Relative tectonic activity assessment of the Tuz Gölü Fault Zone; Central Anatolia, Turkey

2014 ◽  
Vol 630 ◽  
pp. 183-192 ◽  
Author(s):  
Cengiz Yıldırım
2016 ◽  
Vol 0 (152) ◽  
Author(s):  
Korhan ESAT ◽  
Bülent KAYPAK ◽  
Veysel IŞIK ◽  
Berkan ECEVİTOĞLU ◽  
Gürol SEYİTOĞLU

2019 ◽  
Vol 10 (2) ◽  
pp. 561-567
Author(s):  
N. F. Vasilenko ◽  
A. S. Prytkov

In the northern Sakhalin Island, the tectonic activity of the fault zones is a potential threat to the industrial infrastructure of the petroleum fields. Recently, the background seismicity has increased at the Hokkaido‐Sakhalin fault that consists of several segments, including the Garomai active fault. In the studies of the regional deformation processes, it is important not only to analyze the seismic activity, but also to quantitatively assess the dynamics of deformation accumulation in the fault zones. In order to study the contemporary geodynamics of the Garomai fault, a local GPS/GLONASS network has been established in the area wherein trunk oil and gas pipelines are installed across the fault zone. Based on the annual periodic measurements taken in 2006–2016, we study the features of surface deformation and calculate the rates of displacements caused by the tectonic activity in the fault zone. During the survey period, no significant displacement of the fault wings was revealed. In the immediate vicinity of the fault zone, multidirectional horizontal displacements occur at a rate up to 1.6 mm/yr, and uplifting of the ground surface takes place at a rate of 3.4 mm/yr. This pattern of displacements is a reflection of local deformation processes in the fault zone. At the western wing of the fault, a maximum deformation rate amounts to 1110–6 per year. The fault is a boundary mark of a transition from lower deformation rates at the eastern wing to higher ones at the west wing. In contrast to the general regional compression setting that is typical of the northern Sakhalin Island, extension is currently dominant in the Garomai fault zone. The estimated rates of relative deformation in the vicinity of the Garomai fault give grounds to classify it as ‘hazardous’.


1966 ◽  
Vol 3 (5) ◽  
pp. 639-658 ◽  
Author(s):  
P. S. Kumarapeli ◽  
V. A. Saull

The St. Lawrence valley system (including the St. Lawrence, Ottawa, and Champlain valleys, and the St. Lawrence or Cabot trough) is coextensive with a well-defined pattern of seismic activity. The valley system is in a region of general updoming, normal faulting, and alkaline igneous activity of a distinctive type. The main phase of tectonic activity probably dates back to Mesozoic time. The above and other evidence presented in this paper indicate the existence of a major rift valley system that may be called the St. Lawrence rift system.The Rough Creek – Kentucky River fault zone, and the normal fault zones in Texas and Oklahoma, and the Lake Superior fault zone probably represent extensions of the St. Lawrence rift system. However, current seismicity indicates that the present tectonic activity is along a straight zone running through lakes Ontario and Erie into the Mississippi embayment. The St. Lawrence rift system may also be connected with the mid-Atlantic rift, in the region of the Azores plateau.The rift hypothesis presented may be useful as a regional guide in the search for niobium-bearing alkaline complexes and diamond-bearing kimberlites.Crustal tension in the St. Lawrence region may be genetically related to the opening of the Atlantic basin as postulated in the hypothesis of continental drift.


1978 ◽  
Vol 88 (4) ◽  
pp. 769-792 ◽  
Author(s):  
D. R. Kassoy ◽  
A. Zebib

Faulted regions associated with geothermal areas are assumed to be composed of rock which has been heavily fractured within the fault zone by continuous tectonic activity. The fractured zone is modelled as a vertical, slender, two-dimensional channel of saturated porous material with impermeable walls on which the temperature increases linearly with depth. The development of an isothermal slug flow entering the fault at a large depth is examined. An entry solution and the subsequent approach to the fully developed configuration are obtained for large Rayleigh number flow. The former is characterized by growing thermal boundary layers adjacent to the walls and a slightly accelerated isothermal core flow. Further downstream the development is described by a parabolic system. It is shown that a class of fully developed solutions is not spatially stable.


Geosciences ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 264
Author(s):  
Kanella Valkanou ◽  
Efthimios Karymbalis ◽  
Dimitris Papanastassiou ◽  
Mauro Soldati ◽  
Christos Chalkias ◽  
...  

The aim of this study is to evaluate the relative tectonic activity in the north part of the Evia Island, located in Central Greece, and to investigate the contribution of neotectonic processes in the development of the fluvial landscape. Five morphometric parameters, including Drainage Basin Slope (Sb), Hypsometric Integral (Hi), Asymmetry Factor (Af), Relief Ratio (Rh), and Melton’s Ruggedness Number (M), were estimated for a total of 189 drainage basins. The catchments were classified into two groups, according to the estimated values of each morphometric parameter, and maps showing their spatial distribution were produced. The combination of the calculated morphometric parameters led to a new single integrated Index of relative tectonic activity (named Irta). Following this indexing, the basins were characterized as of low, moderate, or high relative tectonic activity. The quantitative analysis showed that the development of the present drainage systems and the geometry of the basins of the study area have been influenced by the tectonic uplift caused by the activity of two NW-SE trending offshore active normal fault systems: the north Gulf of Evia fault zone (Kandili-Telethrion) and the Aegean Sea fault zone (Dirfis), respectively. The spatial distribution of the values of the new integrated index Irta showed significant differences among the drainage basins that reflect differences in relative tectonic activity related to their location with regard to the normal fault systems of the study area.


2020 ◽  
Vol 178 (1) ◽  
pp. jgs2020-101
Author(s):  
L.R. Campbell ◽  
G.E. Lloyd ◽  
R.J. Phillips ◽  
R.C. Walcott ◽  
R.E. Holdsworth

Heterogeneous sequences of exhumed fault rocks preserve a record of the long-term evolution of fault strength and deformation behaviour during prolonged tectonic activity. Along the Outer Hebrides Fault Zone (OHFZ) in NW Scotland, numerous pseudotachylytes record palaeoseismic slip events within sequences of mylonites, cataclasites and phyllonites. To date, the kinematics and controls on seismicity within the long active history of the OHFZ have been poorly constrained. Additional uncertainties over the relative location of a meteorite impact and possible pre-OHFZ brittle faulting also complicate interpretation of the diffuse seismic record. We present kinematic analyses of seismicity in the OHFZ, combining observations of offset markers, en echelon injection veins and injection vein geometry to reconstruct slip directions and stress fields. This new dataset indicates that a range of fault orientations, slip directions and slip senses hosted seismicity in the OHFZ. Such complexity requires several stress field orientations, in contrast with the NW–SE Caledonian compression traditionally attributed to frictional melting along the OHFZ, indicating that seismicity had a long-term presence across the fault zone. Persistence of strong frictional failure alongside the simultaneous development of weak fault rocks and phyllonitic shear zones in parts of the OHFZ has significant implications for understanding seismic hazard along mature continental faults.Supplementary material: Tables listing analysed orientation measurements plus further information and sensitivity testing of palaeostress analysis parameters are available at https://doi.org/10.6084/m9.figshare.c.5134797


1981 ◽  
Vol 18 (9) ◽  
pp. 1431-1442 ◽  
Author(s):  
R. D. Dallmeyer ◽  
R. F. Blackwood ◽  
L. Odom

The Dover Fault forms a tectonic boundary between northern portions of the Gander and Avalon Zones of the Newfoundland Appalachians. A systematic geochronological investigation across the mylonitic fault zone has been carried out to clarify the origin and history of tectonic activity along this important Appalachian structure.Zircon fractions from the mylonitic Lockers Bay Granite (Gander Zone) record individually discordant U–Pb dates, but yield a well-defined upper concordia intercept age of 460 ± 20 Ma. Hornblende (1 sample) and biotite (11 samples) from variably mylonitic Gander Zone lithologies (plutonic and metamorphic) adjacent to the fault zone record undisturbed 40Ar/39Ar age spectra with plateau ages of 395 and 365–383 Ma, respectively. Together with field and petrographic characteristics, the new geochronologic data suggest that the Lockers Bay Granite originated as an anatectic melt during high-grade regional metamorphism of the country rock terrane at approximately 460 Ma. The crystal-rich magma was subsequently emplaced into its present position thereby producing local discordance with small-scale structures in host gneisses.Following its emplacement, the Lockers Bay Granite and country rock terrane were maintained at elevated postmetamorphic temperatures for a prolonged interval until they underwent rapid strain during Acadian (Devonian) juxtaposing of the northern Gander and Avalon Zones along the Dover Fault. Sudden Acadian uplift along the fault is suggested because of the rapid cooling of the northern Gander Zone through temperatures required for argon retention in hornblende and biotite. Post-mylonite brecciation may have locally affected argon isotopic systems of phyllitic lithologies adjacent to the fault zone in the study area.


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