Middle Neoproterozoic (&lt;750 Ma) to Early Ordovician Sedimentation along the Laurentian Margin of Iapetus

Strachan, R. A.; Prave, Anthony R.; Holdsworth, R. E.

doi:10.1002/9781118274064.ch5

Cited by 4 publications

(5 citation statements)

References 12 publications

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“…3). Strachan & Holdsworth (2000) suggested that the foreland succession and the upper parts of the Southern Highland Group and the Highland Border Complex represent, respectively, shallower and deeper parts of the same passive margin basin. Detrital zircon data from the Ardvreck Group have so far been published only from the Eriboll Formation (Cawood et al 2007b).…”

Section: Geology Of the Cambro-ordovician Succession On The Laurentiamentioning

confidence: 98%

Provenance of the Highland Border Complex: constraints on Laurentian margin accretion in the Scottish Caledonides

Cawood

Merle

Strachan

et al. 2012

JGS

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Section: Geology Of the Cambro-ordovician Succession On The Laurentiamentioning

confidence: 98%

Provenance of the Highland Border Complex: constraints on Laurentian margin accretion in the Scottish Caledonides

Cawood

Merle

Strachan

et al. 2012

JGS

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“…1A, e.g., James et al, 1989;Waldron & van Staal, 2001); the northern continuation of the Humber passive margin into the southern Caledonides is demonstrated by broadly equivalent rock units in Ireland and Scotland (e.g., upper Dalradian Supergroup: Prave et al, 2023;Strachan & Holdsworth, 2000). In western Newfoundland, ca.…”

Section: Ediacaran To Cambrian Stratigraphymentioning

confidence: 99%

“…Metasedimentary and metaigneous rocks of the Argyll and Southern Highland groups and their equivalents comprise the upper parts of the Dalradian Supergroup and record the Ediacaran to early Cambrian tectonic evolution of the Scotland and Ireland sectors of eastern Laurentia (e.g., Prave et al, 2023;Strachan & Holdsworth, 2000). The plate tectonic setting and depositional ages of these rocks are generally constrained by: (1) 604 ± 7 Ma and 612 ± 19 Ma syn-depositional barite deposits associated with upper Argyll Group mafic volcanic rocks (Easdale subgroup, Moles & Selby, 2023); (2) 595 ± 4 Ma (Halliday et al, 1989) and 601 ± 4 Ma (Dempster et al, 2002) zircon U-Pb ages for intrusive and tuffaceous units in the upper Argyll Group, respectively (e.g., Tayvallich volcanics); (3) correlation between some upper Argyll Group rocks and ca.…”

Section: Scotland and Irelandmentioning

confidence: 99%

Late Ediacaran to Early Cambrian Breakup Sequences and Establishment of the Eastern Laurentian Passive Margin, Newfoundland, Canada

Soukup,

Beranek,

Lode

et al. 2024

American Journal of Science

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Sediment provenance studies were conducted to constrain the establishment of the eastern Laurentian or Humber passive margin in Newfoundland, Canada, and examine models for the opening of the Iapetus Ocean and Humber Seaway. Ediacaran to Cambrian Series 2 strata of the lower Labrador and Curling groups contain garnet, muscovite, and feldspar, and yield 1000–1500 Ma detrital zircon grains that reflect local derivation from Grenville Province basement rocks during regional extensional deformation. Cambrian Series 2 to early Miaolingian units of the upper Labrador and Curling groups are quartz-rich and characterized by 556–586 Ma and 1000–2700 Ma detrital zircon grains that instead reflect continental-scale drainage and transition to passive margin deposition along eastern Laurentia. The geological relationships along the Humber margin are compared with modern analogues in the Newfoundland-west Iberia rift system to propose a magma-poor rift model that includes two breakup sequences which formed in response to isostatic adjustment after the rupture of crust and mantle, respectively. Crustal breakup resulted in an Ediacaran to Cambrian Series 2 breakup sequence that was connected to hyperextension, mantle exhumation, and bimodal magmatism. Mantle breakup likely occurred >20 Myr after first mantle exhumation and resulted in a breakup sequence that is best characterized by Cambrian Series 2 to early Miaolingian strata. The mantle breakup sequence consists of regressive-transgressive cycles that record the transition from breakup to thermal subsidence and was probably driven by the separation of the Dashwoods microcontinent from eastern Laurentia and outboard opening of west Iapetus. The Humber Seaway opened between the Humber margin and Dashwoods and was at least partially underlain by exhumed continental mantle. Our scenarios support hypotheses for equivalent magma-poor rift elements elsewhere in the Caledonian-Appalachian orogen, and we predict that crustal and mantle breakup sequences are exposed in the Scotland-Ireland and Quebec-New England segments of the eastern Laurentian margin.

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“…In the North Mayo tectonic zone, Neoproterozoic strata of the Dalradian Supergroup (Condon and Prave, 2000) are interpreted to record ca. 720-595 Ma passive-margin sedimentation related to the rifting/ breakup of Rodinia (Strachan and Holdsworth, 2000). To the south, continentally derived mélange and dismembered ophiolite (Cambrian-Ordovician Clew Bay Complex; e.g., Dewey and Mange, 1999) combine to form the Northwestern composite terrane (e.g., Murphy et al, 1991).…”

Section: Grampian-taconic Orogenymentioning

confidence: 99%

Orogenic link ∼41°N–46°N: Collisional mountain building and basin closure in the Cordillera of western North America

et al. 2019

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Polyphase structural mapping and mineral age dating across the Salmon River suture zone in west-central Idaho (Riggins region; ∼45°30′N, ∼117°W–116°W) support a late Mesozoic history of penetrative deformation, dynamothermal metamorphism, and intermittent magmatism in response to right-oblique oceanic-continental plate convergence (Farallon–North America). High-strain linear-planar tectonite fabrics are recorded along an unbroken ∼48 km west-to-east transect extending from the Snake River (Wallowa intra-oceanic arc terrane; eastern Blue Mountains Province) over the northern Seven Devils Mountains into the lower Salmon River Canyon (ancestral North America; western Laurentia). Given the temporally overlapping nature (ca. 145–90 Ma) of east-west contraction in the Sevier fold-and-thrust belt (northern Utah–southeast Idaho–southwest Montana segment), we propose that long-term terrane accretion and margin-parallel northward translation in the Cordilleran hinterland (∼41°N–46°N latitude; modern coordinates) drove mid- to upper-crustal shortening >250 km eastward into the foreland region (∼115°W–113°W). During accretion and translation, the progressive transfer of arc assemblages from subducting (Farallon) to structurally overriding (North American) plates was accommodated by displacement along a shallow westward-dipping basal décollement system underlying the Cordilleran orogen. In this context, large-magnitude horizontal shortening of passive continental margin strata was balanced by the addition of buoyant oceanic crust—late Paleozoic to Mesozoic Blue Mountains Province—to the leading edge of western Laurentia. Consistent with orogenic float modeling (mass conservation, balance, and displacement compatibility), diffuse dextral-transpressional deformation across the accretionary boundary (Salmon River suture: Cordilleran hinterland) was kinematically linked to eastward-propagating structures on the continental interior (Sevier thrust belt; Cordilleran foreland). As an alternative to noncollisional convergent margin orogenesis, we propose a collision-related tectonic origin and contractional evolution for central portions of the Sevier belt. Our timing of terrane accretion supports correlation of the Wallowa terrane with Wrangellia (composite arc/plateau assemblage) and implies diachronous south-to-north suturing and basin closure between Idaho and Alaska.

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Middle Neoproterozoic (<750 Ma) to Early Ordovician Sedimentation along the Laurentian Margin of Iapetus

Cited by 4 publications

References 12 publications

Provenance of the Highland Border Complex: constraints on Laurentian margin accretion in the Scottish Caledonides

Provenance of the Highland Border Complex: constraints on Laurentian margin accretion in the Scottish Caledonides

Late Ediacaran to Early Cambrian Breakup Sequences and Establishment of the Eastern Laurentian Passive Margin, Newfoundland, Canada

Orogenic link ∼41°N–46°N: Collisional mountain building and basin closure in the Cordillera of western North America

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