Application of section-balancing techniques to deep seismic reflection data from offshore eastern Canada: preliminary observations: Addendum

1991 ◽  
Vol 28 (1) ◽  
pp. 154-154
Author(s):  
M. C. Dentith ◽  
J. Hall
Keyword(s):  
Seismic Reflection ◽  
Eastern Canada ◽  
Seismic Reflection Data ◽  
Deep Seismic Reflection ◽  
Reflection Data

Application of section-balancing techniques to deep seismic reflection data from offshore eastern Canada: preliminary observations

1990 ◽  
Vol 27 (4) ◽  
pp. 494-500 ◽  
Author(s):  
M. C. Dentith ◽  
J. Hall
Keyword(s):  
Seismic Reflection ◽  
Hanging Wall ◽  
Shear Zones ◽  
Ductile Deformation ◽  
Eastern Canada ◽  
Seismic Reflection Data ◽  
Deep Seismic Reflection ◽  
Grand Banks ◽  
Jeanne D'arc Basin ◽  
Reflection Data

The application of section-balancing techniques to the analysis of deep seismic sections requires account be taken of isostasy and ductile-deformation processes. Structures imaged by deep seismic reflection profiling across the southern Grand Banks, offshore eastern Canada, are analyzed in this way. Correlations of dipping events in the deep crust, interpreted as shear zones, with faults recognized in the shallow part of the section are tested by attempting to restore the sections to their undeformed state by reversing the displacements on the faults. This process tests the geometric compatibility of the interpreted fault and the structures in its hanging wall. Our models suggest that the faults bounding the Whale and Horseshoe basins detach at the Mohorovičić discontinuity. In contrast, the fault bounding the Jeanne d'Arc Basin detaches within the lower crust.

Deep crustal structure beneath a rifted basin: results from seismic refraction measurements across the Jeanne d'Arc Basin, offshore eastern Canada

1990 ◽  
Vol 27 (11) ◽  
pp. 1462-1471 ◽  
Author(s):  
I. D. Reid ◽  
C. E. Keen
Keyword(s):  
Crustal Structure ◽  
Lower Crust ◽  
Seismic Reflection ◽  
Seismic Refraction ◽  
Eastern Canada ◽  
Seismic Reflection Data ◽  
Deep Seismic Reflection ◽  
Jeanne D'arc Basin ◽  
Reflection Data ◽  
Jeanne D'arc

A crustal seismic refraction experiment was conducted across the south Jeanne d'Arc Basin, one of the rifted sedimentary basins on the Grand Banks, offshore eastern Canada, that developed in Mesozoic time in response to extension and rifting between the North American plate and the African, Iberian, and European plates. The primary objective of this experiment, which was carried out to correlate with an existing deep seismic reflection profile, was to delineate the deep crustal geometry below the basin. Ten ocean-bottom seismometers were deployed across the basin and recorded signals from a large air-gun array. The results show that the crust is primarily composed of two layers, with velocities of 5.8–6.1 and 7.2 km/s, respectively. There is very little relief on the Moho across the basin, with only a 2 km step, from a depth of 37 to 35 km, occurring west of the basin. There is, however, considerable complexity of crustal structure, particularly near Moho depths. These results are valuable when used in conjunction with other data in the region, in particular gravity and deep seismic reflection data. The seismic reflection and refraction data sets together give a fairly complete picture of crustal geometry in the crust. The flat Moho below the basin is compatible with the detachment of the major basin-bounding fault in the lower crust or at the Moho, as seen on the reflection data. The 7.2 km/s layer is not restricted to the zone of Mesozoic crustal extension below the basin, but occurs also below relatively unextended parts of the crust. This layer may represent basaltic intrusion or underplating during a rifting event. It may also correspond to the reflective lower crust observed on the deep seismic reflection data. These results provide strong constraints on models describing the origin and evolution of this and other rifted basins.

Crustal Structure of Turkey from Aeromagnetic, Gravity and Deep Seismic Reflection Data

2012 ◽  
Vol 33 (5) ◽  
pp. 869-885 ◽  
Author(s):  
Abdullah Ates ◽  
Funda Bilim ◽  
Aydin Buyuksarac ◽  
Attila Aydemir ◽  
Ozcan Bektas ◽  
...  
Keyword(s):  
Crustal Structure ◽  
Seismic Reflection ◽  
Seismic Reflection Data ◽  
Deep Seismic Reflection ◽  
Reflection Data

scholarly journals Improved Interpretation of Deep Seismic Reflection Data in Areas of Complex Geology Through Integration With Passive Seismic Data Sets

2018 ◽  
Vol 123 (12) ◽  
pp. 10,810-10,830
Author(s):  
Michael Dentith ◽  
Huaiyu Yuan ◽  
Ruth Elaine Murdie ◽  
Perla Pina-Varas ◽  
Simon P. Johnson ◽  
...  
Keyword(s):  
Seismic Data ◽  
Seismic Reflection ◽  
Data Sets ◽  
Seismic Reflection Data ◽  
Deep Seismic Reflection ◽  
Reflection Data ◽  
Passive Seismic ◽  
Complex Geology

scholarly journals Variation of Moho Depth across Bangong-Nujiang Suture in Central Tibet—Results from Deep Seismic Reflection Data

2015 ◽  
Vol 06 (08) ◽  
pp. 821-830 ◽  
Author(s):  
Zhanwu Lu ◽  
Rui Gao ◽  
Hongqiang Li ◽  
Wenhui Li ◽  
Xiaosong Xiong
Keyword(s):  
Seismic Reflection ◽  
Moho Depth ◽  
Seismic Reflection Data ◽  
Deep Seismic Reflection ◽  
Reflection Data ◽  
Central Tibet

Lower crustal heterogeneity beneath Britain from deep seismic reflection data

1989 ◽  
Vol 146 (4) ◽  
pp. 617-630 ◽  
Author(s):  
R. A. CHADWICK ◽  
T. C. PHARAOH ◽  
N. J. P. SMITH
Keyword(s):  
Seismic Reflection ◽  
Seismic Reflection Data ◽  
Deep Seismic Reflection ◽  
Reflection Data ◽  
Crustal Heterogeneity ◽  
Lower Crustal

Deep seismic reflection data of EDGE U.S. mid-Atlantic continental-margin experiment: Implications for Appalachian sutures and Mesozoic rifting and magmatic underplating

Geology ◽  
1993 ◽  
Vol 21 (6) ◽  
pp. 563 ◽  
Author(s):  
Robert E. Sheridan ◽  
Douglas L. Musser ◽  
Lynn Glover, III ◽  
Manik Talwani ◽  
John I. Ewing ◽  
...  
Keyword(s):  
Continental Margin ◽  
Seismic Reflection ◽  
Seismic Reflection Data ◽  
Deep Seismic Reflection ◽  
Reflection Data ◽  
Magmatic Underplating

Mantle degassing in a collisional zone: Subduction types A & B in the Central Mediterranean

2020 ◽  
Author(s):  
Antonio Caracausi ◽  
Attilio Sulli ◽  
Maurizio Gasparo Morticelli ◽  
Marco Pantina ◽  
Paolo Censi ◽  
...  
Keyword(s):  
Seismic Reflection ◽  
Mantle Wedge ◽  
Geochemical Data ◽  
Etna Volcano ◽  
Central Mediterranean ◽  
Seismic Reflection Data ◽  
Deep Seismic Reflection ◽  
Reflection Data ◽  
Mantle Fluids ◽  
Mantle Volatiles

<p>The central Mediterranean is a very complex area constituted by a puzzle of different lithosphere segments, whose geological evolution is controlled by the interaction between the European and African plates. Within this geological domain, the northern Sicily continental margin and adjacent coastal belt represent a link between the Sicilian chain and the Tyrrhenian extensional (back-arc) area in the north-south direction, whereas in the east-west direction a transition from a subduction type B (Ionian-Tyrrhenian) to a continental collisional system, subduction type A, (Sicilian-Maghrebian Chain) is recognized.</p><p>The structure of the lithosphere in this area is matter of a strong debate. Most uncertainties on the geologic evolution of the boundary between the European and African plate at depth rise from the lack, up to now, of constraints and clear evidence of geometry of the lithosphere down to the crust-mantle interface.</p><p>In order to investigate the regional crust-mantle tectonics, here we discuss recent deep seismic reflection data, gravimetric modelling, the regional fluid geochemistry coupled to the seismicity that clearly indicate presence, along this sector of the Central Mediterranean, of a hot mantle-wedging at about 28 km of depth. This wedge lies just below a thick-skinned deformed belt cut by a dense system of faults down to the Mohorovicic discontinuity.</p><p>We also discuss new geochemical data in mineralization (fluorite) of hydrothermal deposits along the main regional faults above the mantle wedge. The mineralization is strongly enriched in saline fluid inclusions that allowed high precision analyses of the trapped volatiles (H<sub>2</sub>O, CO<sub>2</sub> and noble gases).</p><p> Notwithstanding the region is far from any evidence of volcanism (Etna volcano and Aeolian Islands are in about 80km), the new geochemical data highlight the presence of mantle-derived volatiles that degas through the crust (e.g., He isotopes, up to 1.4Ra, Ra is the He isotopic ratio in atmosphere). An excess of heat sourced from the mantle characterizes the region. This is a rare case of occurrence of mantle volatiles together with heat in a collisional system.</p><p>The active regional seismicity indicates that the mantle fluids move from the mantle wedge to the surface, hence across the ductile crust that could be thought as a barrier to the advective transfer of fluids because of its low permeability on long time scales. Here we reconstruct the deep faults by the deep seismic reflection data that works as a network of pathways that actively sustains the advective transfer of the mantle fluids through the entire continental crust.     </p><p>Finally, the new geochemical data strongly supports that 1) the mantle wedge and possible associated magmatic intrusions as the source of the mantle volatiles outgassing in the region. A comparison of the noble gases isotopic signature of fluids coming from the mantle wedge and those emitted from the Mt Etna volcano furnish new constrain on the mantle composition below the central Mediterranean getting new constrains to the processes that controlled the geodynamic evolution of the central Mediterranean (i.e., delamination processes).</p>

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