Major fracture zones of Morocco: The South Atlas and the Transalboran fault systems

1992 ◽  
Vol 81 (1) ◽  
pp. 185-197 ◽  
Author(s):  
Volker Jacobshagen
Keyword(s):  
Fracture Zones ◽  
The South ◽  
Fault Systems

3-D structure below Ävrö Island from high‐resolution reflection seismic studies, southeastern Sweden

Geophysics ◽  
1999 ◽  
Vol 64 (3) ◽  
pp. 662-667 ◽  
Author(s):  
Christopher Juhlin ◽  
Hans Palm
Keyword(s):  
Seismic Reflection ◽  
Fracture Zones ◽  
The South ◽  
North West ◽  
Reflection Seismic ◽  
Site Investigations ◽  
Seismic Reflection Method ◽  
Shot Point ◽  
Crystalline Crust ◽  
A Charge

Two 1-km-long perpendicular seismic reflection lines were acquired on Ävrö Island, southeast Sweden, in October 1996 in order to (1) test the seismic reflection method for future site investigations, (2) map known fracture zones, and (3) add to the Swedish database of reflection seismic studies of the shallow crystalline crust. An east‐west line was shot with 5-m geophone and shot point spacing, and a north‐south line was shot with 10-m geophone and shotpoint spacing. An explosive source with a charge size of 100 g was used along both lines. The data clearly image three major dipping reflectors and one subhorizontal one in the upper 200 ms (600 m). The dipping reflectors (to the south, east, and north‐west) intersect or project to the surface at or close to where surface‐mapped fracture zones exist. The south‐dipping reflector correlates with the top of a heavily fractured interval observed in a borehole (KAV01) at about 400 m. The subhorizontal zone at about 100–200 m correlates with a known fracture zone in the same borehole (KAV01). 3-D effects are apparent in the data, and only where the profiles cross can the true orientation of the reflecting events be determined. To properly orient and locate all events observed on the lines requires acquisition of 3-D data.

The newest structures of the Heraclion peninsula (South-Western Crimea)

2019 ◽  
pp. 8-16
Author(s):  
M. Yu. Promyslova ◽  
G. V. Bryantseva ◽  
L. I. Demina ◽  
N. I. Kosevich
Keyword(s):  
Oceanic Crust ◽  
Coastal Zone ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Fracture Zones ◽  
The South ◽  
South Eastern ◽  
Back Arc ◽  
Geomorphological Analysis

The article presents the results of the structural-geomorphological analysis of the Heraklion peninsula of the South-Western Crimea. The Western, Central and South-Eastern segments are distinguished, differing in density and direction of fracture zones, faults, the nature of the ravine-gulch net, and the structure of the coastal zone. It is shown that neotectonic movements in the upper structural floor are most intensively manifested over the Late Jurassic-Early Cretaceous collisional suture formed when the back-arc basin with the oceanic crust was closed.

scholarly journals Seismic imaging across fault systems in the Abitibi greenstone belt – An analysis of pre- and post-stack migration approaches in the Chibougamau area, Quebec, Canada

2020 ◽  
Author(s):  
Saeid Cheraghi ◽  
Alireza Malehmir ◽  
Mostafa Naghizadeh ◽  
David Snyder ◽  
Lucie Mathieu ◽  
...  
Keyword(s):  
Seismic Reflection ◽  
Seismic Imaging ◽  
Massive Sulfide ◽  
Geological Structure ◽  
The South ◽  
Element Analysis ◽  
Fault Systems ◽  
The North ◽  
Relative Contribution ◽  
Abitibi Subprovince

Abstract. Two high-resolution seismic reflection profiles acquired north and south of Chibougamau, located in the northeast of the Abitibi subprovince of Canada help understand historic volcanic-hosted massive sulfide (VMS) deposits and hydrothermal Cu-Au mineralization found there. Major faults crossed by the profiles include the Barlow fault in the north and the Doda fault and the Guercheville fault in the south, all targets of this study that seeks to determine spatial relationships with known metal endowment in the area. Common-offset DMO corrections and common-offset pre-stack time migrations (PSTM) were considered. Irregularities of the trace midpoint distribution resulting from the crooked geometry of both profiles and their relative contribution to DMO and PSTM method and seismic illumination were assessed in the context of the complex subsurface architecture of the area. To scrutinize this contribution, seismic images were generated for offset ranges of 0–9 km using increments of 3 km. Migration of out-of-plane reflections used cross-dip element analysis to accurately estimate the fault dip. The seismic imaging shows the thickening of the upper crustal rocks near the fault zones along both profiles. In the north seismic reflection section, key geological structure identified include the Barlow fault and two diffraction sets imaged within the fault zone that represent potential targets for future exploration. The south seismic reflection section shows rather a complicated geometry of two fault systems. The Guercheville fault observed as a subhorizontal reflector connects to a steeply dipping reflector. The Doda fault dips subvertical in the shallow crust but as a steeply dipping reflection set at depth. Nearby gold showings suggest that these faults may help channel and concentrate mineralizing fluids.

scholarly journals Seismic imaging across fault systems in the Abitibi greenstone belt – an analysis of pre- and post-stack migration approaches in the Chibougamau area, Quebec, Canada

Solid Earth ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 1143-1164
Author(s):  
Saeid Cheraghi ◽  
Alireza Malehmir ◽  
Mostafa Naghizadeh ◽  
David Snyder ◽  
Lucie Mathieu ◽  
...  
Keyword(s):  
Seismic Reflection ◽  
Seismic Imaging ◽  
Massive Sulfide ◽  
The South ◽  
Element Analysis ◽  
Fault Systems ◽  
The North ◽  
Relative Contribution ◽  
Abitibi Subprovince ◽  
Seismic Reflection Profiles

Abstract. Two high-resolution seismic reflection profiles acquired north and south of Chibougamau, located in the northeast of the Abitibi subprovince of Canada, help understand historic volcanically hosted massive sulfide (VMS) deposits and hydrothermal Cu–Au mineralization found there. Major faults crossed by the profiles include the Barlow fault in the north and the Doda fault and the Guercheville fault in the south, all targets of this study that seeks to determine spatial relationships with a known metal endowment in the area. Common-offset DMO corrections and common-offset pre-stack time migrations (PSTMs) were considered. Irregularities of the trace midpoint distribution resulting from the crooked geometry of both profiles and their relative contribution to the DMO and PSTM methods and seismic illumination were assessed in the context of the complex subsurface architecture of the area. To scrutinize this contribution, seismic images were generated for offset ranges of 0–9 km using increments of 3 km. Migration of out-of-plane reflections used cross-dip element analysis to accurately estimate the fault dip. The seismic imaging shows the thickening of the upper-crustal rocks near the fault zones along both profiles. In the northern seismic reflection section, the key geological structures identified include the Barlow fault and two diffraction sets imaged within the fault zone that represent potential targets for future exploration. The south seismic reflection section shows rather a complicated geometry of two fault systems. The Guercheville fault observed as a subhorizontal reflector connects to a steeply dipping reflector. The Doda fault dips subvertical in the shallow crust but as a steeply dipping reflection set at depth. Nearby gold showings suggest that these faults may help channel and concentrate mineralizing fluids.

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