Mineralogy of the Au-Ag mineralization from the Finsterort and Anton vein system, Štiavnické vrchy Mts. (Slovakia)

2021 ◽  
Vol 29 (2) ◽  
pp. 255-269
Author(s):  
Jozef Vlasáč ◽  
Martin Chovan ◽  
Rastislav Vojtko ◽  
Peter Žitňan ◽  
Tomáš Mikuš
Keyword(s):  
Middle Miocene ◽  
Precious Metals ◽  
Central Zone ◽  
Strike Slip ◽  
Normal Faults ◽  
Normal Faulting ◽  
Vein System ◽  
Štiavnica Stratovolcano ◽  
Dextral Strike Slip ◽  
Strike Slip Movement

The Finsterort and Anton vein system is located in the central zone of the Middle Miocene Štiavnica Stratovolcano between Vyhne and Hodruša-Hámre villages. The vein system contains several partial veins and veinlets and has generally NNE - SSW strike with moderate to steep eastward dip. Kinematics of the veins is characterised by older dextral strike-slip movement replaced by younger normal faulting. The mineralization is associated with the normal faults and the veins contain interesting paragenesis of Au-Ag bearing minerals. Minerals of precious metals are represented by argentotetrahedrite-(Zn) and rozhdestvenskayaite-(Zn), Au-Ag alloys, members of polybasite-pearceite and pyrargyrite-proustite solid solutions, acanthite and uytenbogaardtite. Au-Ag mineralization is accompanied by older paragenesis comprising mainly pyrite, galena, sphalerite and chalcopyrite. Besides quartz, carbonates (calcite, siderite and dolomite) are the main gangue minerals.

scholarly journals Dextral strike‐slip and normal faulting during middle Miocene back‐arc extension and westward Anatolia extrusion in Central Greece

Tectonics ◽  
2021 ◽  
Author(s):  
Agathe Faucher ◽  
Frédéric Gueydan ◽  
Marc Jolivet ◽  
Manar Alsaif ◽  
Bernard Célérier
Keyword(s):  
Middle Miocene ◽  
Strike Slip ◽  
Normal Faulting ◽  
Central Greece ◽  
Back Arc ◽  
Dextral Strike Slip

New Evidence of the Dextral Strike-Slip Movement in the Liaohe Basin, China: Results from Sem Experiments

2001 ◽  
Vol 44 (6) ◽  
pp. 779-784
Author(s):  
Jia-Zeng SHAN ◽  
Hong-Jun SUN ◽  
Qian-Hua XIAO ◽  
Dao-Jing WANG ◽  
Kun XU ◽  
...  
Keyword(s):  
Strike Slip ◽  
Liaohe Basin ◽  
New Evidence ◽  
Dextral Strike Slip ◽  
Strike Slip Movement

scholarly journals LATE-AND POST-ALPINE TECTONIC EVOLUTION OF THE SOUTHERN PART OF THE ATHOS PENINSULA, NORTHERN GREECE

2018 ◽  
Vol 40 (1) ◽  
pp. 309 ◽  
Author(s):  
G. Α. Georgiadis ◽  
M. D. Tranos ◽  
D. M. Mountrakis
Keyword(s):  
Late Miocene ◽  
Middle Miocene ◽  
Strike Slip ◽  
Early Pleistocene ◽  
Stress Axis ◽  
Normal Faults ◽  
Lateral Shear ◽  
Northern Greece ◽  
Lateral Strike Slip ◽  
Tectonic Features

The boundary between Internal Hellenides and the Hellenic hinterland is exposed in the southern part of the Athos peninsula as a NE-SW trending contact between the Serbomacedonian massif and the Circum-Rhodope Belt. The main tectonic features and deformation of the area during late- and post-alpine times have been investigated in order to understand better the late orogenic processes that led to the present arrangement of this boundary. The field study showed that the prevailing structures in the southern Athos peninsula are an asymmetric, SW-plunging, NWverging mega-scale antiform and a NE-SW striking left-lateral shear zone. These structures are the result of a transpressional deformation that initiated at least since the Eocene under ductile, syn-metamorphic (low-greenschist fades) conditions and progressively changed during the Oligocene-Early Miocene to brittle conditions with E-W striking reverse faults-thrusts and NNW-SSE striking right-lateral and NESW striking left-lateral strike-slip faults. This deformation waned in Middle Miocene changing to transtension with E- W striking, left-lateral strike-slip and NW-SE rightlateral oblique to normal faults. Since the Late Miocene an extensional regime dominates the area with the least principal stress axis (σ3) orientated NE-SW during Late Miocene - Pliocene andN-Sfrom Early Pleistocene -present

scholarly journals A reappraisal of active tectonics along the Fethiye-Burdur trend, southwestern Turkey

2021 ◽  
Author(s):  
Edwin Nissen ◽  
Mussaver Didem Cambaz ◽  
Élyse Gaudreau ◽  
Andrew Howell ◽  
Ezgi Karasözen ◽  
...  
Keyword(s):  
Active Tectonics ◽  
Normal Fault ◽  
Recent Change ◽  
Strike Slip ◽  
Gravitational Potential Energy ◽  
Normal Faults ◽  
Normal Faulting ◽  
Arrival Times ◽  
Anatolian Plateau ◽  
Recent Earthquakes

We investigate active tectonics in southwestern Turkey along the trend between Fethiye, near the eastern end of the Hellenic subduction zone, and Burdur, on the Anatolian plateau. Previously, regional GPS velocity data have been used to propose either (1) a NE-trending zone of strike-slip faulting coined the Fethiye-Burdur Fault Zone, or (2) a mix of uniaxial and radial extension accommodated by normal faults with diverse orientations. We test these models against the available earthquake data, updated in light of recent earthquakes at Acıpayam (20 March 2019, Mw 5.6) and Bozkurt (8 August 2019, Mw 5.8) — the largest in this region in the last two decades — and at Arıcılar (24 November 2017, Mw 5.3). Using Sentinel-1 InSAR and seismic waveforms and arrival times, we show that the Acıpayam, Bozkurt and Arıcılar earthquakes were buried ruptures on pure normal faults with subtle or indistinct topographic expressions. By exploiting ray paths shared with these well-recorded modern events, we relocate earlier instrumental seismicity throughout southwestern Turkey. We find that the 1971 Mw 6.0 Burdur earthquake likely ruptured a NW-dipping normal fault in an area of indistinct geomorphology near Salda Lake, contradicting earlier studies that place it on well-expressed faults bounding the Burdur basin. Overall, the northern Fethiye-Burdur trend is characterized by orthogonal normal faulting, consistent with radial extension and likely responsible for the distinct physiography of Turkey's 'Lake District'. The southern Fethiye-Burdur trend is dominated by ESE-WNW trending normal faulting, even though most faults evident in the topography strike NE-SW. This hints at a recent change in regional strain, perhaps related to eastward propagation of the Gökova graben into the area or to rapid subsidence of the Rhodes basin. Overall, our results support GPS-derived tectonic models that depict a mix of uniaxial and radial extension throughout southwestern Turkey, with no evidence for major, active strike-slip faults anywhere along the Fethiye-Burdur trend. Normal faulting orientations are consistent with a stress field driven primarily by contrasts in gravitational potential energy between the elevated Anatolian plateau and the low-lying Rhodes and Antalya basins.

Role of Basement Structural Inheritance and Strike-Slip Fault Dynamics in the Formation of the Pataz Gold Vein System, Eastern Andean Cordillera, Northern Peru

2021 ◽  
Author(s):  
Daniel Wiemer ◽  
Steffen G. Hagemann ◽  
Nicolas Thébaud ◽  
Carlos Villanes
Keyword(s):  
Structural Control ◽  
Structural Model ◽  
Gold Mineralization ◽  
Strike Slip ◽  
Fault System ◽  
Normal Faults ◽  
Vein System ◽  
Structural Inheritance ◽  
Andean Cordillera ◽  
Northern Peru

Abstract New regional- to vein-scale geologic mapping and structural analysis of the Carboniferous Pataz gold vein system (~10 Moz Au) reveal critical insights into the structural control on gold mineralization along the Eastern Andean Cordillera of northern Peru. The Pataz basement comprises continental volcanic arc and marginal to marine sedimentary rocks, which experienced intensive D2 deformation associated with Late Famatinian northeast to southwest compressive fold-and-thrust belt development. The D2 event produced an E-NE–dipping structural grain, including (1) tilted and F2 folded S1 foliations, (2) local F2 axial planar S2 foliations, and (3) subparallel D2 thrust faults. Intrusions, constituting the ca. 342 to 332 Ma (Mississippian) Pataz batholith, were emplaced along strike of the prominent Río Marañón fault and inherited the D2 basement structures, as evident in the orientation of suprasolidus magmatic flow zones and intrusive contacts within the batholith. Progressive horst-and-graben development affecting the volcanic carapace of the Pataz batholith records late syn- to postmagmatic uplift and transition into a NW-SE–extensional regime. We show that the E-NE–dipping, batholith-hosted gold vein system formed through synchronous activation of two geometric fault-fill vein types, following (1) the moderately E-NE–dipping D2 basement-inherited competency contrasts within the batholith and (2) shallow NE-dipping Andersonian footwall thrusts, during NE-directed shortening (D3a). Both geometric vein types display an early paragenetic stage (I) of quartz-pyrite, progressing texturally from hydraulic breccia into crack-seal laminated shear veins. A second (II), undeformed quartz-pyrite-sphalerite-galena paragenetic stage is observed to fill previously established dilational sites adjacent to newly formed D3b normal faults, which likely formed during regional NW-SE–extensional horst-graben development. Kinematics and relative timing indicate that, upon batholith solidification, D3a transpressional dextral strike-slip ruptures along the Río Marañón fault superimposed a lower-order Riedel-type fault system. Fluid-assisted fault activation preferentially impinged on the D2 basement-inherited competency contrasts within the batholith. Subsequent transition into a transtensional regime led to the D3b normal faulting, providing a feeder system for stage II fluid influx. The tectonic switch may be explained either by increasing tensile strain accommodation upon progressive strike-slip movement within a regional dilational jog or by larger-scale crustal relaxation of the late Gondwana margin upon final Pangea assembly. Our new structural model for the Pataz vein system evolution highlights the importance of basement structural inheritance in controlling the localization of gold mineralization along polycyclic supercontinent margins. We provide valuable insights for exploration targeting of complex vein arrays within rheologically heterogeneous host rocks.

A syn-collisional or post-collisional belt? In the view from the middle segment of the Central Tianshan Belt

2020 ◽  
Author(s):  
Wei Lin ◽  
Le Li
Keyword(s):  
Tectonic Evolution ◽  
Critical Role ◽  
Central Zone ◽  
Strike Slip ◽  
Orogenic Belt ◽  
Radiometric Dating ◽  
Southern Zone ◽  
Chinese Tianshan ◽  
Northern Zone ◽  
Dextral Strike Slip

<p>The Tianshan belt is one of the key regions in understanding the tectonics of the Central Asian Orogenic Belt (CAOB), as it presents a typical example of subduction, accretion and collision. Its tectonic evolution is recently in hot debate and draws more and more attention of the international geological society. As a major tectonic segment, the Middle Chinese Tianshan was considered to witness the most significant tectonic events. On the basis of structural and geochronological works, three zones have been recognized namely: 1) the northern zone, composed of weakly metamorphosed sedimentary rocks of Silurian to Carboniferous ages; 2) the central zone, comprised of well sheared amphibolite, marble, quartzo-schist, quartzite, garnet-biotite schist, and orthogneiss; and 3) the southern zone, which consists of amphibolite facies metamorphic rocks whose protolith is considered to be Silurian to Devonian. The most significant deformation was marked on the various schist or gneiss of the central zone. E-W striking, vertical or sub-vertical foliation with horizontal or sub-horizontal mineral and stretching lineations indicate conspicuous strike-slip shearing. Shear criteria indicate a dextral sense of shearand geochronological results indicates it looks like two phase deformation (~290 Ma and ~250 Ma). South-dipping foliation with northward thrusting in the northern zone and north-dipping foliation with southward thrusting in the southern zone show a large-scale flower structure related to the early stage of the dextral strike-slip tectonics of the central zone. The absolute timing of the dextral strike-slip deformation is also discussed in the light of available radiometric dating. Our structural data emphasizes that the post-collisional dextral wrenching has largely modified the architecture of the Tianshan orogenic belt and played a critical role in the tectonic evolution of Central Asia.</p>

Acadian deformation in the shallow crust: an example from the Siluro-Devonian Arisaig Group, Avalon terrane, mainland Nova Scotia

2006 ◽  
Vol 43 (1) ◽  
pp. 71-81 ◽  
Author(s):  
James A Braid ◽  
J Brendan Murphy
Keyword(s):  
Nova Scotia ◽  
Shear Zones ◽  
Thrust Fault ◽  
Structural Features ◽  
Strike Slip ◽  
Normal Faults ◽  
Progressive Deformation ◽  
Acadian Orogeny ◽  
Shallow Crust ◽  
Dextral Strike Slip

The Silurian – Early Devonian Arisaig Group of the Avalon terrane in northern mainland Nova Scotia consists mainly of thinly bedded sandstones, siltstones, and shales deposited in a near shore environment. These strata were deformed in the middle Devonian to form regional northeast- to NNE-trending folds and record deformation processes in the shallow crust during the Acadian orogeny, one of the most regionally extensive orogenic events in the Canadian Appalachians. Structural features in the Arisaig Group are consistent with fold propagation associated with thrust fault geometry and coeval local extension recorded by a set of conjugate normal faults. Many outcrop-scale folds have sheared limbs and show evidence of a complex progressive deformation. Folding was predominantly accomplished by bulk rotation and flattening above thrust fault tips. Early structures (D1–D2) produced regional cylindrical folds, whereas later (D3a, D3b, D3c) structures produced conical folds. D1–D3 fold orientations show high variability, but are consistent with progressive deformation related to reactivation and coeval dextral strike-slip movement along the Hollow Fault. The style of deformation is compatible with models in which strain is partitioned into preexisting shear zones in the basement, with folds in the overlying Arisaig Group initiated above the tips of upward-propagating thrusts as second-order structures related to movement along those shear zones. Taken together, these data indicate that fold mechanisms and geometry in the shallow crust during the Acadian orogeny in mainland Nova Scotia may be related to dextral strike-slip along major faults in the basement and co-genetic upward-propagating thrusts that rotated and flattened overlying strata.

scholarly journals The Germania Land deformation zone and related structures, North-East Greenland

1994 ◽  
Vol 162 ◽  
pp. 113-127
Author(s):  
J.M Hull ◽  
J.A Gilotti
Keyword(s):  
Deformation Zone ◽  
Strike Slip ◽  
Low Grade ◽  
High Grade ◽  
Normal Faulting ◽  
East Greenland ◽  
North East ◽  
Parallel Movement ◽  
Land Deformation ◽  
Dextral Strike Slip

The Germania Land deformation zone in North-East Greenland consists of two subparallel, NW-striking strands of mylonites and cataclasites. The quasiplastic mylonites formed under low grade (biotite zone) conditions following high grade Caledonian metamorphism. Displacements on the Germania Land deformation zone and parallel zones at Danmarkshavn were predominantly dextral strike slip. Along with the similar, but sinistral, Storstrømmen shear zone, these zones record a late Caledonian phase of orogen-parallel movement. The Germania Land deformation zone is also the locus of Carboniferous normal faulting and basin development.

Role of dextral strike slip faulting in the distribution of Aegean extension since Miocene times inferred from receiver function analysis

2020 ◽  
Author(s):  
Agathe Faucher ◽  
Christel Tiberi ◽  
Frédéric Gueydan ◽  
Alexandrine Gesret
Keyword(s):  
Receiver Function ◽  
Function Analysis ◽  
Receiver Functions ◽  
Strike Slip ◽  
Point Of View ◽  
Normal Faults ◽  
The South ◽  
Crustal Thinning ◽  
Dextral Strike Slip

<p>Aegean plate is marked since Eocene by widespread NE-SW extension induced by the African slab roll-back. In Miocene times, E-W shortening created by the westward Anatolian extrusion overlays the extension, with the formation of Miocene dextral strike slip faults in addition to normal faults. We propose to quantify the role of large dextral strike slip faults in accommodating Aegean extension, using receiver functions to image Moho geometry.</p><p>Aegean extension is particularly evidenced by a topographic difference between the emerged continental Greece and the submerged Cyclades. In this study we characterize the associated Moho geometry with a particular focus on the transition between these two domains. From a geological point of view, the transition between continental Greece and the Cyclades is marked by two dextral strike slip faults: the Pelagonian fault (onshore) and the South Evvia fault (offshore). Our objective is also to show a potential Moho signature of these strike slip faults.  We processed receiver functions (RF) from the MEDUSA stations located in Attic and Evvia.</p><p>Our results show that the Moho is deeper beneath continental Greece (~27km) than beneath the Cyclades (~25km). A detailed azimuthal study of RF distribution shows a flat Moho underneath Continental Greece. The crustal thickness is also almost constant inside the Cyclades, as already suggested by previous studies. However, the transition between the Cyclades and Continental Greece is not continuous. These two crustal blocks are separated by the Pelagonian and the South Evvia strike slip faults in a narrow transition zone (~75km). In this zone (South Evvia/Attica), dip and strike of the Moho vary and suggest a crustal signature of the strike slip structures observed at the surface. These strike slip faults therefore accommodate in a narrow zone the inferred variations in crustal thicknesses between the Cyclades and Continental Greece.</p><p>Our data show that differences in topography between Continental Greece and the Cyclades are isostatically compensated, reflecting various amount of crustal thinning larger in the Cyclades than in Continental Greece. Inside these two crustal blocks, we imaged a flat Moho, suggesting a wide rift extension process associated with the formation of numerous Miocene and Plio-Quaternary basins.  The dextral strike slip faults at the edges of the continental blocks (Continental Greece and Cyclades) accommodated the inferred variations in the amount of crustal thinning, suggesting that they act as continental transfer zones at crustal-scale during Miocene Aegean Extension.</p>

Structural evolution of basement gneisses and Hadrynian cover, Bulldog Creek area, Rocky Mountains, British Columbia

1988 ◽  
Vol 25 (10) ◽  
pp. 1687-1702 ◽  
Author(s):  
Michael R. McDonough ◽  
Philip S. Simony
Keyword(s):  
British Columbia ◽  
Structural Evolution ◽  
Rocky Mountain ◽  
Strike Slip ◽  
Normal Faulting ◽  
The West ◽  
Kinematic Indicators ◽  
Thrust Sheets ◽  
Dextral Strike Slip ◽  
Southern Rocky Mountain

Two gneiss bodies are contained in thrust sheets on the west edge of the Rocky Mountain Main Ranges near Valemount, British Columbia. The Bulldog Gneiss comprises Aphebian or older paragneiss and amphibolitic gneiss intruded by Aphebian orthogneiss sheets. The Yellowjacket Gneiss is granodioritic orthogneiss of unknown age. Both gneiss bodies are basement highs with thin Hadrynian metasediment cover sequences. The cover sequences are assigned to the lower Miette Group and are correlated with Horsethief Creek Group.Internal shortening of gneiss thrust sheets is expressed by recumbent folding and stacking of thin thrust sheets of gneiss and cover. The Bulldog Gneiss and its cover were carried on the postmetamorphic Purcell Thrust. The Yellowjacket Gneiss and its cover were carried on the pre- to synmetamorphic Bear Foot Thrust. Northeast and northwest displacement is documented on the moderately southwest-dipping Bear Foot Thrust, and a dextral oblique-slip – thrust model is proposed to explain the duality of thrust and dextral strike-slip kinematic indicators in mylonite from the fault. An estimate of shortening in the fore-land suggests that basement thrust sheets were translated more than 200 km to the northeast.Correlation of gneisses and cover with the westerly adjacent Malton Gneiss and its cover precludes major dextral strike-slip motion on the Southern Rocky Mountain Trench (SRMT) during and after thrusting. The SRMT was the locus of post-thrusting and postmetamorphic, Eocene(?), brittle, west-side-down, normal faulting.

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