scholarly journals Crustal structure of the Trans-European suture zone region along POLONAISE'97 seismic profile P4

2003 ◽  
Vol 108 (B11) ◽  
Author(s):  
Marek Grad
Keyword(s):  
Crustal Structure ◽  
Seismic Profile ◽  
Suture Zone

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.

Crustal structure of the Paleozoic Kunlun orogeny from an active-source seismic profile between Moba and Guide in East Tibet, China

2011 ◽  
Vol 19 (4) ◽  
pp. 994-1007 ◽  
Author(s):  
Zhongjie Zhang ◽  
Simon Klemperer ◽  
Zhiming Bai ◽  
Yun Chen ◽  
Jiwen Teng
Keyword(s):  
Crustal Structure ◽  
Seismic Profile ◽  
Active Source

The transition of the East European cratonic lithosphere to that of the Palaeozoic collage of the Trans-European Suture Zone as depicted on the TTZ-South deep seismic profile (SE Poland to NW Ukraine)

2020 ◽  
Author(s):  
Tomasz Janik ◽  
Vitaly Starostenko ◽  
Paweł Aleksandrowski ◽  
Tamara Yegorova ◽  
Wojciech Czuba ◽  
...  
Keyword(s):  
Crustal Structure ◽  
Lower Crust ◽  
Seismic Velocity ◽  
Sedimentary Cover ◽  
Suture Zone ◽  
Crystalline Basement ◽  
Moho Depth ◽  
Crustal Layer ◽  
Velocity Inversion ◽  
East European

&lt;p&gt;Crustal and uppermost mantle structure along the Teisseyre-Tornquist Zone (TTZ)&amp;#160; was explored along the ~550 km long, NW-SE-trending TTZ-South profile, using seismic wide-angle reflection/refraction (WARR) method. The profile line was intended to follow the border between the East European Craton (EEC) and the so called Palaeozoic Platform (PP) of north-central Europe, believed to contain a number of crustal blocks that were accreted to the craton during pre-late Carboniferous times, defining the Trans-European Suture Zone (TESZ).&lt;/p&gt;&lt;p&gt;The seismic velocity model of the TTZ-South profile shows lateral variations in crustal structure. Its Ukrainian segment crosses the interior of the Sarmatian segment of the EEC, where the crystalline basement gradually dips from ~2 km depth in the SE to ~12 km at the Ukrainian-Polish border. This part of the model shows a four-layered crustal structure, with an up to 15 km-thick sedimentary cover, an underlying crystalline upper crust, a 10-15 km-thick middle crust and a ~15 km thick lower crust. In Poland, the profile passes along the TESZ/EEC transition zone of complex crustal structure. The crystalline basement, whose top occurs at depths of 10-17 km, separates the sedimentary cover from the ~10 km thick mid-crustal layer (Vp=6.5-6.6 km/s), which, in turn, overlies a block of 10-15 km thickness with upper crustal velocities (Vp~6.2 km/s). The latter is underlain by a ~10-15 km-thick lower crust. Along most of the model one can see conspicuous velocity inversion zones occuring at various depths. At intersections of the TTZ-South profile with some previous deep seismic profiles (e.g. CEL02, CEL05, CEL14, PANCAKE) such inversions document complex wedging relationships between the EEC and PP crustal units. These may have resulted from tectonic compression and thick-skinned thrusting due to either Neoproterozoic EEC collision with accreting terranes or intense Variscan orogenic events. Five high velocity bodies (HVB; V&lt;sub&gt;p&lt;/sub&gt; = 6.85-7.2 km/s) were detected in the middle and lower crust at 15-37 km depth. The Moho depth varies substantially along the profile. It is at ~42 km depth in the NW and deepens SE-ward to ~50 km at ~685 km. Subsequently, it rises abruptly to ~43 km at the border of the Sarmatian segment of the EEC and sinks again to ~50 km beneath the Lviv Paleozoic trough at ~785 km. From this point until the SE end of the profile, the Moho gently shallows, up to a depth of ~37 km, including a step-like jump of 2 km at ~875 km. Such abrupt Moho steps may be related to crust-scale strike-slip faults. Along the whole profile, sub-Moho velocities are ~8.05-8.1 km/s, and at depths of 57-63 km Vp values reach 8.2-8.25 km/s. Four reflectors/refractors were modelled in the upper mantle at ~57-65 km and ~80 km depths.&lt;/p&gt;

Crustal structure of the Indus–Tsangpo suture zone and its ophiolites in southern Tibet

2015 ◽  
Vol 27 (2) ◽  
pp. 507-524 ◽  
Author(s):  
Zhi-Qin Xu ◽  
Yildirim Dilek ◽  
Jing-Sui Yang ◽  
Feng-Hua Liang ◽  
Fei Liu ◽  
...  
Keyword(s):  
Crustal Structure ◽  
Suture Zone ◽  
Southern Tibet

An Analysis on Deep Crustal Structure Along the Onshore-Offshore Seismic Profile Across the Binghai (Littoral) Fault Zone in Ne South China Sea

2004 ◽  
Vol 47 (5) ◽  
pp. 954-961 ◽  
Author(s):  
Ming-Hui ZHAO ◽  
Xue-Lin QIU ◽  
Chun-Ming YE ◽  
Kan-Yuan XIA ◽  
Ci-Liu HUANG ◽  
...  
Keyword(s):  
South China Sea ◽  
Fault Zone ◽  
South China ◽  
Crustal Structure ◽  
Seismic Profile ◽  
China Sea ◽  
Deep Crustal Structure
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