The Notre Dame arc and the Taconic orogeny in Newfoundland

Staal, Cees R. van; Whalen, J B; McNicoll, Vicki J.; Pehrsson, S J; Lissenberg, C. Johan; Zagorevski, A; Breemen, O. van; Jenner, George A.

doi:10.1130/2007.1200(26)

Cited by 117 publications

(81 citation statements)

References 112 publications

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“…(Cawood et al 1994) despite the structural, petrological and sedimentological evidence for Ordovician Taconic tectonism (e.g. Dallmeyer 1977;Cawood and Suhr 1992;van Staal et al 2007). Our data on the Birchy Complex, Advocate Complex and the East Pond Metamorphic Suite indicate that the evidence for Taconic orogeny is locally preserved, but is extensively overprinted elsewhere.…”

Section: U-pb Age and Trace Element Geochemistrymentioning

confidence: 54%

“…Since then, radiometric age dating of metamorphic tectonites occurring in the structural wedge developed on the Laurentian margin in Newfoundland have predominantly yielded Silurian Salinic (Cawood et al 1994;Lin et al 2013) and younger ages, which challenge the strong structural, petrological and sedimentological evidence that these rocks were subjected to Ordovician tectonism at an earlier stage (e.g. Dallmeyer 1977;Cawood and Suhr 1992;van Staal et al 2007). This has called into question the intensity and nature of Taconic orogenesis (Cawood et al 1994) and suggested that Taconic suturing may have been incomplete and convergence continued due to subduction driven by trapped oceanic lithosphere along strike.…”

Section: La Péninsule De Baie Verte Dans Lesmentioning

confidence: 99%

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Taconic Metamorphism Preserved in the Baie Verte Peninsula, Newfoundland Appalachians: Geochronological Evidence for Ophiolite Obduction and Subduction and Exhumation of the Leading Edge of the Laurentian (Humber) Margin During Closure of the Taconic Seaway

Castonguay

Staal

Joyce

et al. 2014

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The Baie Verte Peninsula, western Newfoundland Appalachians, preserves evidence for Early to Mid Ordovician closure of the Taconic seaway, which led to obduction of the Baie Verte oceanic tract (BVOT) ophiolites onto the Laurentian (Humber) margin and Taconic orogenesis. The scarcity of Taconic radiometric ages (and predominance of Silurian (Salinic) data) from the Humber margin rocks (down-going plate) has been problematic, calling into question the intensity and existence of Taconic collisional orogenesis. 40Ar/39Ar and in situ U–Pb geochronology was undertaken on metamorphosed units from the Laurentian basement (Mesoproterozoic East Pond Metamorphic Suite), from the ca. 560 Ma Birchy Complex forming the leading edge of the Humber margin, and from the ca. 490 Ma ophiolitic rocks of the BVOT (Advocate Complex) in order to address this question. Our results confirm evidence of Taconic metamorphism along the Humber margin and at the base of the ophiolites. Ages obtained from the structural base of the Advocate Complex (481–465 Ma) are interpreted to reflect the timing of accretion and internal thickening of the ophiolite, whereas data from the underlying Birchy Complex (467–461 Ma) record the underthrusting and exhumation of the leading edge of the Humber margin along a subduction channel, penecontemporaneously with final obduction of the BVOT. A concordant ca. 465 Ma zircon age and REE data obtained from retrogressed eclogite of the East Pond Metamorphic Suite suggest that the parautochthonous Humber margin was locally subducted to eclogite-facies conditions during the Taconic collision and partly exhumed to amphibolite-facies conditions prior to a strong Silurian (Salinic) tectonometamorphic overprint.SOMMAIRELa péninsule de Baie Verte dans les Appalaches de l’ouest de Terre-Neuve a conservé des indices de la fermeture du bras de mer taconique, qui a mené à l’obduction des ophiolites de la bande océanique de Baie Verte (BOBV) sur la marge laurentienne (Humber) et à l’orogénèse taconique. La rareté des âges radiométriques taconiques (et la prédominance des données siluriennes (saliniques)) provenant des roches de la marge de Humber (i.e. la plaque subductée) a été problématique, mettant en question l’intensité et l’existence de la collision orogénique taconique. De la géochronologie 40Ar/39Ar et U–Pb in situ a été réalisée sur des unités métamorphisés provenant du socle laurentien (la Suite Métamorphique d’East Pond d’âge Mésoprotérozoïque), du Complexe de Birchy daté à ca. 560 Ma formant la partie frontale de la marge de Humber, and des roches ophiolitiques de la BOBV (Complexe d’Advocate) datée à ca. 490 Ma afin de confronter ce questionnement. Nos résultats confirment les indices de métamorphisme taconique le long de la marge de Humber et à la base des ophiolites. Les âges obtenus à la base structurale du Complexe d’Advocate (481–465 Ma) sont interprétés comme reflétant la période d’accrétion et d’épaississement interne de l’ophiolite, tandis que les données du Complexe de Birchy sous-jacent (467–461 Ma) enregistrent le sous-charriage et l’exhumation de la partie frontale de la marge de Humber au sein d’un chenal de subduction, de façon pénécontemporaine à l’obduction finale de la BOBV. Un âge concordant de ca. 465 Ma d’un zircon et les données de terres rares provenant d’une éclogite rétromorphosée de la suite métamorphique d’East Pond suggèrent que la marge de Humber parautochtone a été localement subductée à des conditions du faciès éclogitique durant la collision taconique et partiellement exhumée à des conditions du faciès des amphibolites précédant la forte surimposition tectonométamorphique silurienne (salinique).

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Section: U-pb Age and Trace Element Geochemistrymentioning

confidence: 54%

Section: La Péninsule De Baie Verte Dans Lesmentioning

confidence: 99%

Taconic Metamorphism Preserved in the Baie Verte Peninsula, Newfoundland Appalachians: Geochronological Evidence for Ophiolite Obduction and Subduction and Exhumation of the Leading Edge of the Laurentian (Humber) Margin During Closure of the Taconic Seaway

Castonguay

Staal

Joyce

et al. 2014

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“…490 Ma supra-subduction zone ophiolites (Hibbard 1983;Dunning and Krogh 1985;Cawood et al 1996;Skulski et al 2010) of the Baie Verte oceanic tract (Notre Dame subzone) across the Baie Verte -Brompton line to the east (Fig. 5;van Staal et al 2007). The ultramafic rocks in the Birchy Complex vary from brecciated talc-and/or tremolite-bearing serpentinite to listwanite and bright green fuchsite-actinolite/tremolite schist.…”

Section: Newfoundlandmentioning

confidence: 99%

The Ocean – Continent Transition Zones Along the Appalachian – Caledonian Margin of Laurentia: Examples of Large-Scale Hyperextension During the Opening of the Iapetus Ocean

Chew

Staal

2014

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A combination of deep seismic imaging and drilling has demonstrated that the ocean-continent transition (OCT) of present-day, magma-poor, rifted continental margins is a zone of hyperextension characterized by extreme thinning of the continental crust that exhumed the lowermost crust and/or serpentinized continental mantle onto the seafloor. The OCT on present-day margins is difficult to sample, and so much of our knowledge on the detailed nature of OCT sequences comes from obducted, magma-poor OCT ophiolites such as those preserved in the upper portions of the Alpine fold-and-thrust belt. Allochthonous, lens-shaped bodies of ultramafic rock are common in many other ancient orogenic belts, such as the Caledonian – Appalachian orogen, yet their origin and tectonic significance remains uncertain. We summarize the occurrences of potential ancient OCTs within this orogen, commencing with Laurentian margin sequences where an OCT has previously been inferred (the Dalradian Supergroup of Scotland and Ireland and the Birchy Complex of Newfoundland). We then speculate on the origin of isolated occurrences of Alpine-type peridotite within Laurentian margin sequences in Quebec – Vermont and Virginia – North Carolina, focusing on rift-related units of Late Neoproterozoic age (so as to eliminate a Taconic ophiolite origin). A combination of poor exposure and pervasive Taconic deformation means that origin and emplacement of many ultramafic bodies in the Appalachians will remain uncertain. Nevertheless, the common occurrence of OCT-like rocks along the whole length of the Appalachian – Caledonian margin of Laurentia suggests that the opening of the Iapetus Ocean may have been accompanied by hyperextension and the formation of magma-poor margins along many segments.SOMMAIREDes travaux d’imagerie sismique et des forages profonds ont montré que la transition océan-continent (OCT) de marges continentales de divergence pauvre en magma exposée de nos jours, correspond à une zone d’hyper-étirement tectonique caractérisée par un amincissement extrême de la croûte continentale, qui a exhumé sur le fond marin, jusqu’à la tranche la plus profonde de la croûte continentale, voire du manteau continental serpentinisé. Parce qu’on peut difficilement échantillonner l’OCT sur les marges actuelles, une grande partie de notre compréhension des détails de la nature de l’OCT provient d’ophiolites pauvres en magma d’une OCT obduite, comme celles préservées dans les portions supérieures de la bande plissée alpine. Des masses lenticulaires de roches ultramafiques allochtones sont communes dans de nombreuses autres bandes orogéniques anciennes, comme l’orogène Calédonienne-Appalaches, mais leur origine et signification tectonique reste incertaine. Nous présentons un sommaire des occurrences d’OCT potentielles anciennes de cet orogène, en commençant par des séquences de la marge laurentienne, où la présence d’OCT a déjà été déduites (le Supergroupe Dalradien d’Écosse et d'Irlande, et le complexe de Birchy de Terre-Neuve). Nous spéculons ensuite sur l'origine de cas isolés de péridotite de type alpin dans des séquences de marge des Laurentides du Québec-Vermont et de la Virginie-Caroline du Nord, en nous concentrant sur les unités de rift d'âge néoprotérozoïque tardif (pour éviter les ophiolites du Taconique). La conjonction d’affleurements de piètre qualité et de la déformation taconique omniprésente, signifie que l'origine et la mise en place de nombreuses masses ultramafiques dans les Appalaches demeureront incertaines. Néanmoins, la présence fréquente de roches de type OCT tout le long de la marge Calédonnienne-Appalaches de Laurentia suggère que l'ouverture de l'océan Iapetus peut avoir été accompagnée d’hyper-étirement et de la formation de marges pauvres en magma le long de nombreux segments.

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“…During the Taconic Orogeny from ca. 495-450 Ma [18], the allochthonous strata and associated Lower Ordovician ophiolite complexes (e.g., Bay of Islands complex), were thrust up to 100 km west and over the autochthonous rocks [19]. nearshore depositional environments.…”

Section: Geological Settingmentioning

confidence: 99%

The Use of Integrated Fluid Inclusion Studies for Constraining Petroleum Charge History at Parsons Pond, Western Newfoundland, Canada

2017

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This study, based on fluid inclusion petrography, microthermometry and ultraviolet microspectroscopy of inclusion oil, investigates the petroleum charge history at Parsons Pond, western Newfoundland. To address this matter, drill core and cuttings samples of allochthonous and autochthonous strata in the Parson's Pond area were collected from three exploration wells. Fluid inclusions were examined from fragments of calcite and quartz veins, diagenetic cements in sandstone, and in large hydrothermal dolomite and calcite crystals. Primary aqueous inclusions in authigenic sandstone cements indicate that cementation occurred at relatively shallow depths and low temperatures (<50 • C). Hydrocarbon-bearing fluid inclusions (petroleum, wet gas and gas) are generally restricted to calcite and quartz veins, indicating that petroleum and gas migration at Parson's Pond is fracture-controlled. No hydrocarbons were observed in the diagenetic cements of the essentially tight sandstones. Fluid inclusion microthermometry and ultraviolet microspectroscopy indicate the presence of multiple generations of hydrocarbon fluid, ranging in composition from 33 API gravity petroleum to pure CH 4 . Petrographic evidence suggests that hydrocarbons were generated multiple times during progressive burial and heating. In addition, the distribution of hydrocarbon bearing inclusions with depth suggests that deeper levels are gas-prone, with petroleum confined to relatively shallow depths. Although only gas flow was encountered during the drilling of exploration wells at Parson's Pond, the presence of petroleum-bearing fluid inclusions in calcite and quartz veins indicates that the historical production from shallow wells in the Parsons Pond area likely tapped small reservoirs of fractured petroliferous strata.

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The Notre Dame arc and the Taconic orogeny in Newfoundland

Cited by 117 publications

References 112 publications

Taconic Metamorphism Preserved in the Baie Verte Peninsula, Newfoundland Appalachians: Geochronological Evidence for Ophiolite Obduction and Subduction and Exhumation of the Leading Edge of the Laurentian (Humber) Margin During Closure of the Taconic Seaway

Taconic Metamorphism Preserved in the Baie Verte Peninsula, Newfoundland Appalachians: Geochronological Evidence for Ophiolite Obduction and Subduction and Exhumation of the Leading Edge of the Laurentian (Humber) Margin During Closure of the Taconic Seaway

The Ocean – Continent Transition Zones Along the Appalachian – Caledonian Margin of Laurentia: Examples of Large-Scale Hyperextension During the Opening of the Iapetus Ocean

The Use of Integrated Fluid Inclusion Studies for Constraining Petroleum Charge History at Parsons Pond, Western Newfoundland, Canada

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