علی سلگی

It seems that the study and investigation of topographical landforms and the pattern of the drainage network system, based on geomorphic indicators, can evaluate the status of active tectonic performance. However, the basic structure of the earth, the type of rock and the local factors that determine the microclimate are not taken into consideration. Asymmetry factor (AF) is used to measure the asymmetry of the drainage basin. This research was conducted with the aim of evaluating the tectonic activity of Golpayegan area using the asymmetry index of the drainage basin. The scope of this research is located in the Golpayegan area and in the structural zone of Sanandaj-Sirjan. The results obtained from the research show that Gudjan, Shah Enayat, Hazar Jarib Gharbi, Chehlkhane, Vanshan Gharbi and Vanshan basins are classified in tectonic class 1 and the rest of the basin in class 2 (moderate) to class 3 (relative tectonic activity) below) are shown. The calculated values ​​of the transverse topographic symmetry index are in good agreement with the calculated values ​​of the asymmetry index, and the values ​​related to the asymmetry index confirm well the values ​​of the transverse topographic symmetry.

The Hossein Abad area is located 120 km southeast of Zanjan. The volcanic rocks in this area belong to Eocene and younger a ges. Volcanic rocks include dacitic, trachyandesite and andesitic lavas, as well as tuff. Volcanic rocks have quartz, alkali feldspar, abundant plagioclase, pyroxene and amphibole. The alkali feldspar is Sanidine and plagioclases are oligoclase and andesine. The Porphyritic, microlithic porphyritic, glomeroporphyritic and poikilitic textures are predominant in these rocks. Examining the mineral chemistry of rocks in the study area shows that the clinopyroxenes are diopside and augite. Amphiboles in these rocks are magmatic and calcic with the chemical composition of pargasite. Based on magmatic diagrams, rocks in studied area are alkaline. According to the thermobarometric diagrams, these rocks have formed at temperature and pressure ranges of 700-750℃ and 5-6.5 kbar respectively. These values correspond to the depth of middle-lower crust. The rocks are formed in the active continental margin.

The Zagros fold-thrust belt's Fars region is crucial for the placement of enormous gas reserves in Permo-Triassic carbonate sediments. Therefore, it's important to investigate the potential impact of the Hendurabi fault on the expansion of hydrocarbon traps in the inner Fars region. This will help advance the exploration goals of hydrocarbon materials. The study area is located in the inner Fars region of the Zagros thrust belt. In this research, maps of equal thickness have been prepared, analyzed, and evaluated based on drilling well data in the region, using ArcGIS software. Given the importance of changes and evolutions of the hydrocarbon system in the exploration of hydrocarbon resources, the function of the main basement faults with the role of controlling the bottom of the sedimentary basins, along with the changes that have occurred, can change the nature of a hydrocarbon system and the created hydrocarbon traps. Overall, the activity of the Hendurabi fault has caused thickness changes on the sides of the fault, confirmed by the uplifts and subsidence’s created on the sides of the Hendurabi fault at the same time as the deposition of some formations such as Dashtak. The activity of this fault as a controlling fault of the sedimentary basin floor during the sedimentation of formations like Dashtak is confirmed. Based on the obtained results, the southeastern area of the studied area, containing hydrocarbon traps, is suitable for exploration due to the adequate and appropriate thickness and suitable depth of the Kangan reservoir horizon and Dashtak caprock.

Shurijeh Formation is deposited in Kopeh Dagh sedimentary basin, and it is one of the gas reservoirs in northeastern Iran. Khangiran gas field with a northwest-southeast structure is located in the northeastern part of Khorasan Razavi province. The purpose of this study is to investigate facies, sedimentary environment and diagenetic processes that have been effective on the reservoir quality of Shurijeh Formation in the studied wells. Based on petrographic studies on thin sections of Shurijeh Formation in the studied wells, nine main rock facies including Sandy Conglomerate, Quartz Arenite, Sublitarnite, Subarcose, Quartz Wackes, Claystone/Shale, Nodular Anhydrite, Sandy Dolomudstone and Sandy Dologrenston have been identified that are located in the tidal, river, flood plain and meandering sedimentary zones. Petrographic studies of thin microscopic sections show that diagenetic processes in three marine, meteoric and burial environments have affected the Shurijeh Formation. The primary processes affected in the facies of Shurijeh Formation include cementation, bioturbation, primary dolomitization and anhydrite. Finally, using image log, petrophysical log and combining the results of thin section studies in the key well of Khangiran field, was determined that in most cases there is a good conformity between the results of image log, thin sections and petrophysical log.

The southern section of the Caspian Sea convexity is included in the Central Alborz, which stretches from Semnan to Qazvin. The Central Alborz zone is the focus of the research because of the strong association between lead and zinc mineralization and tectonics, as well as the great potential of this zone. The major horizons of lead and zinc mineralization, as well as the location of these horizons with orogenic events, have been investigated in this study, based on fieldwork and office studies as well as previous research. According to this research, there are eight lead and zinc mineralization horizons in Central Alborz, ranging from old to recent, including the mineralization horizon of Soltanieh Formation associated with Zaygonin orogeny, the mineralization horizon of Mila Formation associated with Caledonian orogeny, the mineralization horizon of Mubarak Formation With Alborz orogeny, Mineralization horizon of Ruteh Formation related to Hercynian orogeny, Mineralization horizon of Elika Formation related to Early Cimmerian orogeny, Mineralization horizon of Lar Formation related to Middle Cimmerian orogeny, Cretaceous mineralization horizon related to Laramid orogeny and Mineralization within the Karaj Formation is related to the Eocene age in the Pyrenean orogen. According to mathematical modeling in the Central Alborz area, the lead and zinc mineralization controls by thrust faults and reverses-strike slip faults. According to the findings of this study, more than 60% of mineralizations connected to structures occur in the Mesozoic. Triassic mineralizations occurred along with extention tectonics, while Cretaceous mineralizations formed under a compressive regime.

Existence of seismic activity history and high rate of tectonic activity in the region, which indicates that the study area is releasing energy in the pre-seismic stage and as a result in some points of stress accumulation, which will lead to high seismic potential in the future. For this purpose, the active faults of the study area have been drawn and the scatter map of the relative tectonic activity level has been evaluated with instrumental seismic data. Finally, the maximum seismic acceleration of the area has been calculated and the area lines have been obtained by PCA method. After examining the area lines, it was found that lines L1, L2, L3, L4, L5 do not have a counterpart in the aerial magnetic map and therefore are a surface fault. L6 has good compatibility with F-9 magnetic line and surface lines L2, L3, L4, L5 do not have any compatibility with any of the faults exposed in the geological map and magnetic line and their faulting needs to be investigated. It has a desert.

The Shemshak Group contains a rich and diversified flora in the Abyek and Jirande areas (western Alborz). This paper considers the description of ferns and horsetails from this flora and their ecological significance. The study revealed the occurrence of five species of Equisetales, seven species of Filicales, and two species of Marattiales; among these, two genera and five species are recorded for the first time from Iran. Moreover, two species are recorded as new to the western Alborz. The studied horizon in the Abyek area represents a Rhaetic delta lowland. Monospecific thickets of Equisetites muensteri, Clathropteris meniscioides, and Dictyophyllum nathorsti were extended across large regions of the lowland, providing an accessible source of food for sauropods. The studied horizon in the Jirande area is Liassic in age, well developing in parts of delta lowland and delta upland sub-environments; the different parts of these sub-environments were covered by monospecific thickets of Equisetites laevis, Schizoneura paradoxa, Neocalamites hoerensis, N. ishpushtensis, Clathropteris obovata, Dictyophyllum exile, D. nathorsti, and Thaumatopteris brauniana, forming a significant food source for sauropods, while drier habitats within the delta were occupied by Symopteris pseudolobifolia and Marattiopsis barnardii , which had a less important role in sauropod’s diet.

The study area is located in the northern part of Jask, southeastern Hormozgan. The drainage basin is of ​​the North-South trend and mostly except for one case that flows into the Strait of Hormuz, the rest flows into the Oman Sea and the main ones are Bahmadi and Tabarkan Rivers. From a geomorphological point of view, the study area can be divided into two parts, the high part near the fault and the low part that flows into the deltas of the Oman Sea and the Strait of Hormuz. The highest points in the region are Mount Riman, Samuki, Perke and Mubarak. The most important geomorphological controlling factors in the Jask area are the type of rock units, structural features, deformed landforms, and erosive activities due to the greater weakness of rock units and their lithological compositions, which cover large parts of the area as low and eroded lands. The erosional activities in the southern part, which mostly composed of marl, is much higher than the northern part, and the impact of the Zendan Fault in the erosion, followed by floods and landslides, is very evident.

The area is one of the most hazardous areas in the South Iran due to its location on the border between two plates of Zagros and Makran, and the compressional stress caused by the movement of these two plates. So, to better understand and identify, prevent and deal with natural disasters and hazards, in this study using the geomorphological indices of SL, Smf, Vf, Af, T, Bs and Iat, which determine the tectonic conditions prevailing in each region, the high-risk points in terms of geodynamic processes occurring on the area and the impact of the Zendan Fault on these indicators are discussed. 

A set of several geomorphic indices can be used to study the relative active tectonics. These indicators can be used as a quantitative method to study geomorphology related to erosional and sedimentation processes in the river channel, longitudinal profile and morphology of the river valley, or tectonic features such as fault escarpment. Tectonic indicators are able to determine the different zones created as a result of local change in tectonic activity. In this research, several geomorphic indices in the basins of the Jask region were investigated and the results of each index were analyzed based on the values ​​obtained for that index. The various geomorphic indices mentioned in the above section in relative tectonics (Iat) were divided into four categories: very high activity, high activity, medium activity, low activity. By calculating the average class category of indices (S / n) in each basin and evaluating it by the method [3], the relative tectonic index (Iat) was divided into four class categories. In this classification, category one is very high tectonic activity (S / n between 1.5 to 1), category two is high tectonic activity (S / n between 2 to 1.5), category three is medium tectonic activity (S / n is between 2.5 to 2) and category four is low tectonic activity (S / n is more than 2.5). According to this classification, the following results were obtained in the study area (table 1-1). Table 1. Tectonic activity index (IAT) in the case study area of the author 1400
 

After examining the geomorphological indices and calculating them, it was found that the study area is relatively affected by the three major tectonic phenomena of the Zendan Fault, uplift and rough topography, oceanic subduction, and the presence of soft sedimentary rocks as the value of Iat index indicates moderate tectonic activity in this region.

The Zagros suture zone is one of Key regions. Continent - Continent collision between Arabian plate and Iranian Block. This region is coincided by High Zagros and Zagros Simply Fold Zones in Western side and in other side is the Sanandaj- Sirjan Zone. The region of this research in situated in Northern part of suture zone. The Zagros suture is oriented parallel to the other collision Structures as passive and active margins of Neo- Tethys Basin and also to Magmatic Arc (Urmiyeh - Dokhtar Arc).The main Faults in this region which we can mention by name are Zagros Main Thrust Fault and Zagros Main Recent Fault, Which they are also parallel to others structures. This region of suture zone in highly deformed and structures as folds, faults and nappes are the evident of a long compression Tectonics. The aim of this research firstly is analysing of folds and secondly is calculation of shortening rate of crust in this part of collision Zone. Three structural section (Eslam Abad- e- Gharb - Mahidasht, Kamyaran and Gazorkhani) have been balanced and the rate of shortening which is obtained respectively is 6252m , 6530m and 2040m.

Particle size distribution (PSD) is one of the sediments' most important physical properties, affecting other physicochemical properties. Fractals are the objects or processes that show a similar appearance or behavior on some large, spatial, or temporal scale. Each fractal can be divided into several parts, each of which resembles the main body. Many natural phenomena and processes are based on fractal models. Loess particles maintain good self-similar properties even when modified through pedogenesis so that the fractal dimension of their particle size is considered as a new indicator of particle size. The loess sequences, produced by aeolian under the influence of past weather changes, have been transported, deposited, and undergone many changes by pedogenesis, whose information is recorded in loess particles. By studying the PSD loess, which is a natural fractal, one can discover data about the past environment. Therefore, PSD changes can be used to indicate the pedogenesis intensity and process or the soil age.Post-depositional pedogenesis, including chemical and biological weathering, causes further particle crushing, the extent of which may vary in different locations due to deposition PSD and the time and intensity of pedogenesis or some other factors. Typically, intense pedogenesis or poor to very poor sorting occurs in warm and humid climates, while poor pedogenesis occurs in cold and dry climates. Changes in the loess texture reflect its post-deposition conditions. Thus, this study sought to analyze Golestan's loess texture developments via fractal PSD for the first time, which could interpret the extent of tissue changes at different points. The results were then compared to the fractal geometry obtained from the electron microscope images.

This study was conducted in Golestan province. The study area is located at latitudes of 38° 8' to 36° 30'N and longitudes of 53° 57' to 56° 22' E. Based on three types of loess texture, including sand loess, silt loess, and clay loess, sixteen samples were totally collected from three zones. Moreover, the fractals were measured using differential box-counting and PSD. The PSD fractal was calculated by sieve-hydrometric (DbH) and laser (Dbl) methods.

The mean DbH for region 1 was 2.64  and region 2 was 2.30. DbH in region three differed in two values. For two regions S12  and S13, the values of DbH are 2.74  and 2.70 and for S 14, S15 and S16 are 2.62,1.06 and 2.24 respectively. Also, the results showed a mean of 4.37 microns and sorting is very poorly (mean φ = 2.96) for region one, a mean of 14.35  microns and sorting is very poorly (mean φ = 3.17) for region two and  a mean of 49.56 microns with two different sorting values show very poorly sorting (mean φ = 2.28) at S13 and S12 stations and sorting poorly (mean φ = 1.78) at stations S16, S15, S14  for zone three. The average fractal grain dimension in region one is 0.673  in region two is 00.788  and in region three is 0.850.. The fractal dimensions of the grain surface in region one have an average of 0.51  in region two is 0.49  and in region three is 0.50. The average value of fractal geometry of grain density arrangement (DFf) is 1.94  in region one, 1.87 in region two and 1.91 in region three.The average fractal arrangement of pore fabric density (DFp) in region one is 1.47  in region two and 1.5  in region three is 1.59.. The fractal geometry of the cement fabric density arrangement is 1.33  in region one, 1.43 in region two and 1.52 in region three.

The results of examining DbH dimensions in the loess of Golestan province show that the percentage of sand decreases and the clay content increases with the increase of DbH. Comparison of fractal with sediment textual parameters indicate that the number of sorting increases and the sorting of particle decreases with the increase of DbH. This means that the samples have a better gradation of PSD and a larger volume of particle size classes. The kurtosis index decreases with the increase of DbH and the curvature broadening increases as a result of the increase of the particle size classes.The results of examining DbL fractal dimensions in the loess of Golestan province show that the percentage of sand decreases and the silt and clay contents increase with the increase of DbL. Based on the results of laser sizing, the increased silt and clay contents lead to a better gradation of sediments. The negative trend of particle sorting against DbL means that the sorting index decreases and the particle sorting increases with the increase of DbL. The positive trend of kurtosis against DbL means that the kurtosis index increases and the curvature broadening decreases with increase of DbL.Three stations of AlmaGol, AlaGol and Agh Ghala Belt in zone 3 had lower DbH and DbL, better sorting, and the highest median size. This may be due to the differences in the sediments’ origins or forming environment and retransfer. This implies that the fractal values ​​can be useful for identifying the transfer mechanism in different sediments.The fractal geometry changes with the changes in loess texture. Therefore, a higher fractal dimension content indicates a higher soil formation and higher fine particle ratios. According to the results, if particle distribution is well graded, it can be claimed that fractal geometry demonstrates the changes after loess deposition. According to the fractal results obtained from electron microscope images in Golestan loess, the fractal dimensions of the grain increased with the increase of diameter. This confirms that near the source, grains are deposited with higher order and away from the source, the fractal number becomes smaller as the grain size decreases. The fractal dimensions of the grain decrease with the increase of particles roundness from zone 3 (near the source) to zone 1 (away from the source). This implies that the sedimentss order decreases and the texture undergoes less changes with the increase of particles roundness. On the other hand, the fractal grain dimensions increase with the increase of sphericity. Since the sphericity decreases from zone 3 to zone 1, the fractal number of grain dimensions decreases. This means that a higher sphericity leads to a higher initial order of the sediment and less texture exposure to changes.The fractal geometry values ​​of the grain fabric density of the fabric in different parts of Golestan province are not equal. Zones 3 and 1 have a higher order than zone 2. Zone 3, with the fractal number close to 2, has a high order during the deposition due to its proximity to the source. In zone 2, with a farther transfer, the particles have been highly subjected to changes in size and arrangement, and thereby the fractal number and order have been subjected to changes and decline. The highest fractal number is seen in zone 1. This can be due to the humid climate in zone 1, which induces the formation of secondary clay and increases the fractal numbers and sediment order. These results show that the content of clay can determine the order and homogeneity of the sediment texture. It can be concluded that fractal and its related parameters, as an efficient tool in analysis of loess sediment, can justify the zone of texture changes, distance from the main source, pedogenesis and climate and The results of DbH dimensions analysis in Golestan province's loess showed that the percentage of sand decreased, and the clay content increased with an increase in DbH. Comparing the fractal with textual sediment parameters indicated that the number of sorting increased and the particle sorting decreased with an increase in DbH, suggesting that the collected samples had a better PSD grading and a larger volume of particle size classes. Moreover, it was found that the kurtosis index decreased with an increase in DbH, and the curvature broadening increased with an increase in particle size classes.The results of Dbl fractal dimensions analysis in Golestan loess showed that the percentage of sand decreased, and the silt and clay contents increased with an increase in DbL. Furthermore, according to the results of laser sizing, the increased silt and clay contents led to a better sediments gradation. A negative trend of particle sorting against DbL means that the sorting index decreased and the particle sorting increased with an increase in DbL. on the other hand, a positive trend of kurtosis against DbL means that the kurtosis index increased and the curvature broadening decreased with an increase in DbL.Three stations, including AlmaGol, AlaGol, and Agh Ghala Belt in zone 3, had lower DbH and DbL, better sorting, and the largest median size, which could be due to the differences in the sediments' origins or the environment's form and retransfer, implying that the fractal values could help identify the transfer mechanism in different sediments.The fractal geometry would change with the changes made in loess texture. Therefore, a higher fractal dimension content indicates a higher soil formation and higher fine particle ratios. According to the study's results, should the particle distribution is well graded, it can be claimed that fractal geometry demonstrates the post-deposition changes in the loess. Based on the fractal results obtained from electron microscope images in Golestan loess, the grain's fractal dimensions increased with an increase in diameter, indicating that the grains are deposited with higher-order near the source, and the fractal number becomes smaller with the decrease in the grains' size away from the source. It was also found that from zone 3 (near the source) to zone 1 (away from the source), the grains' fractal dimensions decreased with an increase in particles roundness, implying that the sediments' order decreased and the texture underwent fewer changes with an increase in particles roundness. On the other hand, the grains' fractal dimensions increased with an increase in sphericity. Therefore, as the sphericity decreased from zone 3 to zone 1, the fractal number of grain dimensions decreased too, indicating that higher sphericity led to a higher initial order of the sediment and less texture exposure to changes.The fractal geometry values of the grain's fabric density in different parts of Golestan province are not equal. Therefore, zones 3 and 1 had a higher order than zone 2. Due to its proximity to the source, zone 3, with the fractal number close to 2, had a high order during the deposition. In zone 2, with a farther transfer, the particles were highly subjected to changes in size and arrangement, and thereby the fractal number and order were subjected to changes and decline. Moreover, zone 1 was found to have the highest fractal number because of its humid climate, inducing secondary clay formation and increasing the fractal numbers and sediment order.These results suggest that the content of clay can determine the order and homogeneity of the sediment's texture. Therefore, it can be concluded that as an efficient tool in analyzing loess sediment, fractal and its related parameters can justify the zone of texture changes, distance from the main source, pedogenesis, and climate, and determine the model of post-deposition changes.

The Sarvak and Ilam Formations in the Zagros sedimentary basin are known as hydrocarbon reservoir formations. More than half of the hydrocarbon fields in the Zagros Basin on the Sarvak and Ilam horizons contain hydrocarbons. In this research, to identify areas with hydrocarbon potential of the horizon of Sarvak and Ilam at Bandar Abbas hinterland, parameters such as outcrops of formations, main faults, salt plugs, isopach maps and upper sediment volume of formations from the geological map of the region and well data were extracted. With designing a network inference among data and using Fuzzy logic method with the high hydrocarbons, potential of the Sarvak and Ilam horizons were identified in the Bandar Abass hinterland. This area identified as a relatively weak area in terms of exploratory potential in Sarvak and Ilam reservoir horizons. 68% of the hinterland region has low hydrocarbon potential, 18% has medium hydrocarbon potential and only 14% has high hydrocarbon potential for exploration in Sarvak and Ilam horizons. However, considering the effect of anticlines, the mentioned percentages for areas with high hydrocarbon potential reduced to 4.3%. Together, it seems that the anticlines of South Gashu, Bastaneh, Kisn, West Namak and Suru have hydrocarbon potential in Sarvak and Ilam horizons.

The Alborz Mountains has been separated the subsiding Caspian Basin from the foreland basin of Central Iran. This mountain range from east to northwest, has changed greatly in structural trend formed spirally. Two orogenic phases, Cimmerian and Alpine events caused more changing in sedimentary basin of Palo Tethys and Neotethys and it caused the complexity of abundant structural in other way too. The aim of this research is to investigate and analysis of existence structures in east central Alborz from northwest of Damghan (South of Toyeh) to South of Sari (North Alborz fault). The Structural features Analysis indicate that the Alborz Mountains are a fold and thrust belt. During the intense shortening of Alborz crust in the studied area the initial model of folds have been modified or destroyed. Some of these folds could take place in flexural flow folds or Drug folds classes since one limb of folds on the surface of low-angel thrust faults was thrusted recumbently. The thrust faults with south and north dipping is the main controller for variety structures in this part of Alborz. Based on geological and structural properties, construction of folding structures initiated during the Alpine orogeny since the late Eocene (37 million years) and the most shortening and faulting had occurred during at the Late Miocene. Data presented here demonstrate that shortening percent in the study area of Alborz Mountains is about 36.27% and the Rate of Shortening is estimated about 0.93 mm/y.

In this study, the concentration-number fractal method was used for regional exploration studies, and determining the anomalies of copper, lead and zinc elements. For this purpose, 800 samples of stream sediments were selected from the rivers in the area (i.e. from Kahak and Aran geological maps, 1: 100,000 sheets) and then the anomalies of these elements were mapped. The results show that strong copper anomalies are observed in the northern, central, southern and western parts of the area and the highest lead anomalies are located in the western part of the area. Strong anomalies of the zinc element are located in the central, southern and western parts of the region. These anomalies coincide with the lithological units of andesitic- basalt lava, volcanic breccia, tuffs, dacites, small scale masses of quartz -diorite, and small-scale masses of quartz-monzonite. The obtained map from combining anomalies and faults map reveals that the anomalies are mostly concentrated in fault zones and fault intersection points in the area and faults play a fundamental role in ore mineralization.

The Studied area is located in the small part of the structural zone of Urumieh- Dokhtar Magmatic Arc, at 60km far from south of Qom and 12km far from south east of Kahak. In the beginning, 1:25000 map of the area was prepared, because, region is located in two 1:100000 scale map sheet of Kahak and Aran, and more rock units were separated. In the next step, in a several step of the field observations, 17 samples of regional volcanic rocks were taken for XRF and ICP chemical analysis, and they main Oxides, heavy metals and rare elements were identife. Most of the samples have been located in the Calk- alkaline series, and some in the Tulleit series. In the lithology diagrams, these samples respectively are arranged in the range of Andesite, Dacite, Trachy Andesite and Rhyolite Rocks. Due to the anomalies and the amount of Nb in the samples of the region, they formation can be related to the subduction zone. On the other hand, the depletion of Nb and Ti is special in magmatism in the subduction zone. Because in the subduction regions released fluids from floating lithospheric rich in LILE, increases in the mantle wedge. Since in the study area rocks exhibit calc- alkaline with moderate to high potassium, it can be concluded that the stones are related to active continental margin associated with subduction.

We used 2D seismic profiles, well data and field observation to describe the sub- surface structural styles and geological history of two basins in the northern part of Central Iran Basin (the Howz Soltan and Zavieh basins) from Late Oligocene to Pliocene. Two basin- bounding faults with normal- slip component, the South Moreh Kuh Fault (SMF) and the Howz Soltan Fault (HSF), controlled the thickness of Qom Formation and lower part of Upper Red Formation (URF) in the Howz Soltan basin, particularly during the Early Miocene to early- Middle Miocene. In the Moreh Kuh area, there is also a facies change within the Early Miocene succession from the hanging wall to the footwall of a south- dipping inverted normal fault, the North Moreh Kuh Fault (NMF). The change from carbonated deposits of the Qom Formation (in the hanging wall) to clastic dominated URF (in the foot wall) indicates that the NMF had been a normal fault which was subsequently subjected to inversion. In the Zavieh basin, the Oligocene- Early Miocene succession thins onto the basin margins. The lower part of this interval shows an onlap from the north towards the basin margin. This could be an indication that the basin wall had been slightly inclined prior to the marine transgression. Since the Middle Miocene and/or Late Miocene, the initiation of a regional compressional phase resulted in folding and reverse faulting in the Zavieh and Howz Soltan basins. The deposition of upper URF and Pliocene units was simultaneous with this stage.

The effect of basement’s upper surface morphology on the accommodation development is investigated in this study, through a case study from the Asmari Formation in Dezful Embayment and Abadan Plain. Considering the depth of the basement’s upper surface, position of the studying formation’s bounding surfaces, its thickness and total thickness of basin fill sediments are calculated. Based on the available data from previous researches and data extracted from more than 200 drilled oil wells in the studied area, the maps of basement surface, the Asmari Formation bounding surfaces, isopach maps of the Asmari Formation and total basin fill deposits are created. Results from this study shows the minimum and maximum depth of the basement’s upper surface 7,000 and 15,000 meters respectively. The deepest level of the surface is in the north Dezful Embayment, while the shallowest level in the southern Dezful and Abadan plain. The maps of the formations bounding surfaces well correlates with the basement’s upper surface map, especially in the north Dezful embayment area. Similar results are achived from the correlation of created isopach maps with that of basement’s top. However, slight discrepancy in the correlations is observed in the south Dezful embayment. Results of present study clearly show that development of accommodation space of the Asmari Formation in the north Dezful embayment and Abadan plain was mainly affected by the basement upper surface during different sedimentation periods. The accommodation space in the southern Dezful embayment was most likely affected from the basement faults’ actvities. Highest rate of sediment supply was recorded in the middle part of the north Dezful embayment.

Kuh-e-Ahan is a high-standing single relief within a rather flat plain, which is located in the north of the Tabas block, near the intersection of the Nayband and Kalmard faults and there are  great outcrops of  fe-oxide, along with eastern-western faults and fractures in Kooh-e-Ahan area.. The present study uses structural and remote sensing methods to discover the mechanism for evolution of the Kuh-e-Ahan, and to understand style of mineralization in the mountain, emphasizing on the role of fractures and major faults. In our remote sensing approach, we used DEM data and Aster satellite images and their filtering in main directions to detect displacements and sudden offsets of lithologic units and changes in drainage patterns. In our field studies, we studied mechanism of the faults, emphasizing on the faults within the Kuh-e-Ahan mining district. The results show N-S faults (Nayband fault trend) and NE-SW faults (Kalmard trend) have a general right-lateral mechanism, and the E-W faults are left-lateral with a reverse component. Structural model developed in this study suggest that strike-slip displacement on conjugate fault provided the space required for ascend and development of hydrothermal mineral deposits within the mine district.