The evolution of the avalonian plate

Rast, N.; Skehan, James W.

doi:10.1016/0040-1951(83)90191-9

Cited by 98 publications

(50 citation statements)

References 72 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Instead, the pre-600 Ma quartzites and carbonates of The Thoroughfare and Kent Island formations (and correlative Green Head Group on the New Brunswick mainland) likely were deposited along the margin of a Precambrian ocean basin associated with the breakup of Rodinia around 780 Ma (Rast and Skehan 1983;Nance 1986bNance , 1987Nance et al 2002). Anorthositic rocks of the Lower Coverdale complex (dated at 976 +8/-7 Ma), buried beneath Carboniferous cover in southeastern New Brunswick (Tesfai 2011) may represent a remnant of basement rocks rifted from the southeastern (present-day coordinates) passive margin of the proposed Precambrian ocean.…”

Section: Tectonic Evolution Of the Grand Manan Terranementioning

confidence: 99%

The Grand Manan Terrane of New Brunswick: Tectonostratigraphy and Relationship to the Gondwanan Margin of the Iapetus Ocean

Fyffe

2014

View full text Add to dashboard Cite

Recently gathered stratigraphic and U–Pb geochronological data indicate that the pre-Triassic rocks of the Grand Manan Terrane on the eastern side of Grand Manan Island can be divided into: (1) Middle Neoproterozoic (late Cryogenian) quartzose and carbonate sedimentary sequences (The Thoroughfare and Kent Island formations); (2) a Late Neoproterozoic (early Ediacaran) volcanic-arc sequence (Ingalls Head Formation); and (3) Late Neoproterozioc (mid- Ediacaran) to earliest Cambrian (early Terreneuvian) sedimentary and volcanic-arc sequences (Great Duck Island, Flagg Cove, Ross Island, North Head, Priest Cove, and Long Pond Bay formations). A comparison to Precambrian terranes on the New Brunswick mainland (Brookville and New River terranes) and in adjacent Maine (Islesboro Terrane) suggests that the sedimentary and volcanic sequences of the Grand Manan Terrane were deposited on the continental margin of a Precambrian ocean basin that opened during the breakup of Rodinia in the Middle Neoproterozoic (Cryogenian) and closed by the Early Cambrian (Terreneuvian) with the final assembling of Gondwana. Rifting associated with the initial opening of the Paleozoic Iapetus Ocean began in the Late Neoproterozoic (late Ediacaran) and so overlapped in time with the closing of the Precambrian Gondwanan ocean. The southeastern margin of the Iapetus Ocean is defined by thick sequences of quartz-rich Cambrian sediments (within the St. Croix and Miramichi terranes of New Brunswick) that were largely derived from recycling of Precambrian passive-margin sedimentary rocks preserved in the Grand Manan and Brookville terranes of New Brunswick and in the Islesboro Terrane of Maine. These Precambrian terranes are interpreted to represent dextrally displaced basement remnants of the Gondwanan continental margin of Iapetus, consistent with the model of a two-sided Appalachian system proposed by Hank Williams in 1964 based on his work in Newfoundland.SOMMAIREDes données stratigraphiques et géochronologiques U–Pb obtenues récemment indiquent que les roches prétriasiques du terrane de Grand Manan du côté est de l’île Grand Manan peuvent être répartis en: 1) séquences sédimentaires quartzeuses et carbonatées du Néoprotérozoïque moyen (Cryogénien tardif) (formations de Thoroughfare et de Kent Island); 2) séquence d’arc volcanique du Néoprotérozoïque tardif (Édiacarien précoce) (formation d’Ingalls Head); 3) séquences sédimentaires et d’arc volcanique du Néoprotérozoïque tardif (milieu de l’Édiacarien) au tout début du Cambrien (Terreneuvien précoce) (formations de Great Duck Island, Flagg Cove, Ross Island, North Head, Priest Cove et Long Pond Bay). Une comparaison avec des terranes du Précambrien dans la partie continentale du Nouveau-Brunswick (terranes de Brookville et New River) et dans le Maine adjacent (terrane d’Islesboro) semble indiquer que les séquences sédimentaires et volcaniques du terrane de Grand Manan se sont déposées sur la marge continentale d’un bassin océanique précambrien qui s’est ouvert durant la fracturation de la Rodinia au Néoprotérozoïque moyen (Cryogénien) et s’est fermé au Cambrien précoce (Terreneuvien) avec l’assemblage final du Gondwana. La distension continentale associée à l’ouverture initiale de l’océan Iapetus au Paléozoïque a commencé au Néoprotérozoïque tardif (Édiacarien tardif) et a donc partiellement coïncidé avec la fermeture de l’océan précambrien du Gondwana. La marge sud-est de l’océan Iapetus est définie par d’épaisses séquences de sédiments cambriens riches en quartz (dans les terranes de St. Croix et de Miramichi du Nouveau-Brunswick) issus en grande partie du recyclage de roches sédimentaires de la marge continentale passive du Précambrien préservées dans les terranes de Grand Manan et de Brookville au Nouveau-Brunswick et dans le terrane d’Islesboro dans le Maine. Ces terranes précambriens sont interprétés comme la représentation de vestiges, ayant subi un déplacement dextre, du socle de la marge continentale gondwanienne de l’océan Iapetus, ce qui concorde avec le modèle d’un système appalachien à deux côtés proposé par Hank Williams en 1964 sur la base de ses travaux à Terre-Neuve.

show abstract

Section: Tectonic Evolution Of the Grand Manan Terranementioning

confidence: 99%

The Grand Manan Terrane of New Brunswick: Tectonostratigraphy and Relationship to the Gondwanan Margin of the Iapetus Ocean

Fyffe

2014

View full text Add to dashboard Cite

show abstract

“…Zwart and Dornsiepen (1978), CognØ andWright (1980), andZiegler (1984) derived pre-Variscan units from the former Proterozoic Europe-African Block, and such basement relics are assumed to be part of Avalonia (e.g. Rast and Skehan 1983;Skehan and . It is not the scope of this paper to recall the complex evolution of these oldest elements which either appear as low-grade or as polymetamorphic domains (pan-African/Cadomian orogeny), and for which the relationship between Cadomian basement areas and Neoproterozoic to Early Palaeozoic sedimentary cover have been the subject of extensive research.…”

Section: Cadomian Basementmentioning

confidence: 99%

Organization of pre-Variscan basement areas at the north-Gondwanan margin

et al. 2001

View full text Add to dashboard Cite

show abstract

“…SMITH (1978) inferred a Late Hadrynian age for this deformation which can be correlated with similar deformation in other parts of the Avalon Zone (STRONG, 1979). Erosion apparently followed immediately the period of deformation (RAST et al, 1976).…”

Section: Geologic Settingmentioning

confidence: 66%

“…It is underlain unconformably by a crystalline complex of probable Archean age (WEEKS, 1954;MURPHY, 1977). The Fourchu Group was correlated with similar volcanosedimentary units in eastern Newfoundland and southern New Brunswick (WEEKS, 1954;RAST et al, 1976;O'BRIEN et al, 1983) which gave radiometric ages (Rb/Sr) in the -630 to -600 Ma range. Deformation is characterized by close folds and an associated penetrative axial planar deformation (MURPHY, 1977).…”

Section: Geologic Settingmentioning

confidence: 94%

“…The tectonic models include volcanic island arc (HUGHES and BRUCKNER, 1972), ensialic island arc (RAST et al, 1976), subduction and Basin and Range type rifting (PAPEZIK, 1972;SCHENK, 1978), continental extension and rifting (RANKIN, 1976), transitional tectonic regime (KING, 1982) resulting from continental margin orogenesis (RAST et al, 1976) and intraplate orogenesis (STRONG et al, 1978), Pan-African terrane predating the opening of an Early Paleozoic proto-Atlantic ocean distinct geological province or "suspect terrane" (WILLIAMS and HATCHER, 1982) moving independently from other Atlantic borderlands.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Paleomagnetism of Late Hadrynian Fourchu gabbro, southern Cape Breton Island, Nova Scotia.

Séguin

Rao

Deutsch

1991

J. geomagn. geoelec

View full text Add to dashboard Cite

A paleomagnetic study was carried out on three gabbroic intrusives in the Avalonian terrane of southeastern Cape Breton Island. Thirty five samples (96 specimens) from seven sites were collected for this purpose. Thermal and/or alternating field treatments were performed. Four components of magnetization were detected. One component coincides with the present Earth's field direction. A second component (A) oriented south-southeast with shallow to intermediate inclination (165,+41) is interpreted as representing a Siluro-Devonian overprint. A third component (B) yields a mean direction to the southeast and an intermediate inclination (147,-54). This component is not observed in North American rock units of Devonian age or younger; it is thus bracketed in the Early Devonian-Late Hadrynian interval. Based on magnetic properties, mineralogical and geological grounds, an Ordovician-Cambrian age of acquisition is attributed to this component of magnetization. A fourth component characterized by a low unblocking temperature and median destructive field has a mean direction to the northeast and an intermediate inclination (54,+47). This uncommon direction is inferred to represent an incompletely isolated magnetization. Compaged to low southern paleolatitudes for the Late Hadrynian period of cratonic North America, the paleolatitudes of the Avalonian terrane are slightly higher but this is not really significant. A sea at the most 1000km wide may have separated North America and Avalon at that time. A comparison of the paleolatitude of Avalon and those of Late Hadrynian Atlantic Ocean borderlands indicates that Avalon could have belonged to North Africa at that time. The Avalonian apparent polar wander path in the Devonian-Late Hadrynian interval still remains uncharted. The collision of Avalon with North America occurred most probably at Middle Devonian time.

show abstract

The evolution of the avalonian plate

Cited by 98 publications

References 72 publications

The Grand Manan Terrane of New Brunswick: Tectonostratigraphy and Relationship to the Gondwanan Margin of the Iapetus Ocean

The Grand Manan Terrane of New Brunswick: Tectonostratigraphy and Relationship to the Gondwanan Margin of the Iapetus Ocean

Organization of pre-Variscan basement areas at the north-Gondwanan margin

Paleomagnetism of Late Hadrynian Fourchu gabbro, southern Cape Breton Island, Nova Scotia.

Contact Info

Product

Resources

About