The salinity of fresh water is one of the serious contamination threat of groundwater in many countries. GARU Spring in the East of Khuzestan province is one of the salty springs in the Zagros zone. Based on field investigations, possible sources of salinity in the region include dissolution of Gachsaran evaporative formation and oilfield brines. To identify the source of salinization in the study area, two sets of samples (20 and 17 samples) were taken from groundwater and surface water resources in February and September 2015 in order to determine respectively the main elements and Br. Combination diagrams of bicarbonate against calcium, magnesium, sodium, sulfate, and the ratio of Br/ Cl and TDI against chlorine were used as the best distinction between various origins of the salinity in the area. The results show that the main reason for salinity is influx of high volume of Temby river water in wet seasons and mixing with oil brines in dry seasons.

There are many springs in Iran contaminated by arsenic and therefore not suitable for drinking purposes. GARU spring around Masjed Soleyman city is an indicator of such springs. In order to study the concentration of arsenic, 20 samples were collected from the spring and Asmari anticline observation wells. Concentration of major and trace elements (i. e. As, Fe, Mn, Ni, V, and Li) in the samples were measured. ICP-OES studies were carried out on 3 samples of the surrounding formation. The results showed that GARU spring has arsenic levels higher than 10ppb. Hydrochemical and statistical analysis of water samples and sediment as well as significant correlation of arsenic with main cations (i. e. Nickel and Vanadium) showed that anthropogenic factors do not have an effect on the amount of arsenic. It is found, that the origin of arsenic is geogenic (Gachsaran formation and oil brine influx). The mechanism of arsenic mobility during wet season is the anaerobic respiration of Fe+3 reducing bacteria, whereas, in dry season, the environment is further reduced and as a result the activity of the SRB and IRB in the span of springs leads to the reduction of iron by sulfide from sulfate respiration, which causes arsenic deposition.

Despite the fact that kerogen decomposition has not been yet very well understood, it is possible to obtain kinetic parameters which correlate with both empirical and natural geologic data by pyrolysing samples in closed and open systems. In this study, in order to determine hydrocarbon source rocks kinetic parameters, synthetic maturation by using open pyrolysis system (Rock-Eval) was used. In order to determine the equation of the real pyrolysis temperatures, the Rock-Eval pyrolysis oven was calibrated against three standard samples. Three source rock samples from three well known Iranian source rock formations namely Pabdeh, GARU and Kazhdumi were anafyzed at temperature rates of 25, 15, 10 and 5°c/min and their kinetic parameters including activation energy distribution, Arrehnus coefficient and the amount of generated hydrocarbon were determined.

The Ghalajeh anticline with about 60 km length and NW-SE trend is located in Lurestan sub-zone and the Zagros fold and thrust belt. Geometry and kinematic of the folds of this zone are controlled by thrust faults and detachment levels. In this research, geometry and deformational style analysis of the Ghalajeh anticline and the role of the detachment levels on folding style have been investigated interpreting well data and construction of three cross-sections and calculation of geometric parameters. The structure of this anticline is affected by two detachment levels, which include the Pabdeh and GARU formations as the upper and middle detachment levels. Detachment levels and deep-seated and surface thrust faults in the southwestern limb affected the folding geometry and have caused the high thickness of the middle detachment level and inversion of the southern limb which waning southwestern part of the anticline, and the dip of the layers are normal which in turn caused fracturing. Analysis of geometrical parameter along the Ghalajeh anticline indicate that this anticline is an asymmetrical, cylindrical fold is an open half-angle round fold.

Source rock is one of main elements in petroelum system. In order to investigate a petroleum system in an oil region, it's necessary to recognize the characteristics of source rocks. In this study the source rocks of the Darkhovain oil field in Abadan plan are investigated. In this way, gamma rays and sonic log are used and source rock zones separated in Pabdeh, GARU, Gotnia, Najmeh, Sargelu and Nyriz formations. These zones sampled and total organic carbon of samples determined with Rock Eval analysis. Acording to Rock Eval results, Sargelu and GARU zones have good to excellent total organic carbon and good to moderate genetic potential. These zones have more thickness then the other zones. Kazdumi source rock samples show range of good to very good in total organic carbon and a range of moderate to good in genetic potential. Pabdeh, Sarvak and Surgah samples are poor in organic matter and have low genetic potential. Acording to this study, Sargrlu and GARU zones are main source rocks and Kazdumi and Nyriz zones are minor source rocks in Darkhovain field.

In this study, the geochemistry of heavy metals in the discharged waters of 16 brine springs, namely Pirmusa, dual springs of Gare-bardi, triple springs of Ghale-Madreseh, Batvand, Kuhzar, Aghili, Keh-e-Salen (Hafttanan), Ghasemabad, Ispareh, GARU, Dobalutan and Ramshir were evaluated. Most of the studied springs are discharged first in Karun river and finally to Persian Gulf. The assessments show that except for Ramshir and GARU spines cropping out in Mishan and Asmari Formations, respectively most of other brine springs are located in the evaporative Ghachsaran Formation. The maximum discharge ranges between 2 Lit/Sec (Ramshir and Ghale-Madreseh springs) and 330 Lit/Sec (GARU spring). The assessment of heavy metals dispersion and comparing with the standards of World Health Organization (WHO) and institute of standards and industrial research of Iran reveal that metals such as Hg, As and Pb are exceed than standards. Highlightly, Ramshir springs show variable degree of Cd enrichment. In the studied springs, the metal index is more than 1. Also, springs with close localities show the same variation range of metal index. Considering, the notable concentration of heavy metal in the studied brine springs and potential of undesirable environmental effects especially on quality and water resources ecosystem, attention and consideration of these springs seem to be necessary.

Darquain anticline is located at 5 km northeast of city of Abadan. The axis trend of this oilfield is north through south. In this study, Kazhdumi, Gadvan, GARU and Sargelu Formations in Darquain Oilfield, in Abadan Plain, were analyzed by Rock-Eval 6 instrument. S2 vs. TOC plot revealed that kerogen type in this oilfield predominantly is of mixed of types II & III. Significant S2 Adsorption by matrix of Kazhdumi Formation in well numbers 1 and 2 (5.33-14.06 mg HC/gr rock) and Gadvan Formation in well numbers 2 and 3 (3.1-3.2 mg HC/gr rock) is due to low thermal maturity as well as low Gas-Oil Ratio factor. In GARU and Sargelu Formations amounts of adsorbed S2 by matrix are respectedly 0.82 and 0.84 mg HC/gr rock, that represent a medium thermal maturation and medium to high Gas-Oil Ratio factor. Quantity of TOClive in the Kazhdumi, Gadvan, GARU and Sargelu formations estimated to be in the range of 0.6-1.6, 0.2-1.9, 1.53 and 8.38 by weight percent respectively. This represents potential for the studied formations fair to excellent petroleum generation. Also the studied wells were modeled, by which the Ro of the source rocks were calculated according to their depth. Also transformation ratio of organic matter and the initial TOC is estimated. Transformation Ratio of Kerogen in studied formations ranges from 0.12 to 0.66. This is in accordance with estimated Easy Ro by PBM software (0.5-0.8). It can then be concluded that Kazhdumi Formation is in early oil window and already started to generate hydrocarbon. This is also verified by Tmax data. The Gas-Oil Ratio of Kazhdumi and Gadvan Formations is 0-1 indicating variable hydrocarbon generation. Also this factor for GARU and Sargelu is 0.58-1 indicates that they have more gas generation potential rather than oil generation potential. The inferences drawn from It can be inferenced from iso TOCoil and TOCgas maps led to the conclution that, in west and southwestern parts of the basin, the depth during deposition of mentioned formations was more in compare to other parts of Darquain.

Structural analysis of folds across the western part of the Lorestan zone in Zagros fold-thrust belt showed that geometry of the folds are varies in different structural levels and leads to change in the folds style to depth. Competency contrast of rock units is the main controlling parameter of such a diver's behavior. Rock units with lower competency, as detachment surfaces, play a significant role in deformation style and its diversity down to depth. The Pabdeh, Gurpi and Illam Formation which are overlaying on incompetent GARU Formation compose outcrops of the study area.It is interpreted that the GARU and Pabdeh Formations are the major detachment zones control fold style across the study area. Geometric test of the folds constrain the effect of the detachment zones on variation of deformation style between their upper and lower rock units. In such a manner that folds in lower units to these detachments have larger wavelength comparing to ones developed within the overlying units. Similarly, strain partitioning within the whole sequence between competent and incompetent rock units demonstrate that change in geometry and folding style from surface to depth, in Lorestan zone, is mainly affected by diversity in mechanical behavior of rock units or in other words the effect of mechanical stratigraphy.

Babahabib and Sarkan oilfields are located in southwest of the Lurestan Province and 10km west of Pul-dokhtar City. The study area is situated in the Lurestan tectonostratigraphic region, northwest of the folded Zagros structural sub-zone. Although the Lurestan region is part of the Zagros sedimentary basin, it shows essential differences in terms of sedimentary conditions and types, folding and thickness of strata sequences when compared with the Dezful and Fars basins. Information obtained from seismic profiles, well logs and four cross-sections (AA´ to DD´) drawn perpendicular to structural trend indicates the effect of the detachment surfaces on structural geometry of folds in study area. Of the most important dataset used in this study are 2D and 3D seismic lines along with well logs, which were used in geometrical analysis of subsurface structures. According to surface and subsurface structural geometries of fold in central part of the Lurestan region, two detachment surfaces including (1) GARU Formation as the middle detachment surface and (2) Amiran Formation as the upper detachment surface are interpreted to have affected subsurface anticlines (Bangestan group) and small surficial anticlines, respectively. The thickening of the upper detachment surface in western part of the study area has resulted in the development of folds with short wavelength and amplitude in outcrops. This thickness change causes disharmonic folding in surficial anticlines relative to the subsurface anticlines. The geometry of the Sarkan and Baba-Habib anticlines is represented as asymmetric detachment fold in which the increased stress in middle parts of the anticlines plus backthrust structures have developed a geometry resembling Mitras’s (2002) model-1 faulted detachment fold. This model is formed by the high competency contrast between the GARU shaly units at the base and the overlying competent formations of the Bangestan group. Relay geometry of thrusts, which have been initiated from incompetent lower units, is one of the most important factors in controlling the en-echelon arrays of sub-surface anticlines in the area. Surficial geometries of the anticlines have been controlled by the upper detachment surface.

In the southwest of Iran there are large reservoirs of oil and gas including Jurassic and Cretaceous carbonates, in which they are suitable source rocks in the succession of the Early Cretaceous and Jurassic. The purpose of this Research was to evaluate the maturity of hydrocarbon fluids and to determine the migration path and properties of Pabdeh, Kazhdumi, GARU and Sargelu source rocks in the study area. For this purpose, one-dimensional burial history and thermal modeling in four oilfields and two-dimensional modeling for the study area were performed using Open Flow software to determine the maturity levels of the sedimentary, calving, and kerogen layers (s). Hydrocarbon outflow was evaluated. Comparison of measured vitrinite temperature and reflectance values with model results was used for model calibration. The results of one-dimensional modeling of the burial and thermal history in this study show that the kerogen (s) of the Sargelu, GARU, and Scorpion Formations have matured and have hydrocarbon outflow, but the organic matter or kerogen (s) of the Pabdeh Formation Not enough maturity to produce hydrocarbons. The results of migration model in the studied section show that the two Early Cretaceous and Middle Cretaceous hydrocarbon systems were separated by Kazhdumi Formation and therefore hydrocarbon migration in deeper layers of Kazhdumi was mostly lateral to Abadan plain. The hydrocarbon produced from the Kazhdumi Formation, in addition to charging the upper layers, migrated laterally to the Abadan plain due to the overall slope of the Ilam and Sarvak layers. In general, the maturation process of the source rocks decreased from east to west of the study area.