Crustal structure beneath Namche Barwa, eastern Himalayan syntaxis: New insights from three-dimensional magnetotelluric imaging

2017 ◽  
Vol 122 (7) ◽  
pp. 5082-5100 ◽  
Author(s):  
Changhong Lin ◽  
Miao Peng ◽  
Handong Tan ◽  
Zhiqin Xu ◽  
Zhong-Hai Li ◽  
...  
Keyword(s):  
Crustal Structure ◽  
Three Dimensional ◽  
Namche Barwa ◽  
Magnetotelluric Imaging ◽  
Eastern Himalayan Syntaxis

scholarly journals Crustal architecture of a metallogenic belt and ophiolite belt: implications for mineral genesis and emplacement from 3-D electrical resistivity models (Bayankhongor area, Mongolia)

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Matthew J. Comeau ◽  
Michael Becken ◽  
Alexey V. Kuvshinov ◽  
Sodnomsambuu Demberel
Keyword(s):  
Electrical Resistivity ◽  
Crustal Structure ◽  
Three Dimensional ◽  
Suture Zone ◽  
Fault System ◽  
Magnetotelluric Data ◽  
Low Resistivity ◽  
Ophiolite Belt ◽  
Geological Processes ◽  
Metallogenic Belt

AbstractCrustal architecture strongly influences the development and emplacement of mineral zones. In this study, we image the crustal structure beneath a metallogenic belt and its surroundings in the Bayankhongor area of central Mongolia. In this region, an ophiolite belt marks the location of an ancient suture zone, which is presently associated with a reactivated fault system. Nearby, metamorphic and volcanic belts host important mineralization zones and constitute a significant metallogenic belt that includes sources of copper and gold. However, the crustal structure of these features, and their relationships, are poorly studied. We analyze magnetotelluric data acquired across this region and generate three-dimensional electrical resistivity models of the crustal structure, which is found to be locally highly heterogeneous. Because the upper crust (< 25 km) is found to be generally highly resistive (> 1000 Ωm), low-resistivity (< 50 Ωm) features are conspicuous. Anomalous low-resistivity zones are congruent with the suture zone, and ophiolite belt, which is revealed to be a major crustal-scale feature. Furthermore, broadening low-resistivity zones located down-dip from the suture zone suggest that the narrow deformation zone observed at the surface transforms to a wide area in the deeper crust. Other low-resistivity anomalies are spatially associated with the surface expressions of known mineralization zones; thus, their links to deeper crustal structures are imaged. Considering the available evidence, we determine that, in both cases, the low resistivity can be explained by hydrothermal alteration along fossil fluid pathways. This illustrates the pivotal role that crustal fluids play in diverse geological processes, and highlights their inherent link in a unified system, which has implications for models of mineral genesis and emplacement. The results demonstrate that the crustal architecture—including the major crustal boundary—acts as a first‐order control on the location of the metallogenic belt.

Three-dimensional crustal structure beneath the TOR array and effects on teleseismic wavefronts

1999 ◽  
Vol 314 (1-3) ◽  
pp. 309-319 ◽  
Author(s):  
R. Arlitt ◽  
E. Kissling ◽  
J. Ansorge
Keyword(s):  
Crustal Structure ◽  
Three Dimensional

Three-dimensional seismic crustal structure of the Monashee hinterland core complex on the Lithoprobe Southern Canadian Cordillera Transect

1995 ◽  
Vol 32 (10) ◽  
pp. 1531-1540 ◽  
Author(s):  
Kris Vasudevan ◽  
Frederick A. Cook ◽  
Rolf Maier
Keyword(s):  
Crustal Structure ◽  
Complex Geometry ◽  
Three Dimensional ◽  
Canadian Cordillera ◽  
Metamorphic Complex ◽  
Migration Process ◽  
The South ◽  
Core Complex ◽  
South Central ◽  
Early Tertiary

Three-dimensional seismic coverage in an approximately 12 km × 12 km area of the southern Monashee metamorphic complex in the south-central portion of the Canadian Cordillera reveals a complex geometry to the Mesozoic–early Tertiary contractional Monashee décollement. Data were acquired as part of the Lithoprobe Southern Canadian Cordillera Transect where two approximately perpendicular lines intersected on the south flank of the Monashee mountains in the hinterland of the Cordillera. Stacks of traces within 100 m × 100 m bins are nominally 6-fold, but range from zero to 108-fold due to the crooked nature of the lines. Both migrated and unmigrated data have been examined for interpretation, but the highly variable data quality and discontinuous reflectivity cause excessive added noise during the migration process.

Three-dimensional audio-frequency magnetotelluric imaging of Akebasitao granitic intrusions in Western Junggar, NW China

2016 ◽  
Vol 135 ◽  
pp. 288-296 ◽  
Author(s):  
Bo Yang ◽  
Anqi Zhang ◽  
Sheng Zhang ◽  
Ying Liu ◽  
Shengye Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Audio Frequency ◽  
Nw China ◽  
Granitic Intrusions ◽  
Magnetotelluric Imaging
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