Mapping the megathrust beneath the northern Gulf of Alaska using wide-angle seismic data

1994 ◽  
Vol 99 (B6) ◽  
pp. 11663-11685 ◽  
Author(s):  
Thomas M. Brocher ◽  
Gary S. Fuis ◽  
Michael A. Fisher ◽  
George Plafker ◽  
Michael J. Moses ◽  
...  
Keyword(s):  
Seismic Data ◽  
Gulf Of Alaska ◽  
Wide Angle

scholarly journals Structure and evolution of the Atlantic passive margins: A review of existing rifting models from wide-angle seismic data and kinematic reconstruction

2021 ◽  
Vol 126 ◽  
pp. 104898
Author(s):  
Youssef Biari ◽  
Frauke Klingelhoefer ◽  
Dieter Franke ◽  
Thomas Funck ◽  
Lies Loncke ◽  
...  
Keyword(s):  
Seismic Data ◽  
Wide Angle ◽  
Passive Margins

scholarly journals Geometry of the Deep Calabrian Subduction (Central Mediterranean Sea) From Wide‐Angle Seismic Data and 3‐D Gravity Modeling

2020 ◽  
Vol 21 (3) ◽  
Author(s):  
David Dellong ◽  
Frauke Klingelhoefer ◽  
Anke Dannowski ◽  
Heidrun Kopp ◽  
Shane Murphy ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Seismic Data ◽  
Gravity Modeling ◽  
Wide Angle ◽  
Central Mediterranean ◽  
Central Mediterranean Sea

Deep structure of the Atlantic margins and neighboring oceanic crust from wide-angle seismic data and plate kinematic reconstructions.

2021 ◽  
Author(s):  
Frauke Klingelhoefer ◽  
Youssef Biari ◽  
Dieter Franke ◽  
Thomas Funck ◽  
Lies Loncke ◽  
...  
Keyword(s):  
Oceanic Crust ◽  
Seismic Data ◽  
Deep Structure ◽  
Volcanic Eruptions ◽  
Wide Angle ◽  
Seismic Profiles ◽  
Initial Rupture ◽  
Mechanisms Of Formation ◽  
Break Up ◽  
Transform Margin

<p>In order to study opening mechanisms and their variation in the Atlantic ocean basins, we compiled existing wide-angle and deep seismic data along conjugate margins and performed plate tectonic reconstructions of the original opening geometries to define conjugate margin pairs. A total of 23 published wide-angle seismic profiles from the different margins of the Atlantic basin were digitized, and reconstructions at break-up and during early stages of opening were performed. Main objectives were to understand how magma-rich and magma-poor margins develop and to define more precisely the role of geologic inheritance (i.e., preexisting structures) in the break-up phase. At magma-poor margins, a phase of tectonic opening without accretion of a typical oceanic crust often follows initial rupture, leading to exhumation of serpentinized upper mantle material. Along volcanic margins the first oceanic crust can be overthickened, and both over- and underlain by volcanic products. The first proto-oceanic crust is often accreted at slow to very slow rates, and is thus of varied thickness, mantle content and volcanic overprint. Accretion of oceanic crust at slow to very slow spreading rates can also be highly asymmetric, so the proto oceanic crust at each side of conjugate margin pairs can differ. Another major aim of this study was to understand the mechanisms of formation and origins of transform marginal plateaus. These are bathymetric highs located at the border of two ocean basins of different ages and are mostly characterized by one or several volcanic phase during their formation. They often form conjugate pairs along a transform margin as it evolves and might have been the last land bridges during breakup, thereby influencing mammal migration and proto-oceanic currents in very young basins. At these plateaus, volcanic eruptions can lead to deposits of (at least in part subaerial) lava flows several km thick, better known by their geophysical signature as seaward dipping reflectors. Continental crust, if present, is heavily modified by volcanic intrusions. These marginal plateaus might form when rifting stops at barriers introduced by the transform margin, leading to the accumulation of heat in the mantle and increased volcanism directly before or after the cessation of rifting.</p>

Lithospheric structure in northwestern Canada from Lithoprobe seismic refraction and related studies: a synthesis

2005 ◽  
Vol 42 (6) ◽  
pp. 1277-1293 ◽  
Author(s):  
Ron M Clowes ◽  
Philip TC Hammer ◽  
Gabriela Fernández-Viejo ◽  
J Kim Welford
Keyword(s):  
Seismic Data ◽  
Seismic Refraction ◽  
Velocity Model ◽  
Wide Angle ◽  
Slave Craton ◽  
Reflection Data ◽  
Western Cordillera ◽  
Thermal Constraints ◽  
Geological Information ◽  
Tectonic Boundaries

The SNORCLE refraction – wide-angle reflection (R/WAR) experiment, SNORE'97, included four individual lines along the three transect corridors. A combination of SNORE'97 results with those from earlier studies permits generation of a 2000 km long lithospheric velocity model that extends from the Archean Slave craton to the present Pacific basin. Using this model and coincident near-vertical incidence (NVI) reflection data and geological information, an interpreted cross section that exemplifies 4 Ga of lithospheric development is generated. The velocity structural models correlate well with the reflection sections and provide additional structural, compositional, and thermal constraints. Geological structures and some faults are defined in the upper crust. At a larger scale, the seismic data identify a variety of orogenic styles ranging from thin- to thick-skinned accretion in the Cordillera and crustal-scale tectonic wedging associated with both Paleoproterozoic and Mesozoic collisions. Models of Poisson's ratio support the NVI interpretation that a thick wedge of cratonic metasediments underlies the eastern accreted Cordilleran terranes. Despite the variety of ages, orogenic styles, and tectono-magmatic deformations that are spanned by the seismic corridors, the Moho remains remarkably flat and shallow (33–36 km) across the majority of the transect. Significant variations only occur at major tectonic boundaries. Laterally variable crustal velocities are consistently slower beneath the Cordillera than beneath the cratonic crust. This is consistent with the high temperatures (800–900 °C) required by the slow upper mantle velocities (7.8–7.9 km/s) observed beneath much of the Cordillera. Heterogeneity of the lithospheric mantle is indicated by wide-angle reflections below the Precambrian domains and the western Cordillera.

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