scholarly journals Bridging the gap between the foreland and hinterland I: Geochronology and plate tectonic geometry of Ordovician magmatism and terrane accretion on the Laurentian margin of New England

2017 ◽  
Vol 317 (5) ◽  
pp. 515-554 ◽  
Author(s):  
Paul Karabinos ◽  
Francis A. Macdonald ◽  
James L. Crowley
Keyword(s):  
New England ◽  
Plate Tectonic ◽  
Ordovician Magmatism ◽  
Laurentian Margin ◽  
Terrane Accretion

scholarly journals Bridging the gap between the foreland and hinterland II: Geochronology and tectonic setting of Ordovician magmatism and basin formation on the Laurentian margin of New England and Newfoundland

2017 ◽  
Vol 317 (5) ◽  
pp. 555-596 ◽  
Author(s):  
Francis A. Macdonald ◽  
Paul M. Karabinos ◽  
James L. Crowley ◽  
Eben B. Hodgin ◽  
Peter W. Crockford ◽  
...  
Keyword(s):  
New England ◽  
Tectonic Setting ◽  
Basin Formation ◽  
Ordovician Magmatism ◽  
Laurentian Margin

WITHIN-PLATE TECTONIC SETTING OF PALEOZOIC ALKALIC SUITES IN SE NEW ENGLAND, USA: CONSTRAINTS FROM CA-TIMS U-PB ZIRCON GEOCHRONOLOGY AND PALEOMAGNETISM

2016 ◽  
Author(s):  
Margaret D. Thompson ◽  
◽  
Jahandar Ramezani ◽  
Anne M. Grunow
Keyword(s):  
New England ◽  
Tectonic Setting ◽  
Zircon Geochronology ◽  
Plate Tectonic

Ordovician and Silurian metamorphic cooling ages along the Laurentian margin of the Quebec Appalachians: Bridging the gap between New England and Newfoundland

Geology ◽  
1997 ◽  
Vol 25 (7) ◽  
pp. 583 ◽  
Author(s):  
Sébastien Castonguay ◽  
Alain Tremblay ◽  
Gilles Ruffet ◽  
Gilbert Féraud ◽  
Nicolas Pinet ◽  
...  
Keyword(s):  
New England ◽  
Laurentian Margin

scholarly journals Tracking 40 Million Years of Migrating Magmatism across the Idaho Batholith Using Zircon U-Pb Ages and Hf Isotopes from Cretaceous Bentonites

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1011
Author(s):  
Jeffrey S. Hannon ◽  
Craig Dietsch ◽  
Warren D. Huff ◽  
Davidson Garway
Keyword(s):  
Regional Scale ◽  
Temporal Trends ◽  
Volcanic Eruptions ◽  
Mineral Chemistry ◽  
Bighorn Basin ◽  
Convergent Margins ◽  
Icp Ms ◽  
History Of ◽  
Laurentian Margin ◽  
Terrane Accretion

Cretaceous strata preserved in Wyoming contain numerous large bentonite deposits formed from the felsic ash of volcanic eruptions, mainly derived from Idaho batholith magmatism. These bentonites preserve a near-continuous 40 m.y. chronology of volcanism and their whole-rock and mineral chemistry has been used to document igneous processes and reconstruct the history of Idaho magmatism as emplacement migrated across the Laurentian margin. Using LA-ICP-MS, we analyzed the U-Pb ages and Hf isotopic compositions of nearly 700 zircon grains from 44 bentonite beds from the Bighorn Basin, Wyoming. Zircon populations contain magmatic autocrysts and antecrysts which can be linked to the main pulses of the Idaho batholith and xenocrysts ranging from approx. 250 Ma to 1.84 Ga from country rocks and basement source terranes. Initial εHf compositions of Phanerozoic zircons are diverse, with compositions ranging from −26 to nearly +12. Based on temporal trends in zircon ages and geochemistry, four distinct periods of plutonic emplacement are recognized during the Mid- to Late Cretaceous that follow plutonic emplacement across the Laurentian suture zone in western Idaho and into western Montana with the onset of Farallon slab shallowing. Our data demonstrate the utility of using zircons in preserved tephra to track the regional-scale evolution of convergent margins related to terrane accretion and the spatial migration of magmatism related to changes in subduction dynamics.

The Taconian orogeny in southern New England: Nd-isotope evidence against addition of juvenile components

1996 ◽  
Vol 33 (12) ◽  
pp. 1612-1627 ◽  
Author(s):  
B. Bock ◽  
S. M. McLennan ◽  
G. N. Hanson
Keyword(s):  
New England ◽  
Sedimentary Rocks ◽  
Late Ordovician ◽  
Nd Isotope ◽  
Middle Ordovician ◽  
Southern New England ◽  
Isotope Evidence ◽  
Juvenile Crust ◽  
Plutonic Rocks ◽  
Laurentian Margin

Nd-isotope data for pre-Taconian (meta)sedimentary and igneous rocks, syn-Taconian (meta)sedimentary rocks, and Late Ordovician–Silurian plutonic rocks indicate that the Ordovician Taconian orogeny did not add significant amounts of juvenile crust to the Laurentian margin in southern New England. Nd-isotope compositions of Grenvillian crust and Late Proterozoic to Early Cambrian rift sediments range from εNd of −3.1 to −6.6 at 450 Ma. Sedimentary rocks deposited during the Cambrian and the early Middle Ordovician, which represent the drift stage of Laurentia, and earliest Taconian sedimentary rocks show more negative εNd(450 Ma), with a range from −11.7 to −13.3. Sedimentary rocks deposited in response to the Taconian orogeny have uniform εNd(450 Ma) values of about −8. Middle to Late Ordovician and Permian plutonic rocks from southwestern Connecticut have εNd(450 Ma) values of −2 to −5, which indicates that these rocks contain older crustal components. Rocks with juvenile Nd characteristics are the early Paleozoic Maltby Lake Volcanics (εNd(450 Ma) +8) from southwestern Connecticut, and Middle Ordovician igneous samples from the Hawley Formation (εNd(450 Ma) +6 to −0.6) in Massachusetts.

Caledonian transpressional terrane accretion along the Laurentian margin in Co. Mayo, Ireland

1995 ◽  
Vol 152 (5) ◽  
pp. 797-806 ◽  
Author(s):  
D. H. M. HARRIS
Keyword(s):  
Laurentian Margin ◽  
Terrane Accretion

Probing the Structure of the Crust and Mantle Lithosphere beneath the Southern New England Appalachians via the SEISConn Deployment

2020 ◽  
Vol 91 (5) ◽  
pp. 2976-2986 ◽  
Author(s):  
Maureen D. Long ◽  
John C. Aragon
Keyword(s):  
New England ◽  
Seismic Anisotropy ◽  
Imaging Techniques ◽  
Seismic Velocities ◽  
Mantle Lithosphere ◽  
Tectonic Structures ◽  
Lithospheric Deformation ◽  
Continental Breakup ◽  
Southern New England ◽  
Terrane Accretion

Abstract The eastern margin of North America has been affected by a range of fundamental tectonic processes in the geologic past. Major events include the Paleozoic Appalachian orogeny, which culminated in the formation of the supercontinent Pangea, and the breakup of Pangea during the Mesozoic. The southern New England Appalachians exhibit a particularly rich set of geologic and tectonic structures that reflect multiple episodes of subduction and terrane accretion, as well as subsequent continental breakup. It remains poorly known, however, to what extent structures at depth in the crust and lithospheric mantle reflect these processes, and how they relate to the geological architecture at the surface. The Seismic Experiment for Imaging Structure beneath Connecticut (SEISConn) was a deployment of 15 broadband seismometers in a dense linear array across northern Connecticut. The array traversed a number of major tectonic boundaries, sampling across the Laurentian margin in its western portion to the Avalonian terrane at its eastern end. It also crossed the Hartford rift basin in the central portion of the state. The SEISConn stations operated between 2015 and 2019; data from the experiment are archived at the Incorporated Research Institutions for Seismology Data Management Center and will be publicly available beginning in 2021. A suite of imaging techniques is being applied to SEISConn data, with the goal of providing a detailed view of the crust and mantle lithosphere (including discontinuities, seismic velocities, and seismic anisotropy) beneath the southern New England Appalachians. Results from these analyses will inform a host of fundamental scientific questions about the structural evolution of orogens, the processes involved in continental rifting, and the nature of crustal and mantle lithospheric deformation during subduction, terrane accretion, and continental breakup.

Plate tectonic model for the Carboniferous evolution of the New England Fold Belt

1987 ◽  
Vol 34 (2) ◽  
pp. 213-236 ◽  
Author(s):  
C. G. Murray ◽  
C. L. Fergusson ◽  
P. G. Flood ◽  
W. G. Whitaker ◽  
R. J. Korsch
Keyword(s):  
New England ◽  
Plate Tectonic ◽  
Fold Belt ◽  
Tectonic Model

Tectonic evolution and significance of Silurian – Early Devonian hinterland-directed deformation in the internal Humber zone of the southern Quebec Appalachians

2003 ◽  
Vol 40 (2) ◽  
pp. 255-268 ◽  
Author(s):  
Sébastien Castonguay ◽  
Alain Tremblay
Keyword(s):  
New England ◽  
Tectonic Evolution ◽  
Normal Faults ◽  
Early Devonian ◽  
Middle Ordovician ◽  
Tectonic History ◽  
History Of ◽  
Connecticut Valley ◽  
Laurentian Margin ◽  
Nappe Emplacement

In the southern Quebec Appalachians, the early tectonic history of the Laurentian margin (Humber zone) comprises foreland-propagating, northwest-directed thrust faulting, nappe emplacement, and regional prograde metamorphism in response to the obduction of large ophiolitic nappes during the Taconian orogeny. In the internal Humber zone, this event is dated at 462 ± 3 Ma (late Middle Ordovician), which is interpreted to represent the timing of near-peak Taconian metamorphism. Superimposed hinterland-directed structures are accompanied by retrograde metamorphism and consist of back thrusts and normal faults, which respectively delimit the northwestern and southeastern limbs of the Sutton and Notre-Dame mountains anticlinoria, both salient structures of the internal Humber zone of southern Quebec. Geochronologic data on the timing of hinterland-directed deformation vary from 431 to 411 Ma. Two tectonic models are presented and discussed, which may account for the Silurian – Early Devonian evolution of the Laurentian margin: (1) back thrusting and syn- to post-compressional crustal extension in response to the tectonic wedging of basement-cored duplexes inducing delamination of supracrustal rocks; (2) tectonic exhumation of the internal Humber zone by extensional collapse. Evidence for Silurian – Early Devonian extensional tectonism in the Humber zone provides the basement infrastructures necessary for the creation and the onset of sedimentation in the Gaspé Belt basins (e.g., Connecticut Valley – Gaspé synclinorium). Several structural, metamorphic features in the internal Humber zone of the northwestern New England Appalachians yield analogous characteristics with those of southern Quebec and may have shared a similar Silurian – Early Devonian tectonic evolution.

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