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Khan-e Khamis structural analysis and morphotectonics based on GIS information.


Zagros mountain system in southwest Iran has been studied by plenty of geologist because of its significant role in geology of Iran. Several subdivided are suggested for this area based on difference of structural style and lithology [4,5].

Farhoudi [5], introduce 3subdivision for Zagros based on similarity that exist between Zagros and island arc:

1--Volcanic zone: is in northeast of Zagros or Oroumieh-Dokhtar volcanic belt. This belt consists of Cenozoic andesitic rocks and extending for about 2300km, from Van Lake in turkey in the west to the Bazman and Taftan in the eastern Iran and Maran in Pakistan to the east.

2--Upper slope discontinuity and depression: is introduced as a complex structural zone by Falcon [4]. This zone has 120km wide and located in southwest of volcanic belt. 5-10 km of this zone on its southwest is named crush zone which consists of sedimentary and metamorphic rocks.

3--Zagros lower slope thrust and fold belt: extended from southwest margin of second belt to Persian golf depression. Most part of this is in vicinity of second belt and its wide is 80km that named as imbricate zone. In southwest of this zone, there are many parallel anticlines and synclines. Studied area has been located in simple folded zone.

Data from simple folded zone shows that folding of this part of Zagros causes by basement faults, hidden faults, depressions and salt dams. Because of existence of these features folded and faulted Zagros is a suitable name for this region.

Farhoudi [5], suggested that, in this zone, basement is upthrusted and its dip is toward northeast.

Although these thrust are not in surface but folding of upper bed affected by them and cause to formation of asymmetric fold toward southwest.

Studied Area:

The studied area that has been located in longitude 52[degrees]00' 05" to 52[degrees]34' 02" and latitude 29[degrees] 26' 11" to 29[degrees]38' 06", is part of Zagros mountain system (fig.1). Kuh pah anticline is in 35km west of Shiraz. This zone consists of inter-mountain plains in vicinity of mountain features. These mountains are Derak (2900m), Chaharmakan (3100m), Sabzpoushan (2822m) and Kuh pahn (2300m). Kuh pahn anticline is a small one that is not similar to others (fig.2).




In this paper the structural geology of region is studied and because of close relations between structural geology and morphotectonics, some of some of morphotectonics indexes and joint pattern has been determined for this region.

2-1-Joint Pattern:


Based on joints and fractures pattern, the direction of main stress axes in this area are determined.

13 station with suitable distribution in studied area selected that are located in the same rock (fig 3). Shear joints and conjugate joints are measured (table 1).

2-2-Fold Classification:



Based on this classification Kuh pahn anticline is an asymmetric anticline (fig 4). Asymmetric fold in profile have no vertical axial surface and no mirror plane of symmetry. The limbs have unequal length and dip.

2-2-2-Inter limb Angle:


Inter limb angle for Kuh pahn anticline is 154[degrees] so it is a gentle fold (fig 5). Gentle folds, which have 120-180[degrees] inter limb angle.

To calculate the density of fractures in studied area in some stations that have plenty of systematic joints, a circle whit 5m diameter is drown and the length of each joint in this area is measured.

The density of joints for each station is equal to D = L/S (these values are shown on table3). As the value of density increases, the fracturing of rocks increases. Maximum density is belonging to the station 9 on the SW limb and the minimum density is belonging to the station 5 on the NE limb.

2-3-Kuh pahn Morphometric Indexes:

To calculate the each index, different numbers of stations are used.

[]: 10 stations

[V.sub.f]: 8 stations (fig 8)

V: 5 stations.


The result of each index is shown below.

2-3-1-Mountain Front Sinuosity ([]):

From 10 station (fig 7), the value of [] in Kuh pahn anticline vary from 1.238 to 1.682 and the mean value is 1.410(table 4).

2-3-2-Ratio of Valley-Floor Width to Valley Height ([V.sub.f]):

Based on table 5 value of this index vary from 1.02 to 2.87 for the studied area. The mean value is 2.112 that shows active tectonic for this area (fig 8). Mean value on SW limb is 2.212 and on NE limb is 2.012. So the tectonic activity on NE limb is more than SW limb.


Based on the value of [] and [V.sub.f], the studied anticline is plotted on the 2nd group of Keller & Pinter [9]; Wells et al., [13] classification.

2-3-3-V Ratio:

The V index is calculated with measuring in 16 stations and the value of this index is vary from 1.12 to 2.42 and the mean value is 1.45(table 6). The mean value on SW limb is 1.55 and the mean value on NE limb 1s 1.36 that shows tectonic activity on NE limb is more than SW one. From these results the studied anticline is plotted on the 2nd group of Bull & Mc fadden [3] classification.

2-4-Peruse of Studied Area by GIS Data:

In this method software that is used include: Envi, Arc View, GIS 9.2 and Ilwis. TM satellite image with band 5 and 7 is used to prove the map.

2-4-1-DEM Map:

This map is proved based on topographic map (1:25000) with GIS. As shown on DEM map (fig 9) Kuh pahn anticline is higher than its vicinity that is alluvial plain. The attitude of Kuh pahn anticline is 2300m.


2-4-2-Slope Map:

On 98% of anticlines in Zagros, the dip of SW limb is more than NE limb [5] so, is more affected by erosion.


In Kuh pahn anticline the topographic slope on the NE limb is high related to the rest part of studied area (fig 10). Also dip of the NE limb is more than SW limb, which is due to the thrusting.

2-4-3-Hill Shad Image:

This image is applied to show the geological structures and the pattern of channels. On this image the difference between elevations in different pars of area determined by change the color from dark (for high elevations) to light (for low elevations) (fig 11).


2-4-4-Hydrology Map:

The pattern of channel is affected by the geology, lithology, structure and topographic anomalies. In this area the pattern of channel is parallel and radial. As shown in fig12 in the crest of the anticline, channels are radial and on the limb of anticline especially on NE limb they are parallel because of the topography high. In the vicinity of anticline that is alluvial plain the pattern of channel is dendritic.



1--From morphometric indexes the studied area is active.

2--Based on morphometric indexes results the activity on NE limb of Kuh pahn anticline is more than SW one.

3--Presence of Kareh bas and Sabz poushan faults verify the activity of region.

4--The axis of anticline is displaced by the Kareh bas fault that causes to increasing in Kuh pahn anticline attitude.

5--Based on rose diagrams, type of joint in both limb of anticline is tension-shear.

6--Peruse of anticline shows that, it is an asymmetric fold and dip of NE limb is more than SW limb.

7--Because of vast extension of Asmari and Jahrom formations that are excellent water source, there are a lot of farms which the presence of joints caused to penetrate of water to the ground, so the region is a good topic for hydrogeology.


[1.] Arian, M. and A. Ahmadnia and M. Qorashi and M. Pourkermani, 2002," Structural Analysis of Mengharak Transcurrent Fault System in Zagros", Iran. Special Geo. 2002 Conference Issue Geoarabia, 7(2): 209-210.

[2.] Berberian, M., 1995, "Master blind thrust faults hidden under the Zagros fold: Active basement tectonics and surface Morphotectonics", Tectonophysics, 241: 193-224.

[3.] Bull, W.B. and L.D. Mcfadden, 1977," Tectonic geomorphology north and south of the Garlock fault", California, Proceeding of the 8th Annual Geomorphology Symposium, New York.

[4.] Falcon, N.L., 1974," Southern Iran: Zagros mountain in Mesozoic--Cenozoic organic belt", Geol. Soc. London Spec. Pub., 4: 199-211.

[5.] Farhoudi, G., 1978, "A comparison of Zagros geology to island arcs", J. Geol., 86: 323-334.

[6.] Granja Bruna, J.L. and ten U.S. Brink and A. Carbo-Gorosabel and Munoz-Martin. A. and Gomez Ballesteros. M., 2009. "Morphotectonics of the central Muertos thrust belt and Muertos Trough (northeastern Caribbean)". Marine Geology, 263: 1-4, 15 July2009, Pages 7-33.

[7.] Hessami, K. and H.A. Koyi and C.J. Talbot, 2001, "The Significance of strike slip faulting in the basement of the Zagros fold and thrust belt. Journal of petroleum geology", 24(1): 5-28.

[8.] Hessami, K., 2002," Tectonic History and Present--Day Deformation in the Zagros Fold--Thrust Belt", ACTA Universitatis Upsaliensids, Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 700: 13 P.P. Uppsala.

[9.] Keller, E.A. and N. Pinter, 2002, "Active tectonics", New York prentice Hall Inc.

[10.] Smith, B. and C. Auborg and, Guezou and J.c., Nazari and M. Molinaro and X. Braud and N. Guya, 2005," Kinematics of a sigmoidal fold And vertical axis rotation in the east the Zagros-Makron syntaxis (southern Iran): paleomagnetic, magnetic Fabric and microtectonic approaches",Techtonophisics., 411: 89-109.

[11.] Solaymani Azad, S. and J. Francois Ritz and M. Abbassi, 2010." Left-lateral active deformation along the Mosha-North Tehran fault system (Iran): Morphotectonics and paleoseismological investigations". Tectonophysics, In Press, Accepted Manuscript, Available online 27 September 2010.

[12.] Stoneley, R., 2005,"The Zendan Fault of southern Iran, Proceedings of the Geologists", Association, 116: 311-313.

[13.] Wells, S.G. et al., 1988, "Regional variation in tectonic geomorphology analog a segmented convergent plate boundary pacific coast of Costa Rica", Geomorphology, 1: 239-269.

(1) Mahdi Mashal, (2) Tahereh Rafiee, (3) Ghodrat allah Farhoudi, (4) Sanaz Seyedi Sahebari, (5) Shima Rahmati Kamel

(1) Department of Geology, North Tehran Branch, Islamic Azad University, Tehran, Iran.

(2) Department of Geology, Shiraz Branch, Islamic Azad University, Shiraz, Iran.

(3) Department of Geology, Shiraz Branch, Islamic Azad University, Shiraz, Iran.

(4) Department of Geology, North Tehran Branch, Islamic Azad University, Tehran, Iran.

(5) Department of Geology, North Tehran Branch, Islamic Azad University, Tehran, Iran.

Corresponding Author

Mahdi Mashal, Department of Geology, North Tehran Branch, Islamic Azad University, Tehran, Iran.

Tel: +98-9166147065. E-mail address:
Table 1: Direction of joints on limbs of anticline.

SW Limb

Direction          Joint           St. No

N35E, N50W         Tension-shear

N30E, N60W         Tension-shear
N50E               Tension         8
N15E               Shear
N60E, N50W         Tension-shear   9
N30E               Shear-tension
N50E               Tension
N15E               Shear
N60E, N60W         Tension-shear
N70E               Shear-tension   10
N40W, N40E         Tension
N40E               Tension-shear   11
N30E               Shear-tension
N30W               Shear Shear
N60E               Tension-shear   12
N0E                Shear-tension
N10E               Shear
N80E, N35E, N55W   Tension-shear
N08E               Shear-tension   13
N15E               Shear

NE Limb

Direction          Joint           St. No

N25W               Tension-shear   1
N52E               Tension
N70E               Shear

N30W, N45E N70E    Tension         2

N25W, N48W,N40E    Tension-shear   3

N20W, N65E         Tension-shear   4
N40W               Tension
N70E               Shear
N25W, N65W         Tension- shear  5
N15E               Shear

N0W, N20W          Tension-shear   6
N45E               Shear

Table 2: cline.

Dip      Strike   Fold Elements

84SW     N42W     Axial plane
Plunge   N49E     a-axis
09       S40E     b-axis
80       N72W     c-axis

Table 3: Result for joint measurement.

Station no.   Joint    Area   Joint
              length          Density

St 1 (NE)     43.95    78.5   0.5598
St 2 (NE)     30.3     78.5   0.3859
St 5 (NE)     26.6     78.5   0.3388
St 7 (SW)     78       78.5   0.9936
St 9 (SW)     106.2    78.5   1.3528

Table 4: Results of [] index.

Front   [] (km)   [L.sub.s] (km)   []

1       1.7               1.05             1.619
2       1.85              1.275            1.45
3       2.65              1.575            1.682
4       1.862             1.425            1.306
5       1.932             1.45             1.332
6       2.055             1.55             1.325
7       1.85              1.35             1.37
8       2.175             1.725            1.26
9       1.95              1.575            1.238
10      2.9               1.8              1.611

Table 5: Results of [V.sub.f] index.

Valley   [V.sub.fw] (m)   [E.sub.ld] (m)   [E.sub.rd] (m)   [V.sub.f]
No.                                                         ratio

1 SW     180              2060             2080             2.25
2 SW     250              2040             2100             1.56
3 SW     170              1570             1500             2.12
4 SW     220              1540             1570             2.75
5 SW     250              1410             1560             2.38
6 NE     115              1830             1830             2.87
7 NE     300              1800             1610             1.93
8 NE     200              1930             1850             2.67
9 NE     143              2030             2060             1.02
10 NE    305              1620             1730             1.57

Table 6: Result of V index.

St.     [A.sub.v]     [A.sub.c]     V
        ([m.sub.2])   ([m.sub.2])   ratio

1 SW    5235          3300          1.58
2 SW    6857          5708          1.20
3 SW    6002          5082          1.18
4 SW    2124          1242          1.71
5 SW    5040          3927          1.28
6 SW    5653          3924          1.44
7 SW    6859          4301          1.59
8 SW    4934          2031          2.42
9 NE    9007          7020          1.28
10 NE   5750          4243          1.35
11 NE   11875         9533          1.24
12 NE   4854          3173          1.52
13 NE   3200          2141          1.49
14 NE   8548          5924          1.44
15 NE   6583          4351          1.51
16 NE   6054          5380          1.12
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Article Details
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Author:Mashal, Mahdi; Rafiee, Tahereh; Farhoudi, Ghodrat allah; Sahebari, Sanaz Seyedi; Kamel, Shima Rahmat
Publication:Advances in Environmental Biology
Article Type:Report
Geographic Code:7IRAN
Date:Jul 1, 2012
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