Tectonics
Mohamad Reza Sajadian; Manouchehr Ghorashi; Elahe Javadi Mosavi; Mohsen Pourkermani; Mehran Arian
Volume 28, Issue 110 , December 2018, , Pages 299-306
Abstract
Geomorphic indices of active tectonics are useful tools to analyze the influence of active tectonics. These indices have the advantage of being calculate from ArcGIS and remote sensing packages over large area as a reconnaissance tool to identify geomorphic anomalies possibly related to active tectonics. ...
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Geomorphic indices of active tectonics are useful tools to analyze the influence of active tectonics. These indices have the advantage of being calculate from ArcGIS and remote sensing packages over large area as a reconnaissance tool to identify geomorphic anomalies possibly related to active tectonics. This is particularly valuable in west-central Alborz where relatively little work on active tectonics based on this method was done, so this method is new and useful. Based upon values of the stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), index of drainage basin shape (Bs), index of mountain front sinuosity (Smf) and transverse topographic symmetry factor (T), we used an overall index (Iat) that is a combination of the other indices. The low class of Iat are mainly in the sub-basins no; 6, 10,13,14,21,22,23,24,28 and the rest of the study area has moderate tectonic activities in the other sub-basins. Our results show that he moderate value has located along faulted area, which shows 2 class of relative tectonic activity.
R. Gholipour; A. Solgi; Y. Sattarzadeh-Ghadim; A. Sorbi
Abstract
Geomorphic indices of active tectonics are useful tools to analyze of the active tectonics in a large area. These indices have the advantage of being calculate from the software and remote sensing packages over large area as a reconnaissance tool to identify geomorphic anomalies possibly related to active ...
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Geomorphic indices of active tectonics are useful tools to analyze of the active tectonics in a large area. These indices have the advantage of being calculate from the software and remote sensing packages over large area as a reconnaissance tool to identify geomorphic anomalies possibly related to active tectonics. This is particulary valuable in Ajichai basins where relatively little work on active tectonics based on this method was done, so this method is new and useful. Based upon valuable of the stream length-gradient index(SL), drainage basins asymmetry(Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), drainage basins index shape (Bs), and index of mauntain front sinuosity (Smf), we used an overall index (Iat), that is a combination of the other indices that divides the landscape into four classes of relative tectonic activity. The moderate class of Iat is mainly in the class 2 (high), with 1045.46 Km2 ,11.26 percent, class 3 (moderate), with 2940.67 Km2 ,31.67 percent and with 5297.30 Km2 ,57.06 percent occupying of all zone. The stream network asymmetry (T) was also studied using morphometric measures of Transverse Topographic Symmetry. Analysis of the drainage basins and sub-basins in the study area results in a field of T-vectors that defines anomalous zone of the basins asymmetry. A comparison of T index clearly consist with the values and classes of active tectonics indices and the overall Iat index.
A Khodabakhshnezhad; M Pourkermani; M Arian; A.A Matkan; A Charchi
Abstract
Geomorphic indices of active tectonics are useful tools to analyze the influence of active tectonics in an area. These indices have the advantage of being calculated using ArcGIS and RS (Remote Sensing) packages over large areas as a reconnaissance tool to identify geomorphic anomalies possibly related ...
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Geomorphic indices of active tectonics are useful tools to analyze the influence of active tectonics in an area. These indices have the advantage of being calculated using ArcGIS and RS (Remote Sensing) packages over large areas as a reconnaissance tool to identify geomorphic anomalies possibly related to active tectonics. This is particularly valuable in Great Karoun River Basin of Zagros, where relatively little work on active tectonics based on this method was done. The study area in central Zagros fold- thrust-belt of the southwestern Iran is an area with NW–SE oriented structures provides an ideal location for testing the concept of an index to predict relative tectonic activity on a basis of river system or mountain front. Based upon values of the stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), index of drainage basin shape (Bs), and index of mountain front sinuosity (Smf), overall index as index of relative active tectonic (Iat) was resulted that is a combination of the other indices. This indices are used to divide the landscape into four classes of relative tectonic activity. After measuring indices it is concluded that this part of the Zagros zone has variable rates of active tectonics. Based on corrected Iat values, the study area was divided into three parts: class 1 (very high relative tectonic activity, %24 in area; such as some parts of the east and central zone where Main Zagros Reverse Fault and Dezful embayment fault have the most influence); class 2 (high relative tectonic activity, 63% in area; such as most parts of the area in east, west, north and center where action of faults are lower than the previous class); class 3(moderate, 10% in area; such as most parts of the area in north and south where action of faults are the lowest). Therefore, we don't have class 4 in this area, and 1% of basin is not measured for the indices because it is located in coastal plain of Khuzestan.
J Ehsani; M Arian; M Ghorashi
Abstract
This paper aims at evaluating relative active tectonics in the Jarahi-Hendijan drainage basin based on geomorphic indices. Indices used include: stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), index of drainage ...
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This paper aims at evaluating relative active tectonics in the Jarahi-Hendijan drainage basin based on geomorphic indices. Indices used include: stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), index of drainage basin shape (Bs), and index of mountain front sinuosity (Smf). Results from the analyses were combined to achieve an index of relative active tectonics (Iat), which is divided into four classes implying relatively low to very high tectonic activity. The study area is located across the Zagros Mountains belt (high Zagros, folded belt, and frontal lowlands) in southwest Iran, and comprises an ideal location to test the concept of an index to predict relative tectonic activity on a basis of area rather than a single valley or mountain front. Recent investigations show that neotectonism has played a key role in the geomorphic evolution of this part of the Zagros ranges. Geomorphic indices indicate the presence of differential uplifting in the geological past. Higher values of Iat (low tectonic activity) mainly occur in the southwest of the Jarahi- Hendijan drainage basin, while the rest of the study area falls into classes of Iat that indicate moderate to high tectonic activity. Baghmalek and Takhtderaz sub-basins show the highest values of relative tectonic activity. The distribution of this index defines areas associated with different faults and relative rates of tectonic activity. Nearly 40% of the study area is classified into Classes 1 and 2 implying very high to high tectonic activity, and 37% is grouped as Class 4, which is taken to indicate low tectonic activity. Areas of higher relative tectonic activity represent lower Iat values.
M Haj Manuchehri; M Arian; M Ghorashi; A Solgi; A Sorbi
Abstract
Geomorphic indices of active tectonics are useful tools to analyze the influence of active tectonics. These indices have the advantage of being calculated from ArcGIS and Remote Sensing software packages over large areas as a reconnaissance tool to identify possible geomorphic anomalies related to active ...
Read More
Geomorphic indices of active tectonics are useful tools to analyze the influence of active tectonics. These indices have the advantage of being calculated from ArcGIS and Remote Sensing software packages over large areas as a reconnaissance tool to identify possible geomorphic anomalies related to active tectonics. This method is particularly new and useful in areas where relatively little work has been carried out on active tectonics based on this method. Based upon the values of stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), index of drainage basin shape (Bs), and index of mountain front sinuosity (Smf), we used an integrated index (Iat) that is a combination of the other indices. This index divides the landscape into four classes of relative tectonic activity. According to the Iat results, sub-basins 4 and 6 show zones of low tectonics activity (Class 4), sub-basins 1, 2, 7, 9, 10, 11, 12, 14, 15 and 19 fit to areas of moderate tectonic activity (Class 3), and high tectonic activity is represented by sub-basins 3, 5, 8, 13, 16, 17 and 18 (Class 2). The Tranverse Topographic Symmetry (T) was also studied using morphometric measurements, which finally gave a plot of T-vectors defining anomalous zones of basin asymmetry. A comparison between T index and map of relative tectonic activity showed a consistent coincidence between areas of higher Iat classes with zones of greater asymmetry.
N Bagha; M Ghorashi; M Arian; M Pourkermani; A Solgi
Abstract
Structural development, caused by active tectonics leads to deformation of morphology features. The Mosha-North Tehran fault zone, located in south edge of the Central Alborz consists of significant tectonic structures. Hence, study on morphotectonic signs is a proper method for evaluation of relative ...
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Structural development, caused by active tectonics leads to deformation of morphology features. The Mosha-North Tehran fault zone, located in south edge of the Central Alborz consists of significant tectonic structures. Hence, study on morphotectonic signs is a proper method for evaluation of relative tectonic activities in the area. In this research, six main morphometric indices such as stream length-gradient (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height(Vf), drainage basin shape (Bs), and mountain front sinuosity(Smf)were considered. The computations and probes of these indices indicate three classes of relative tectonic activity in the study area from low to high level. Consequently, the drainage basins with high class of tectonic activity mostly coincide with the main faults in south edge of the Central Alborz.
B Azadbakht; M Zareinejad
Abstract
Water causes erosion of different forms in nature and creates diverse landforms on the earth’s surface depending on the manner it appears in nature. Although water is itself a former factor, it flows under the morphological effect of earth’s surface (Ramasht, 2005). The difference of earth’s ...
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Water causes erosion of different forms in nature and creates diverse landforms on the earth’s surface depending on the manner it appears in nature. Although water is itself a former factor, it flows under the morphological effect of earth’s surface (Ramasht, 2005). The difference of earth’s surface topography and its consequent of water movement on it, cause the formation of sub-basins. In order to recognition of morphology and morphometry of Damavand cone, the region drainage basins must be distinguished. Therefore, in this study 5 drainage basins were identified based on the main criteria including topographic contours with 10 m intervals, drainage system (main and subsidiary rivers, main and subsidiary streams), DEM map of the region, slope map, aspect map and satellite images. Area, perimeter, height classification for classifying the morphological landforms in different levels, hypsometric, drainage density, etc. were then calculated by using the ArcGIS software. The Damavand cone, with a height more than 5,000 m above the sea level, has a very hard-pass slopes. Our purpose in this paper is to identify the effect of drainage basins conditions on the erosion and formation of geomorphological landforms by using of SPOT and ASTER satellite images as well as data analysis o in GIS environment.
Z. Mardani; M. Ghorashi; M. Arian; Kh. Khosrotehrani
Abstract
Geomorphic indices of active tectonics are useful tools to analyze the influence of active tectonics.These indices have the advantage of being calculate from ArcGIS and remote sensing packages over large area as a reconnaissance tool to identify geomorphic anomalies possibly related to active tectonics.This ...
Read More
Geomorphic indices of active tectonics are useful tools to analyze the influence of active tectonics.These indices have the advantage of being calculate from ArcGIS and remote sensing packages over large area as a reconnaissance tool to identify geomorphic anomalies possibly related to active tectonics.This is particulary valuable in west-central Alborz where relatively little work on active tectonics based on this method was done,so this method is new and useful. Based upon values of the stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), index of drainage basin shape (Bs), and index of mountain front sinuosity (Smf),we used an overall index(Iat) that is a combination of the other indices that divides the landscape into four classes of relative tectonic activity. The moderat class of Iat is mainly in the south of Manjel dam,while the rest of the study area has high active tectonics (shahrud drainage basin and sefidrud drainage basin),and high to very high(Taleghan and Alamut drainage basin). The stream network asymmetry (T)was also studied using morphometric measures of Tranverse Topographic Symmetry.Analysis of the drainage basins and subbasins in the study area results in a field of T-vectors that defines anomalous zone of the basin asymmetry.Acomparsion of T index clearly coincide with the values and classes of active tectonics indices and the overall Iat index.
R. Khavari; M. Ghorashi; M. Arian; Kh. Khosrotehrani
Abstract
The paper presents a method for evaluating relative active tectonics based on geomorphic indices useful in evaluating morphology and topography. Indices used include: stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height ...
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The paper presents a method for evaluating relative active tectonics based on geomorphic indices useful in evaluating morphology and topography. Indices used include: stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), index of drainage basin shape (Bs), and index of mountain front sinuosity (Smf). Results from the analysis are accumulated and expressed as an index of relative active tectonics (Iat), which divided into four classes from relatively low to highest tectonic activity. The study area along the south flank of the central Alborz mountain range in north Iran is an ideal location to test the concept of an index to predict relative tectonic activity on a basis of area rather than a single valley or mountain front. The recent investigations show that neotectonism has played a key role in the geomorphic evolution of this part of the Alborz mountain range. Geomorphic indices indicate the presence of differential uplifting in the geological past. The high class values (low tectonic activity) for Iat mainly occur in the south and southeast of the Karaj drainage basin, while the rest of the study area has classes of Iat suggesting moderate to high tectonic activity. Around the Amirkabir Lake, Iat has the highest value. The distribution of the indices defines areas associated with different mountain fronts and estimates of relative rates of tectonic activity. More than half of the study area is classified into classes 2 or 1 of high to very high tectonic activity in terms of the apparent geomorphic response. In different tectonic environments with greater rates of active tectonics, the values of indices would differ as well as their range in value. The stream network asymmetry (T) was also studied using morphometric measures of Transverse Topographic Symmetry. Analysis of the drainage basin and a number of sub-basins in the study area results in a field of T-vectors that defines anomalous zones of the basin asymmetry. We test the hypothesis that areas with great stream migration are associated with indicatives values of Iat.
N. Haghipour
Abstract
Folded and faulted Kopeh Dagh-Binalud belt in the northeast of Iran is a part of Eurasia and southern margin of Touran plate. What is now observed is the result of the latest Phase of Alpine folding. The morphology of the area is in early stage and its young ...
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Folded and faulted Kopeh Dagh-Binalud belt in the northeast of Iran is a part of Eurasia and southern margin of Touran plate. What is now observed is the result of the latest Phase of Alpine folding. The morphology of the area is in early stage and its young folds express direct relevance between topography and geological structures. In order to evaluate uplift and distribution of compressional forces, stream- gradient (SL) and hypsometric (HI) analyses were carried out for 85 subbasins and 98 rivers of the major basins of the area (Atrakrud, Kashafrud, Jajarm, Gorganrud and Tourkamanestan plain rivers). Integration of the morphometric maps of SL and HI illustrates clearly the tectonic anomalies. Five highly uplifted morphotectonic zones were identified based on the morphotectonic indices as follows:
1) The middle part of Ashkabad Fault between geographical coordinates of: 56 47 E, 38 35 N to 57 34 E, 37 56N.
2) Gorganrud's sub-basins particularly located between Shavard fault (in the south) and eastern part of the Khazar fault (in the north).
3) Basins associated with Nokhandan, Qareh –Dagh, Sorkhdeh and Amrudak Faults.
4) Basins associated with Shogan and Gelli Faults are the Jajarm subbasins.
5) The northern foothill basins of BinaludMountain, compared with the southern foothill basins, show remarkable higher uplifting and shortening which seem to be related to the Binaloud and North Neyshabur fault.
In addition to high uplifted zones, some intermediate – low uplifted zones such as west - southwest part of Sarakhs, southern foothill subbasins of Atrakrud (associated with Takalkuh Fault and Ashkhaneh fault zone), Jajarm's subbasin in the eastern part of AladaghMountain were recognized.
