In the present work 35 cutting samples from 5 oilwells of Masjede-Soleiman oilfield have been pyrolysed by Rock-Eval6. Results indicate that, Kazhdumi, Garu and Sargelo formations have high TOC and Tmax values, passed diagenesis stage and therefore, have high hydrocarbon generation potential. Van Krevelen diagram demonstrating the studied formations shows type III kerogen for Sargelo formation and mixed type III/II kerogen for rest of the formations. Sargelo formation with Tmax up to 481°C not only crossed the oil window but also has reached wet gas generating stage. Total Organic Carbon and Tmax increase from northwest to southeast and also prove the increase in hydrocarbon genetic potential of Masjede-Soleiman oilfield.

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.

1D modeling of oil generation is one of the methods used in petroleum system investigations. The candidate source rocks in the Pazanan field were subjected to 1D thermal modeling in order to investigate their maturation history and hydrocarbon generation. Oil generation modeling of the Pabdeh, Kazhdumi, Garau and Sargelu source rocks were constructed, in the Pazanan anticline and also in southern and northern synclines. Based on the investigation done during this study, it is evident, that there are significant differences between oil generations in the drilled wells in comparison to the adjacent synclines. These differences indicate that for example the Pabdeh Formation in Pazanan anticline is not reached to oil generation, while it is in peak of oil generation in northern syncline.The obtained oil generation history of source rocks during this study showed that quantity of oil generated of the Pabdeh and Kazdumi source rocks in synclines are more than anticline. In addition the oil generated from Garau and Sargelu formations is more than that of Pabdeh and Kazdumi source rocks.

The Ahwaz oilfield is located in the Dezful embayment of the Zagros fold-thrust belt in SW Iran. The oil source rocks predominantly with the argillaceous lithologies include the Kazhdumi, Gurpi, and Pabdeh formations as well as the basal part of the Asmari Formation. The concentrations of the major, trace, and rare earth elements (REEs) of these lithologies were determined using x-ray fluorescence spectroscopy (XRF) and inductively coupled plasma-emission/mass spectrometer (ICP-ES/MS), in order to infer the geochemical characteristics of the oil source rocks. The North American Shale Composite (NASC)-normalized major oxides displayed a positive anomaly in CaO, negative anomalies in other oxides and no anomaly in P2O5. According to the spider diagram of normalized trace element, there was enrichment in V, Ni, Cu, Cd, Pb, and Th values. In the NASC-normalized REEs pattern, the oil source rocks mostly display a smooth distribution shape, negative cerium anomaly, and slightly positive anomaly in the middle rare earth elements (MREEs: Sm-Ho) values. The concentration of V, Ni, Co, and their ratios suggested a mixed marine and terrigenous source input. The ratios of redoxsensitive elements such as Ni/Co, V/Ni, V/V+Ni, Th/U, and Ce/Ce* suggested that the oil source rocks were mainly deposited under anoxic condition.

Surface oil seeps from Alasht, Lapur and Jenesem share many compositional affinities including distributions and concentrations of normal alkanes, terpanes and steranes. These oils also show many similarities with that of Jurassic sediments (Shemshak Group, Klariz Formation) systematically sampled from the Galandrud Coal Mine. Recent geochemical studies in this area indicated that the Shemshak Group is rich in organic matter and has potential to generate oil and chiefly gas. The Kalariz Formation here is composed of 350 m of mudstones, siltstones and fine-grained sandstones with over 30 coal seams. This formation is thought to have sourced Alasht and Lapur oil seeps. GC and GC-MS chromatograms of Jenesem oil are unique and show no any similarities with that of above mentioned oils or the Shemshak Formation. This indicates that the Jenesem oil has been generated from a different source rock but its origin is still unknown.

In this study twenty seven shale and marl cutting samples, which where source rock candidates in the Binakoil field were pyrolyzed using Rock-Eval-6 instrument. Results indicate lower hydrocarbon potential for Pabdeh and Gurpi formations while, Kazhdumi and Laffan show much better potential and act as main source rocks. Kerogen type 11 and mixed type II/III which are oil and oil/gas precursor, are prominent. Organic matter depositional environment was determined by hydrogen index vs.oxygenindex, and reducing with minor oxidation environments exhibited. Thermal maturity index (Tmax) of organic matter shows that all the samples entered oil window while none crossed it to metageneticst age. Hydrocarbon potential (S2) to total organic carbon (TOC) indicate negligible role of mineral matrix to the pyrolysis process. Trend of Toe increase is from north to north east of the oil field to south and south west and this exhibits the higher hydrocarbon potential in the same trend. It is therefore suggested to .consider this trend in future exploration drilling so as to reduce the 4rilling risks and increase forecasting efficiency significantly.

Genetic potential of four probable source rocks in Marun oilfield; Pabdeh, Gurpi, Kazhdumi and Garau were investigated. It shows that only pabdeh and particularly Kazhdumi Formations have potent ial to generate hydrocarbons. The Hydrogen Index (HI) vs. Total Organic Carbon (TOC) in four formations indicates direct relation between the two parameters. Kazhdumi Formation with high Hydrogen Index comprises higher amount of total organic carbon. This could be due to reducing environment of organic matter depositional conditions. Maximum Temperature (Tmax) and depth variations shown by diagram in well No. 123 and 222 of Bangestan reservoir in Marun Oilfield indicate that inbothwells Sarvak shales are just at the beginning of oil window, but in well No. 222 Tmax variation versus depth is more severe and Tmax is higher in Kazhdumi Formations. Plot of S2 vs. TOC for inert carbon determination indicates 0.5% in Pabdeh and Gurpi, whereas inert carbons in Kazhdumi are not more than 0.25%. Organic facies curves for Kazhdumi and Garau places them in B to BC zones showing marine reducing with minor oxidizing environment. In Pabdeh and Gurpi, organic facies is variable and consist of a mixture of marine and terrestrial organic matter, indicating transgression and regression of the sea. The van Krevelen diagram indicates kerogen type II/III for all formations, but only Kazhdumi Formation is in the cat agenesis and oil window territory. Finally, among the four studied formations, Kazhdumi with highest organic carbon and optimum thermal maturation is introduced as the best source rock for Marun Oilfield.

In southeast Tabriz, as a part of Western Albourz-Azarbaijan magmatic belt the vocanic and pyroclastic rocks of Sahand cover vast areas. The volcanic rocks include andesite, dacite, rhyodacite and rhyolite and pyroclastic rocks largely occur as vast ignimbritic outcrops. Based on high LILE/HFSE and LREE/HREE ratios and their similar composition to subduction volcanic rock suites; it seems that they have formed in a subduction zone. The subduction process had low effect on the concentration of Zr, Ta, Hf, Sm, Tb, Nd, Eu and Y, while it had strong influence on concentration of Th, U and La. Concentration of elements such as Ba, K, Rb, Cs, Sr, Pb shows that these rocks belong to calc-alkaline series. The studied rocks show considerable similarity with calc-alkaline rocks from Turkey and from this point of view; these rocks belong to post-collisional arcs. In this tectonic setting, magma ascent is controlled by strik-slip faulting and associated pull-apart extensional tectonics. This post-collisional magmatism may have occurred due to Arabian-Iranian plate's collision.