Geogr. Fis. Dinam. Quat. 35 (2012), 61-68, 8 figg., 3 tabb. DOI 10.4461/GFDQ.2012.35.6 MEHDI MUMIPOUR (*), MOHAMMAD H. REZAEI-MOGHADDAM (**) & ALI M. KHORSHIDDOUST (**) ACTIVE TECTONICS INFLUENCE ON DRAINAGE NETWORKS IN DINARKOOH REGION, ZAGROS MOUNTAIN RANGE, IRAN ABSTRACT: MUMIPOUR M., REZAEI-MOGHADDAM M.H. & KHORSHIDDOUST A.M., Active Tectonics Influence on Drainage Networks in Dinarkooh Region, Zagros Mountain Range, Iran. (IT ISSN 0391-9838, 2012). Drainage networks are usually influenced by the type, orientation and recent activity of regional and local faults and folds in tectonically active regions. In the Zagros Mountain Range, Western Iran, most drainage systems are controlled by neotectonics processes. The development of the drainage system of Dinarkooh region in the late Quaternary depends mostly on the activity of Main Zagros Thrust Fault (MZTF) and similar NW-SE oriented faults in Zagros fault system. We have done a geomorphometric study by observing river profile and characteristics of mountain fronts in order to find spatial variations and style of rock uplift. Mountain front sinuosity (Smf), area- altitude relations (Hypsometric curves), Vf and AF indices differ significantly between different parts of the study area. River profiles indicate maximal river entrenchment in the southern part of Dinarkooh Region, probably related to the uplift of footwall of MZTF fault system. Therefore our geomorphic analysis suggests that Southern and Western parts of Dinarkooh are tectonically more active and also Samand active fold plays a significant role in this activity because of an active blind thrust fault beneath it. KEY WORDS: Active Tectonics, Drainage Network, Geomorphometry, Digital Elevation Model, Dinarkooh Region, Zagros Mountain Range. (IT ISSN 0391-9838, (2012). (*) Physical Geography Department, University of Tabriz, Tabriz 51666-16471, Iran. Corresponding author, e-mail: mumipur@tabrizu.ac.ir (**) Physical Geography Department, Faculty of Humanities and Social Sciences, University of Tabriz, Tabriz - 51666-16471, Iran. Authors like to thank Dr. Faisal Shahzad for his valuable guides to use MATLAB scripts. Support from Research Council of University of Tabriz is gratefully acknowledged. We would thank anonymous reviewers for their comments that improve this manuscript. INTRODUCTION One of the fastest growing disciplines in earth sciences is active tectonics because of its developments in techniques and forwarding to more accurate analysis (Keller & Pinter, 2002; Bull, 2007, 2009a, b; Pérez-Peña & alii, 2010). Another reason is importance of its results for regional studies on active tectonics and evaluates hazards of natural disasters such as earthquakes (e.g., Cloetingh & Cornu, 2005; Pérez-Peña & alii, 2010). In Dinarkooh region, the study of active tectonics of Zagros on drainage network is important for landuse planning programs. Recent and active tectonics is considered as the main factor affecting rock uplift on mountains ranges and their present-day topography is the result of the competition between tectonics and erosion processes. So drainage pattern analysis and geomorphic features can be used for evaluating active tectonics (e.g., Keller & alii, 2000; Beneduce & alii, 2004; Capolongo & alii, 2005; Bull, 2007; Bishop, 2007; Ribolini & Spagnolo, 2008; Pérez-Peña & alii, 2010; Mumipour & Nejad, 2011). This paper aims to evaluate the active tectonics control and influence on drainage network evolution in Dinarkooh region located in the Zagros mountain range (Western Iran) by using geomorphic indices and stream profile analysis. Dinarkooh Region is a part of Western Zagros Fold 61 and thrust belt, and it posed on the Northern flank of Iranian-Arabian collision zone. For examining the influence of tectonics activity on drainage networks and get conclusions about the evolution of the area detailed geomorphometric analysis was done focusing on knickpoints and slope changes. For extracting geomorphological characteristics with quantitative measurements, the longitudinal profiles of main streams and hypsometric curves of the basins were analysed (Maroukian & alii, 2008). The tectonic setting of the Dinarkooh Region is influenced by the NW-SE trend of subduction of the Arabian plate beneath Iranian plate as shown in fig. 1. The drainage networks in active regions are strongly and rapidly influenced by tectonics and erosion changes, and hence they are potential instruments for tectonic geomorphology analysis. The drainage network of Dinarkooh has showed good geological record of the movement, displacement, regional uplifts and erosion of tectonic units. The Meymeh River crosses Dinarkooh. It divides the Dinarkooh into Western, Central and Eastern parts (fig. 2). We prepared the Digital Elevation Model (DEM) of study area from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite stereo images. MATLAB script files (Shahzad & alii, 2009; Shahzad & Gloaguen, 2011) were used to extract drainage network and lineaments from DEM. By the stream profile analysis, uplift rates of each stream were calculated under certain assumptions. The streams in central and southern Dinarkooh showed high steepness and concavity indices as compared to the streams in northern and western Dinarkooh. Spatial distribution of geomorphic indices and uplift rates differentiated among eastern, central and western parts. The central and southern parts showed more deformation and high uplift rates. FIG. 2 - Hillshade of study area showing 4 main basin and 4 main streams. Inner numbered points show the location of Valley cross sections that used to calculate Vf. Outer numbers are Basin number. STUDY AREA The study area is located between 32° 52´ N and 33° 08´ N latitudes, and 46° 54´ E and 47° 17´ E longitudes, in the western Zagros Fold and Thrust Belt (ZFTB) in southwestern Iran (figs. 1 and 2). The Zagros Mountain range hosts more than half of the world’s known hydrocarbon reserves (Sepehr & Cosgrove, 2005). Compressional tectonics led to folding, thrusting, and large-scale strike-slip faulting and significant crustal shortening in the Zagros Mountains. The basement has gone through an extensional tectonic event during the Precambrian before the deposition of the Cambrian sediments (e.g., Stocklin 1968; Berberian & King, 1981; Berberian, 1995; Mobasher, 2007). The compressional Zagros orogeny formed a variety of asymmetric, NW-SE trending, en-echelon folds, and NEdipping thrusts on the southwestern limbs of the folds. Fold axial planes generally dip to N-NE, so that the southern limbs of the folds are steeper, and in some cases they are overturned or vertical (Mobasher, 2007). Our study area is located in Zagros folded belt, northern Balaroud Fault. Samand anticline, located in this region, is one of the major gas reservoirs in Iran. METHODOLOGY FIG. 1 - Generalized tectonic map of Iranian-Arabian collision zone (modified form Homke & alii, 2004). The study area is represented by white rectangle and shown in detail in figure 2. MZT: Main Zagros Thrust; HZF: High Zagros Fault; MMF: Mountain Front Flexure. 62 Satellite images are available in variety of resolutions, so this can affects the quality of analysis. We used the ASTER DEM of 15 m spatial resolution to extract drainage network and lineaments. The drainage network is extracted from digital elevation model (DEM) of the area by calculating flow directions at all points using D8 algorithm (O’Callaghan & Mark 1984). Flow direction is related to specific basin area and upslope area, that both of them can be calculated using DEM and capabilities of GIS. Choosing stream delineation algorithms may affect the results, for example slope, area and stream strahler order may vary in different algorithms. Stream longitudinal profiles are identified and selected based on least cost path analysis that computes the paths of least resistance down slope (i.e. the downstream flow path). This algorithm was implemented in MATLAB (Shahzad & Gloaguen, 2011) and all of the required parameters were calculated. Applying stream profile analysis on each stream, valuable information was obtained. GEOMORPHIC INDICES STREAM POWER LAW Mountain front sinuosity (Smf) The lithological or structural contrasts force the streams to reach a new equilibrium condition. Mathematically, this is written in the following equation: Mountain front sinuosity (Smf ) was defined by Bull (1977) as: dz — = U – E = U – KAmSn dt 1 – () (2) Where m/n is the concavity of the profile and coefficient is steepness of the profile. So, it can be written as: –q S = Ks A (3) that q and ks are concavity and steepness indices, respectively. They can be calculated directly using regression analysis of data as shown in equation 3, i.e., area and slope (Howard, 1994; Montgomery & alii, 1996; Snyder & alii, 2000; Whipple, 2004; Wobus & alii, 2006; Shahzad & alii, 2009). By combining equations 2 and 3, a useful relationship for calculating uplift rates is presented below: U = knsn K Lmf Smf = —– Ls (1) that U and E are uplift and erosion rates, respectively. K is erosion efficiency factor which is related to sediments and rock strength directly, A is upstream drainage area and S is channel slope. The constants m and n are dependent on basin hydrology, hydraulic geometry and erosion process. dz/dt is the rate of changing elevation within specific time. So, if landscape is in steady-state condition, then it is equal to 0. Thus for a steady state equilibrium, equation 1 can be written as: U n S = — Am/n K We used three geomorphic indices including mountain front sinuosity (Smf), valley floor width-to-height ratio (Vf), and asymmetry factor (AF), together with longitudinal stream profiles and hypsometric curves for the main catchments of the Dinarkooh region calculated and extracted from Digital Elevation Model (DEM). (4) that ksn is normalized steepness index. This equation gives uplift rate for the area with steady state landscape by choosing appropriate values of m, n and K. after logarithmic regression, analysis of area and slope values, concavity and steepness values were calculated and by using their values in equation 4, uplift rate is calculated. Constant values of n and K is obtained from previous studies (Tucker & Slingerland, 1996; Wobus & alii, 2006). Because of importance of knickpoint selection in understanding landscape responses to tectonics, these points were selected in stream longitudinal profile based on change in slope and concavity. Selected points (illustrated as lozenge) can be viewed in longitudinal profiles shown in figures 4, 5, 6 and 7 respectively for stream numbers 1, 2, 3 and 4. (5) that Lmf is the length of the mountain front along the foot of the mountain, i.e., the topographic break in the slope, and Ls is the length of the mountain front measured along a straight line. This index has been used to evaluate the relative tectonic activity along mountain fronts (Bull & McFadden, 1977; Keller & Pinter, 2002; Silva & alii, 2003; Pérez-Peña & alii, 2010). When a mountain front is active, uplift is more than erosion, led to straight front with low Smf value. In less active mountain fronts, erosion rate is more than uplift rate, leading to sinusoid and irregular fronts, so Smf increased. Some studies proposed that the values of the Smf index lower than 1.4 are indicative of tectonically active fronts (Keller, 1986; Silva & alii, 2003). Valley floor width-to-height ratio (Vf ) Valley floor width-to-height ratio (Vf ) (Bull & Mc Fadden 1977) is a geomorphic index for distinguishing V-shaped and U-shaped valleys. This index is defined as: 2Vfw Vf = —————— Eld + Erd – 2Esc (6) that Vfw is the width of the valley floor, Eld and Erd are elevations of the left and right valley divides, respectively, and Esc is the elevation of the valley floor. Deep V-shaped valleys (Vf <1) are a sign of linear, active downcutting streams, that shows areas subjected to active uplift, while flat-floored valleys (Vf >1) indicate an inactive streams and steady state areas (e.g. Keller & Pinter, 2002; Bull, 2007). This index has been applied to mountain fronts of Dinarkooh region. Asymmetry factor (AF) The asymmetry factor (AF) of basins was used to detect possible tectonic tilting at the basin scale. The AF is defined as below (Keller & Pinter, 2002): A AF = —R × 100 AT (7) 63 that AR is the area of the basin to the right (facing downstream) of the main stream, and AT is the total area of the drainage basin. Values of AF above or below 50 indicate that the basin is asymmetric. In order to avoid possible confusions between the catchments located in the northern and southern slopes, we expressed AF as the absolute value minus 50 in table 1. AR × 100 AF = 50 – ———– AT (8) We have divided AF absolute values in four classes based on Pérez-Peña & alii (2010): AF<5 (symmetric basins), AF=5–10 (gently asymmetric basins), AF=10–15 (moderately asymmetric basins), and AF >15 (strongly asymmetric basins). AF values in the eastern and western parts of the Dinarkooh region shows moderate to strong asymmetries. In the central part of the Dinarkooh region, basins are gently asymmetric. sion are specified by S-shaped curves, and concave curves specify relatively «old» highly eroded regions. The area below the hypsometric curve is known as the hypsometric integral (HI), varying from 0 to 1, with values close to 0 in highly eroded regions and values close to 1 in weakly eroded regions. The shape of the hypsometric curves (and the HI values) also provides valuable information about the tectonic, climatic, and lithological factors controlling catchment landscape (Moglen & Bras, 1995; Willgoose & Hancock, 1998; Huang & Niemann, 2006). We calculated hypsometric curves for four main basins with the aid of an ArcGIS extension (Pérez-Peña & alii, 2009b). The hypsometric curves show differences between the curves of the eastern, central and western parts of the region (fig. 3). HYPSOMETRIC CURVES A curve that shows the distribution of area and altitude within it in a basin is called hypsometric curve (Strahler, 1952). In this study, the hypsometric curves were drawn by plotting the relative area (0–1) above each relative height (0–1). A useful characteristic of these curves is that basins of different sizes can be compared, since area and elevation are plotted as functions of total area and total elevation (Keller & Pinter, 2002; Pérez-Peña & alii, 2009a, c; Pérez-Peña & alii, 2010). The shape of this curve is related to the degree of dissection of the basin, i.e., its erosional stage. Convex hypsometric curves specify relatively «young» lowly eroded regions, regions with moderate eroFIG. 3 - Hypsometric curves of four main streams of study area. Curves have been calculated using a 15-m DEM and CalHypso ArcGIS module (Pérez-Peña & alii, 2009b). For basin number refer to figure 2. TABLE 1 - Values of Vf (valley floor width-to-height ratio) for 16 points in main streams (presented in fig. 2) and AF (asymmetry factor) for four main basins of the Dinarkooh Region Basin Number Point of measurment Vfw Eld Erd Esc Vf AF 1 110 150 75 65 70 1240 1150 920 710 525 1220 1140 920 720 525 1160 1000 870 645 430 1.57 1.03 1.5 0.46 0.36 18 1 1 2 3 4 5 6 7 8 9 75 100 50 95 1150 980 850 690 1150 980 850 680 1050 900 800 600 0.75 1.25 0.5 0.4 7 2 75 105 50 40 1170 1050 890 695 1160 1000 890 700 1100 950 850 675 1.15 0.52 0.62 0.26 6 3 10 11 12 13 14 15 16 55 100 50 1040 1000 775 1020 1000 760 990 900 740 1.37 1 0.9 12 4 64 RESULTS AND DISCUSSION The geomorphic indices presented in this paper suggest that the Dinarkooh region is tectonically active, that more uplift occurs along its central and southern mountain fronts, where Smf and Vf present the lowest values (fig. 2 and tables 1 and 2). The principal aim of tectonic geomorphology is to extract tectonic information from the longitudinal profiles and geomorphic indices. Tectonic information of such stream profiles lies in the knickpoints and Strahler order of streams. As the stream responds to tectonic forces or lithologic changes, knickpoints location moves downward or upward in the stream. By using stream power law the data of steepness and concavity indices mostly give similar information, because of changing between two different steepness values is normally interleaved by a zone of very high or low concavity. Generally low concavity value of a stream shows increasing incision rate or lithological changes. The knickpoints sharpness gives relative information about TABLE 2 - Smf values for the different mountain front segments. Mean values for each main front are also indicated Mountain Front Segment No. Smf Mean Smf North 1 2 3 4 5 1.41 1.50 1.60 1.40 1.38 1.76 South 6 7 8 9 10 1.31 1.29 1.06 1.10 1.23 1.20 recent tectonics activity. In general, the sharper knickpoints indicate more recent activity (Wobus & alii, 2006). We have studied four main streams using stream power law. The analysis of four main streams, i.e., the Meymeh river (stream No. 1) in western part, streams 2 and 3 in central part and stream 4 in eastern part is discussed here in detail. The stream profile analysis of the Meymeh river is shown in figure 4. This is a four segment stream. Three knickpoints shows tectonic activity. All the knickpoints show the presence of local faults. Three trends observed in this stream based on morphologic conditions, i.e., an upper segment, middle segment and lower segment. The upper segment passed on relict landscape with steepness index 67.98 and uniform concavity index 0.42, which means that it suffer moderate erosion. The middle segment shows intermediate concavity 0.17 and steepness 73.73, which means that erosion process are active. The lower segment suggests higher concavity and steepness indices, i.e., 0.64 and 372.51. As the stream goes down, the sharp change in the geomorphic indices shows gradual changes in lithology and tectonic activity. The eastern part of the region has low steepness values, and because steepness is directly related to uplift rate, it means that the region underwent less deformation processes on the eastern section. We studied streams 2, 3 and 4 from central part to understand the tectonic control on drainage behavior, shown in figures 5, 6 and 7. The morphology of all the streams consists of three segments which separated by knickpoints. The first seg- FIG. 4 - Stream profile analysis of the Meymeh River (stream No. 1). It clearly shows that the three main knickpoints and three clear segments are identified. This helps us separate the Northern, Southern and Central Dinarkooh. FIG. 5 - Stream profile analysis of Stream 2 from central Dinarkooh. It clearly shows that the location of some local faults is identified by the three main knickpoints. 65 FIG. 6 - Stream profile analysis of Stream 3 from central Dinarkooh. It is a three segment profile showing less variation in steepness. FIG. 7 - Stream profile analysis of Stream 4 from eastern Dinarkooh. It clearly shows that the location of some local faults is identified by the three main knickpoints. ment of stream 2 shows relict landscape with low erosion, but after crossing a local fault it shows high concavity and steepness indices. Stream 2 is flowing in central part and has higher concavity values from 0.35 to 1.16 and steepness values from 62.24 to 106.94. Since the values of steepness are directly related to uplift, comparing these values to those of stream 1 we can conclude that the central part is more deformed and is uplifting, whereas eastern part is more stable. The concavity and steepness values are shown in table 3. This table shows normalized steepness and concavity in the upper, middle to lower segments, and variability of concavity indices in the middle segments and normalized steepness indices in the upper segment. The normalized steepness index is calculated with a fixed mean concavity value of 0.45. The streams No. 3 and No. 4 also show higher uplift rates in their middle segments. By applying stream profile analysis on four main streams of the basins and calculating the concavity and steepness values, we calculated uplift rates in different parts of the region (fig. 8). For using stream profile analysis to determine uplift rates, we assume that region is in steady state 66 TABLE 3 - Steepness and concavity values Stream No. Segment No. Concavity Steepness 1 1 1 2 2 2 3 3 3 4 4 4 1 2 3 1 2 3 1 2 3 1 2 3 0.42 0.17 0.64 1.16 0.89 0.35 0.13 0.44 0.03 0.18 0.30 0.10 67.98 73.73 372.51 72.02 62.24 106.94 142.32 63.27 175.17 111.50 72.64 160.65 (Shahzad & alii, 2009). The uplift rate map shows the amount of uplift per year in different parts of the region. In the eastern section the uplift rate ranges from 0.622 mm/yr to 1.11 mm/yr, in the central section from 0.633 to 1.75 mm/yr and in the western section from 1.10 to 3.72 REFERENCES FIG. 8 - Uplift rate map of the area showing uplift values (cm/yr). mm/yr. This suggests that the central and to some extent western parts have been experiencing more uplift compared to the rest of the region. As shown in this map, the southern part of the region has greater uplift rate value that indicates more tectonic activity. Blind thrust faults beneath this region may have a role in this activity (Berberian, 1995). CONCLUSION The geomorphic indices presented in this paper show that Dinarkooh region in Zagros mountain range is tectonically active. Mountain front sinuosity (Smf) and river incision (Vf) indicates activity in central and southern mountain fronts, and the moderate activity in northern fronts. These central and southern mountain fronts are associated with active NW-SE thrust. The northern front is associated with an inactive limb of Samand anticline. The asymmetry indices calculated for the main basins suggest the presence of active NW-SE oriented folds in Dinarkooh region and the main activity is concentrated in central parts. The hypsometric curves and the longitudinal stream profiles suggest a higher tectonic activity in the central and southern parts of the Dinarkooh region, however any of basins don’t show “High” activity, but moderate and low values are observed. Also, hypsometric curves show, along with Smf and Vf, an intermediate activity of northern mountain fronts. Digital elevation model (DEM) is an essential material for computer-based analysis of river profiles and drainage basins as it provides elevation information for the land surface. In this study we applied tectonic geomorphology analysis on the four main streams in the Dinarkooh region to study their behavior. Tectonics and subsurface lithology cause changes in the course of streams. Any change in tectonics of the region influence on drainage network development. This study can be improved by using other geological information. BENEDUCE P., FESTA B.V., FRANCIOSO A.R., SCHIATTARELLA A.M. & TROPEANO A.M. (2004) - Conflicting drainage patterns in the Matera Horst Area, southern Italy. Physics and Chemistry of the Earth, 29, 717-724. BERBERIAN M. & KING G.C. (1981) - Towards a Paleogeography and Tectonic Evolution of Iran. Canadian Journal of Earth Sciences, 18, 210-265. BERBERIAN M. (1995) - Master «Blind» thrust faults hidden under the Zagros folds: Active basement tectonics and surface morphotectonics. Tectonophysics, 241, 193-224. BISHOP P. (2007) - Long-term landscape evolution: linking tectonics and surface processes. Earth Surface Processes and Landforms, 32, 329-365. BISHOP P., HOEY T.B., JANSEN J.D. & LEXARTZA ARTZA I. (2005) - Knickpoint Recession Rate and Catchment Area: The Case of Uplifted Rivers in Eastern Scotland. Earth Surface Processes and Landforms, 30, 767-778. BULL W.B. (1977) - Tectonic geomorphology of the Mojave Desert, California. U.S. Geological Survey Contract Report 14-0-001-G-394. Office of Earthquakes, Volcanoes, and Engineering, Menlo Park, California, 188 pp. BULL W.B. (2007) - Tectonic Geomorphology of Mountains: A New Approach to Paleoseismology. Wiley-Blackwell, Oxford, 328 pp. BULL W.B. (2009a) - Tectonically Active Landscapes. Wiley-Blackwell, Oxford, 326 pp. BULL W.B. (2009b) - Geomorphic Responses to Climatic Change. Blackburn Press, NewJersey, 326 pp. BULL W.B. & MCFADDEN L.D. (1977) - Tectonic geomorphology north and south of the Garlock fault, California. In: Doehering D.O. (Ed.), «Geomorphology in Arid Regions. Proceedings at the Eight» Annual Geomorphology Symposium. State University of New York, Binghamton, NY, 115-138. CAPOLONGO D., CECARO G., GIANO S.I., LAZZARI M. & SCHIATTARELLA M. (2005) - Structural control on drainage network of the southwestern side of the Agri River upper valley (Southern Apennines, Italy). Geografia Fisica e Dinamica Quaterenaria, 28, 169-180. CLOETINGH S. & CORNU T. (2005) - Surveys on environmental tectonics. Quaternary Science Review, 24, 235-240. HOMKE S., VERGES J., EMAMI H., GARCES M. & KARPUZ R. (2004) - Magnetostratigraphy of Miocene Pliocene Zagros foreland deposits in the front of the Push-e Kush Arc (Lurestan Province, Iran), Earth and Planetary Science Letters, 225, 397-410. HOWARD A.D. (1994) - A Detachment-limited Model of Drainage Basin Evolution. Water Resources Research, 30, 2261-2285. HUANG X.J. & NIEMANN J.D. (2006) - An evaluation of the geomorphically effective event for fluvial processes over long periods. Journal of Geophysical Researches-Earth Surface, 111, F03015. KELLER E.A. (1986) - Investigation of active tectonics: use of surfacial earth processes. Active Tectonics National Academy Press, Washington D.C. KELLER E.A. & PINTER N. (2002) - Active Tectonics. Earthquakes, Uplift, and Landscape. Prentice Hall, New Jersey, 362 pp. KELLER E.A., SANZ DE GALDEANO C. & CHACON J. (1996) - Tectonic geomorphology and earthquake hazard of Sierra Nevada, Southern Spain. 1ª Conferencia Internacional Sierra Nevada. Publicaciones Universidad de Granada, Granada, 201-218. KELLER E.A., SEAVER D.B., LADUZINSKY D.L., JOHNSON D.L. & KU T.L. (2000) - Tectonic geomorphology of active folding over buried reverse faults: San Emigdio Mountain front, southern San Joaquin Valley, California. Geological Society of America Bulletin, 112, 86-97. MAROUKIAN H., GAKI-PAPANASTASSIOU K., KARYMBALIS E., VOUVALIDIS K., PAVALOPOULOS K., PAPANASTASSIOU D. & ALBANAKIS K. (2008) Morphotectonic control on drainage network evolution in the Perachora Peninsula, Greece, Geomorphology, 102, 81-92. 67 MOBASHER K. (2007) - Kinematic and Tectonic Significance of the fold and fault related fracture systems in the Zagris Mountans, Southern Iran, Ph.D. Thesis, Georgia State University, Georgia. MOGLEN G.E. & BRAS R.L. (1995) - The effect of spatial heterogeneities on geomorphic expression in a model of basin evolution. Water Resource Researches, 31, 2613-2623. MONTGOMERY D.R., ABBE T.B., BUFFINGTON J.M., PETERSON N.P., SCHMIDT K.M. & STOCK J.D. (1996) - Distribution of Bedrock and Alluvial Channels in Forested Mountain Drainage Basin. Nature, 381, 587-589. MUMIPOUR M. & NEJAD H.T. (2011) - Tectonics Geomorphology Setting of Khayiz Anticline derived from GIS processing, Zagros Mountains, Iran. Asian Journal of Earth Sciences, 4, 171-182. O’CALLAGAN J.F. & MARK D.M. (1984) - The Extraction of Drainage Networks from Digital Elevation Data. Computer Vision, Graphics & Image Processing, 28, 323-344. PEREZ-PENA J.V., AZANON J.M., AZOR A., TUCCIMEI P., DELLA SETA M. & SOLIGO M. (2009a) - Quaternary landscape evolution and erosion rates for an intramontane Neogene basin (Guadix-Baza basin, SE Spain). Geomorphology, 106, 206-218. PEREZ-PENA J.V., AZANON J.M. & AZOR A. (2009b) - CalHypso: an ArcGIS extension to calculate hypsometric curves and their statistical moments. Applications to drainage basin analysis in SE Spain. Computers & Geosciences, 35, 1214-1223. PEREZ-PENA J.V., AZANON J.M., AZOR A., DELGADO J. & GONZALEZLODERIO F. (2009c) - Spatial analysis of stream power using GIS: SLk anomaly maps. Earth Surface Processes and Landforms, 34, 16-25. PEREZ-PENA J.V., AZANON J.M., BOOTH-REA G., AZOR A. & DELGADO J. (2009d) - Differentiating geology and tectonics using a spatial autocorrelation 3 technique for the hypsometric integral. Journal of Geophysical Researches-Earth Surface, 114, F02018. PEREZ-PENA J.V., AZOR A., AZANON J.M. & KELLER E.A. (2010) - Active tectonics in the Sierra Nevada (Betic Cordillera, SE Spain): Insights from geomorphic indexes and drainage pattern analysis. Geomorphology, 119, 74-87 RIBOLINI A. & SPAGNOLO M. (2008) - Drainage network geometry versus tectonics in the Argentera Massif (French-Italian Alps). Geomorphology, 98, 253-266. 68 SEPEHR M. & COSGROVE J.W. (2005) - Role of the Kazerun fault in the formation and deformation of the Zagros Fold-Thrust Belt, Iran. Tectonics, 24, 1-13. SHAHZAD F., MAMOOHD S.A. & GLOAGUEN R. (2009) - Drainage Network and Lineament Analysis: An Approach for Potwar Plateau (Northern Pakistan). Journal of Mountain Science, 6, 14-24. SHAHZAD F. & GLOAGUEN R. (2011) -TecDEM: A MATLAB based toolbox for tectonic geomorphology, Part 1: Drainage network preprocessing and stream profile analysis. Computers & Geosciences, 37, 250260. SILVA P.G., GOY J.L., ZAZO C. & BARDAJI T. (2003) - Fault-generated mountain fronts in southeast Spain: geomorphologic assessment of tectonic and seismic activity. Geomorphology, 50, 203-225. SNYDER N.P., WHIPPLE K.X., TUCKER G.E. & MERRITS D.J. (2000) Landscape Response to Tectonic Forcing: Digital Elevation Model Analysis of Stream Profiles in the Mendocino Triple Junction Region, Northern California. Bulletin of the Geological Society of America, 112, 1250-1263. STOCKLIN J. (1968) - Possible Ancient Continental Margins in Iran. The Geology of Continental Margins, 873-887. STRAHLER A.N. (1952) - Hypsometric (area-altitude) analysis of ero-sional topography. Geological Society of America Bulletin, 63, 11171142. TUCKER G.E. & SLINGERLAND R. (1996) - Predicting Sediment Flux from Fold and Thrust Belts. Basin Research, 8, 329-349. WHIPPLE K.X. (2004) - Bedrock Rivers and the Geomorphology of Active Orogens. Annual Review of Earth and Planetary Sciences, 32, 151185. WILLGOSE G. & HANKOCK G. (1998) - Revisiting the hypsometric curve as an indicator of form and process in transport-limited catchment. Earth Surface Processes and Landforms, 23, 611-623. WOBUS C., WHIPPLE K.X., KIRKBY E., SNYDER N., JOHNSON J., SPYROPOLOU K., CROSBY B.T. & SHEEHAN D. (2006) - Tectonics from Topography: Procedures, Promise and Pitfalls, in Willett S.D., Hovius N., Brandon M.T. & Fisher D.M. (eds.), «Tectonics, Climate and Landscape Evolution», GSA Special Paper, 398, 55-74. (Ms. received 30 December 2011; accepted 30 April 2012)