism took place along these basement faults and allowed maximum subsidence in minibasins revealed by the development of growth strata. In response to the Late Cretaceous‐Eocene shortenings, these extensional faults have been reactivated as trasnpressional shear zones, giving rise to narrow pop‐up structures. In addition, gravity modeling indicates crustal thinning and deep‐rooted faults affecting the crust south of the Zaghouan Thrust and along E‐W transfer zones. From the late Miocene, a drastic change in the stress regime is attributed to the effect of the adjacent Sicily channel on the study area. This promotes crustal thinning, basin subsidence, and channeling up of mantle‐derived helium along lithospheric‐scale weak zones. Our results give rise to new insights into the reactivation of inherited weakness zones of southern Tethys margin in response to the complex interaction between African and Eurasian plates accommodated by subduction, rollback, collision, and slab segmentation.

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Tectonic reactivation of transverse basement structures in the Grenville orogen of SW Quebec, Canada: Insights from gravity and aeromagnetic data

Cited by 31 publications

References 110 publications

Aeromagnetic signature of an exhumed double dome system in the SW Grenville Province (Canada)

Aeromagnetic signature of an exhumed double dome system in the SW Grenville Province (Canada)

Pinwarian to Grenvillian magmatic evolution in the central Grenville Province: new constraints from ID–TIMS U–Pb ages and coupled Lu–Hf S–MC–ICP–MS data

Thick‐skinned tectonics within the intracontinental easternmost Atlas foreland‐and‐thrust belt (Tunisia): Meso‐Cenozoic kinematics and implications for regional geodynamics

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