Modification of crust and mantle lithosphere beneath the southern part of the eastern North American passive margin

2021 ◽  
Author(s):  
Cong Li ◽  
Haiying Gao
Keyword(s):  
North American ◽  
Passive Margin ◽  
Mantle Lithosphere

scholarly journals Probing crustal and mantle lithosphere origin through Ordovician volcanic rocks along the Iberian passive margin of Gondwana

2008 ◽  
Vol 461 (1-4) ◽  
pp. 166-180 ◽  
Author(s):  
J. Brendan Murphy ◽  
G. Gutiérrez-Alonso ◽  
J. Fernández-Suárez ◽  
James A. Braid
Keyword(s):  
Volcanic Rocks ◽  
Passive Margin ◽  
Mantle Lithosphere

The Lithoprobe trans-continental lithospheric cross sections: imaging the internal structure of the North American continentThis article is one of a series of papers published in this Special Issue on the theme Lithoprobe — parameters, processes, and the evolution of a continent.Lithoprobe Publication 1487.

2010 ◽  
Vol 47 (5) ◽  
pp. 821-857 ◽  
Author(s):  
Philip T.C. Hammer ◽  
Ron M. Clowes ◽  
Fred A. Cook ◽  
Arie J. van der Velden ◽  
Kris Vasudevan
Keyword(s):  
Cross Sections ◽  
North American ◽  
Lithospheric Mantle ◽  
Large Scale ◽  
Passive Margin ◽  
Cascadia Subduction Zone ◽  
American Continent ◽  
North American Continent ◽  
Continental Scale ◽  
The North

Three lithospheric cross sections provide a continental-scale synthesis of more than two decades of coordinated multidisciplinary research during the Canadian Lithoprobe project. The sections are based on seismic reflection and refraction data combined with a broad range of geological, geochemical, geochronological, and geophysical data. The dataset is derived from remnants of nearly every kind of tectonic regime, and the geologic history of the entrained rocks spans the Present to the Mesoarchean. The longest of the three cross sections is located within a 6000 km long Trans-Canada corridor traversing the North American continent at 45°N–55°N. From west to east, the profile crosses the Juan de Fuca ridge and active Cascadia subduction zone, the Cordilleran, Albertan, and Trans-Hudson orogens, the Superior Province, the Midcontinent rift, the Grenville and Appalachian orogens, and the Atlantic passive margin. The two northern cross sections include (i) a 2000 km long corridor in northwestern Canada (54°N–63°N) crossing the Cordilleran, Wopmay, and Slave orogens; and (ii) a 1600 km long corridor in northeastern Canada (52°N–61°N) crossing the New Quebec and Torngat orogens, the Nain craton, and the Makkovik and Grenville orogens. The unprecedented scale of the cross sections illuminates the assembly of the North American continent. Relationships between orogens are emphasized; plate collisions and accretions have sequentially stacked orogen upon orogen such that the older crust forms basement to the next younger. The large-scale perspective of these regional sections highlights the subhorizontal Moho that is indicative of either structural or thermal re-equilibration (or both), as few crustal roots beneath orogens are preserved. In contrast, heterogeneities in the lithospheric mantle suggest that, in certain situations, relict subducted or delaminated lithosphere can remain intact beneath and eventually within cratonic lithospheric mantle.

Cambrian detrital zircon signatures of the northern Cordilleran passive margin, Liard area, Canada: evidence of sediment recycling, non-Laurentian ultimate sources, and basement denudation

2017 ◽  
Vol 54 (6) ◽  
pp. 609-621
Author(s):  
Margot McMechan ◽  
Lisel Currie ◽  
Filippo Ferri ◽  
William Matthews ◽  
Paul O’Sullivan
Keyword(s):  
North American ◽  
Detrital Zircon ◽  
Lower Cambrian ◽  
Probability Distributions ◽  
Detrital Zircons ◽  
Passive Margin ◽  
Early Cambrian ◽  
Middle Cambrian ◽  
Middle Member

Detrital zircon U–Pb age probability distributions for the Cambrian Vizer formation (informal) and Mount Roosevelt Formation (middle member) of the northern Canadian Cordilleran passive margin indicate extensive recycling from ∼1.7 to 1.6 Ga Paleoproterozoic sandstones and Proterozoic and Lower Cambrian strata, respectively. The units have minor or no first cycle input from Laurentian basement. The lower part of the Vizer formation contains North American magmatic gap (1610–1490 Ma) detrital zircons and lacks ultimate Grenvillian sourced grains, indicating that the grains were likely sourced from a nearby Mesoproterozoic basin and have an ultimate non-Laurentian source. Detrital zircon U–Pb ages of 670–640 Ma from the middle member of the Mount Roosevelt Formation indicate associated volcanic clasts were locally sourced, and are not of syn-sedimentary Middle Cambrian age. Provenance of these units was indirectly impacted by the Liard Line basement feature. Detrital zircon U–Pb age probability distributions from the northern Canadian Cordilleran passive margin indicate sediments were sourced from the east in the Early Cambrian (Terreneuvian; Vizer formation and correlatives) and the northeast during Early Cambrian (Series 2) deposition of Sekwi Formation and correlative strata. In the early Middle Cambrian, the middle member of the Mount Roosevelt Formation was primarily locally sourced, whereas the upper member was derived from Laurentian basement to the east and southeast. The change from reworked Paleoproterozoic cover in the Terrenuvian to primary basement sources in the Middle Cambrian suggests significant denudation of the basement occurred southeast of the Liard Line.

Glacially-influenced late Pleistocene stratigraphy of a passive margin: New Jersey's Record of the North American ice sheet

2005 ◽  
Vol 218 (1-4) ◽  
pp. 155-173 ◽  
Author(s):  
John S. Carey ◽  
Robert E. Sheridan ◽  
Gail M. Ashley ◽  
Jane Uptegrove
Keyword(s):  
Late Pleistocene ◽  
North American ◽  
Ice Sheet ◽  
Passive Margin ◽  
The North

scholarly journals Geology, Mantle Tomography, and Inclination Corrected Paleogeographic Trajectories Support Westward Subduction During Cretaceous Orogenesis in the North American Cordillera

2014 ◽  
Vol 41 (2) ◽  
pp. 207 ◽  
Author(s):  
Robert S. Hildebrand
Keyword(s):  
North America ◽  
North American ◽  
Passive Margin ◽  
Canadian Cordillera ◽  
Western North America ◽  
Geological Evidence ◽  
North American Cordillera ◽  
The North ◽  
Independent Verification ◽  
Haute Résolution

Geological evidence, including the presence of two passive margin platforms, juxtaposed and mismatched deformation between North America and more outboard terranes, as well as the lack of rift deposits, suggest that North America was the lower plate during both the Sevier and Laramide events and that subduction dipped westward beneath the Cordilleran Ribbon Continent (Rubia). Terranes within the composite ribbon continent, now present in the Canadian Cordillera, collided with western North America during the 125–105 Ma Sevier event and were transported northward during the ~80–58 Ma Laramide event, which affected the Cordillera from South America to Alaska. New high-resolution mantle tomography beneath North America reveals a huge slab wall that extends vertically for over 1000 km, marks the site of long-lived subduction, and provides independent verification of the westward-dipping subduction model. Other workers analyzed paleogeographic trajectories and concluded that the initial collision took place in Canada at about 160 Ma – a time and place for which there is no deformational thickening on the North American platform – and later farther west where subduction was not likely westward, but eastward. However, by utilizing a meridionally corrected North American paleogeographic trajectory, coupled with the geologically most reasonable location for the initial deformation, the position of western North America with respect to the relict superslab parsimoniously accounts for the timing and extents of both the Sevier and Laramide events. SOMMAIRELes indications géologiques, en particulier la présence de deux marges de plateforme passives, de déformations adjacentes non-conformes entre l’Amérique du Nord et les terranes extérieurs, ainsi que l’absence de gisements de rift, permet de croire que l’Amérique du Nord était la plaque sous-jacente durant les événements de Sevier et de Laramide et que la subduction plongeait vers l’ouest sous le continent rubané de la Cordillères (Rubia).  Les terranes du continent rubané composite, maintenant au sein de la Cordillère canadienne, sont entrés en collision avec l’ouest de l’Amérique du Nord durant l’événement Sevier (125-105 Ma), et ont été transportés vers le nord durant l’événement Laramide (~80–58 Ma), laquelle a affecté la Cordillère, de l’Amérique du Sud à l’Alaska.  Une nouvelle tomographie haute résolution du manteau sous l’Amérique du Nord montre la présence d’un gigantesque mur de plaques vertical qui s’étend sur 1 000 km, marque le site d’une subduction de longue haleine, et offre une validation indépendante du modèle d’une subduction à pendage vers l’ouest.  D’autres chercheurs ont analysé les trajectoires paléogéographiques et conclu que la collision initiale s’est produite au Canada vers 160 Ma – un moment et un endroit sans épaississement par déformation sur la plateforme d’Amérique du Nord – et plus tard plus à l’ouest, là où la subduction n’était vraisemblablement pas vers l’ouest, mais vers l’est.  Cela dit, en considérant une trajectoire paléogéographique de l’Amérique du Nord corrigée longitudinalement, avec la position géologique la plus probable de la déformation initiale, la position de la portion ouest de l’Amérique du Nord par rapport aux restes de la super-plaque explique alors facilement la chronologie et l’étendue des épisodes Sevier et Laramide.

The Eastern North American Margin Community Seismic Experiment: An Amphibious Active‐ and Passive‐Source Dataset

2019 ◽  
Vol 91 (1) ◽  
pp. 533-540 ◽  
Author(s):  
Colton Lynner ◽  
Harm J. A. Van Avendonk ◽  
Anne Bécel ◽  
Gail L. Christeson ◽  
Brandon Dugan ◽  
...  
Keyword(s):  
North American ◽  
Passive Margin ◽  
North American Plate ◽  
Ocean Bottom ◽  
Wide Angle ◽  
Seismic Profiles ◽  
The North ◽  
Seismic Experiment ◽  
Short Period ◽  
Eastern North American Margin

Abstract The eastern North American margin community seismic experiment (ENAM‐CSE) was conceived to target the ENAM Geodynamic Processes at Rifting and Subducting Margins (GeoPRISMS) primary site with a suite of both active‐ and passive‐source seismic data that would shed light on the processes associated with rift initiation and evolution. To fully understand the ENAM, it was necessary to acquire a seismic dataset that was both amphibious, spanning the passive margin from the continental interior onto the oceanic portion of the North American plate, and multiresolution, enabling imaging of the sediments, crust, and mantle lithosphere. The ENAM‐CSE datasets were collected on‐ and offshore of North Carolina and Virginia over a series of cruises and land‐based deployments between April 2014 and June 2015. The passive‐source component of the ENAM‐CSE included 30 broadband ocean‐bottom seismometers (OBSs) and 3 onshore broadband instruments. The broadband stations were deployed contemporaneously with those of the easternmost EarthScope Transportable Array creating a trans‐margin amphibious seismic dataset. The active‐source portion of the ENAM‐CSE included several components: (1) two onshore wide‐angle seismic profiles where explosive shots were recorded on closely spaced geophones; (2) four major offshore wide‐angle seismic profiles acquired with an airgun source and short‐period OBSs (SPOBSs), two of which were extended onland by deployments of short‐period seismometers; (3) marine multichannel seismic (MCS) data acquired along the four lines of SPOBSs and a series of other profiles along and across the margin. During the cruises, magnetic, gravity, and bathymetric data were also collected along all MCS profiles. All of the ENAM‐CSE products were made publicly available shortly after acquisition, ensuring unfettered community access to this unique dataset.

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