[en] A thick clastic sequence is well-developed in Tang-e-Zakeen, Kuh-e-Faraghan, being situated approximately 80 Km north of Bandar Abbas. The sequence is 340 m. thick and mainly consists of sandstone, siltstone, shale and subordinate dolomitic beds. So far, this clastic sequence has been called Faraghan Formation. This rock unit lacks marine fauna and based on stratigraphic position, it was assigned to the Early Permian (Szabo and Kheradpir, 1978). Since then, a detailed palynological study has been carried out on the Faraghan Formation by the author. These studies resulted identification of numerous palynomorph taxa, including miospore and acritarch species. The known palynomorph taxa indicated that, a major part of Faraghan Formation belongs to the Devonian Period, while the rest is Early Permian. As a result, the National Iranian Stratigraphic Committee decided and agreed upon to divide the Faraghan Formation into two rock units, namely, the Zakeen Formation, embracing the Devonian strata, and Faraghan Formation for the Early Permian sequence in the Zagros Basin respectively. The Zakeen Formation derives from the Zakeen Village which is located in the southern flank of Kuh-e-Faraghan, about 80 km north of Bandar Abbas. The type section of Zakeen Formation attains a thickness of 285m. in Tang-e-Zakeen, Kuh-e-Faraghan, approximately 23 Km from the Zakeen village. It disconformably rests on the Sarchahan Formation, while it too, disconformably overlain by the Faraghan Formation. A total of 100 samples from the Zakeen Formation were selected and treated in the palynological laboratory of the Exploration Division of National Iranian Oil Company. 63 palynomorph taxa were encountered from the Zakeen Formation. The known species were arranged in five local stratigraphic assemblage zones. Zones I and II occur in a thickness of 96 m. of the Zakeen Formation, in ascending order, suggesting the Early Devonian whereas Zones III and IV occur Within 156 m. interval of the Zakeen Formation, representing the Middle Devonian. Lastly, the zone V is represent by 35.5 m. of rock-interval indicating the Frasnian age. The Zakeen Formation is not similar to any Devonian rock unit in the Alborz Ranges, as well as the Central Iranian Basin, but it is similar and equivalent to the Devonian rock units (Tail, jauf and Jubah formations) of the Saudi Arabia and southern Persian Gulf regions

[en] East Iranian structural Belt, one of pre-Cenomanian age. Stratigraphical and lithological evidence indicating the beginning of tensional movements between Iranian and Afghan microcontinents in Early Cretaceous. Thus, creating the sedimentary basins of East Iran and this in turn led to the appearance of the ophiolitie sequence in the area. The alleged ocean, created in this area, was closed during the Late Cretaceous and furthermore, the foreland basins were dominant features throughout the Cenozoic times. Regarding the structural evolution of the area, varying hypotheses have been propounded. But, considering the structural characteristics of the area as. compared to the other parts of the Lut Block, the structural model of the Ghalehsorrh-Nowzad Fault is more feasible solution for the emplacement of the metamorphics as well as the ophiolitic sequences. The latter fault itself is one of the branches of the Neh Main Fault. However, that Segment of Ghalehsorkh-Nawzad Fault in the east of the area of Sarbisheh, 1:100,000 Map is a strike-slip fault with a dextral displacement in its first order class, whereas, occasionally sinistral in its secondary-third orders. the structural evolution of this fault occurred in the Riedel system with positive/negative flower structures in its compressional and tensional parts. The stress mainly concentrating in the junction of different segments and in their tip points. The release of these stresses are likely the cause of the recent earthquakes

[en] Zarin Playa is located about 75 km northeast of Ardakan in central Iran and covers an area of about 600 km². Based on textural, mineralogical and geochemical characteristics, of sediments, Zarin Playa have been divided into the following zones, starting from margin towards the center: high sandy mud, low sandy mud. salt zone and wet zones. One of the most important geo morphological features in the study area is the sand dunes that extends from southeast toward northwest and divides playa into two parts. Geochemically, the most common oxides in surface sediments of playa is SiO₂ and the most common is quartz which is related to the exposure of high content quartz rocks around the playa. The maximum concentration of evaporites minerals are at the depth of 200 cm, which is the surface of water table, and also at the depth of 40 to 50 cm below the surface which is related to the evaporation of high saline sub-surface water. Hydrochemistry of groundwater shows that the most common cations and anions in groundwater, are Na, Ca, Mg, K, Cl, SO₄, SO₄^-2, CO₃^-2 + HCO₃^- Hardness and total dissolved solid of groundwater are very high and Ph is in the range of neutral to slightly alkaline water. Based on chemical composition, the groundwater can be classified as a second type of meteoric saline water. In general, geochemistry of sediments and hydrochemistry of sub-surface water in Zarin Playa are mainly affected by the lithology of the surrounding rocks

[en] Iran magnesite deposits are mainly discovered in eastern city of Birjand. Afzalabad, Torshak Mohammadi, and Chah Khoo. Magnesite deposits were studied with respect to major, trace elements and C-O isotopes. Magnesite are found mainly within ophiolite. They form as vein and lenses. Magnesite mineralization is associated mainly with Nehbandan and Neh fault systems. Nehbandan fault is very steep and also is very deep. North Afzalabad Magnesite has the highest Na-content (259-1670 ppm) and this is the result of fly sch found in the foot wall. South Afzalabad has the lowest Na- content (12 to 275 ppm) because there in no fly sch type rocks in the area. Huntite has the highest Na - content ranging from 3046 to 3468 ppm. The lowest Sr found in South Afzalabad (2-8 ppm) and Chah khoo (0-50 ppm). The highest Sr content (35-211 ppm) found is Turshak Mohammadi and North - Afzalabad deposits. The highest Mn and Fe found at Chah khoo and North Afzalabad deposits and the lowest Mn and Fe is associated within Torshak mohammadi and south Afzalabad deposits. Huntite has the highest Mn and Fe content. C-O isotopic composition of magnesite from Torshak Mohammadi, Afzalabad and Chah khoo were compared with magnesits deposits associated within Alpine ophiolite belt discovered in Turkey, Greece, Yugoslavia, Austria, and California. The C-O isotopic composition of alpine ophiolite are δ¹⁸O_(SMOW)=23-27%, and δ¹³C_(PDB)=-17 to -6 %δ and all of them plot in the same region, but Afzalabad, Torshak Mohammadi and Chah Khoo plot in different field. The δ¹⁸0% values of magnesite deposits in Eastern iran ranging from 31-36 (% SMOW) and δ¹³ C ranging is between 1.8 - 8 (% PDB). The CO₂ had atmospheric origin and the H₂O have meteoric origion

[en] Mash had granites and Gran diorites are divided into three groups bas sed on their ages and composition: (1) Deh Now-Vakilabad-Kuhsangi Granodiorites and Quartz monzodiorites, (2) Sang bast Granite and (3) Khalaj- Gheshlagh Biotite-muscovite Granite. All these intrusive s belong to S-type granite, The oldest are in the range of intermediate and the youngest are acidic in composition. Intrusive rocks in the area of Deh now to Kuhsangi show trend of differentiation. Major, trace and rare earth elements within the source rocks of porphyry Sn, Mo, and Cu deposits were compared and very distinct differences were noticed. Differentiation index, Rb/Sr, Ce/Yb, and (Sr⁸⁷/Sr⁸⁶) ratios can be used to identify the source rocks for porphyry Sn, Mo, or Cu. Major, as well as trace and rare earth elements of Mash had Granites and Granodiorites were compared with tin mineralized granites of the world. As a result, four diagrams were presented to be utilized in order to discriminate between Sn mineralized and non-mineralized granites. Such as Rb to the ratio of Sm/Eu, F to Rb and the three angle of F, Rb, Sr + Ba

[en] Explosion-generated seismic signals have been of interest for many years, especially in connection with geophysical studies for scientific and industrial purposes. Increasing the yield of an explosion in a given type of rock does not necessarily mean a proportional increase in the seismic-signal amplitude. The geological environment in which a nuclear explosive is emplaced has a major influence on the strength of seismic signals. Estimating the yield of underground nuclear explosions from far-field seismic waves is a difficult problem, since accurate estimates require a detailed accounting for source-region and travel-path differences between known and unknown yield events. For short-period P-waves, the first problem is to obtain an unbiased measure of the far-field energy. Conventional m_b seems unsatisfactory because of the large scatter in station values. The dominant cause seems to be wave focusing/defocusing by complex earth structure. For yield estimation, it is important to characterized each event by an unbiased measure of the P-wave energy leaving the source region. It is clearly very difficult, and perhaps impossible, to substantially reduce the scatter in conventional m-b data. The suggestion with the best theoretical support is to use the ^b phase^, since it is least contaminated by p^p and other later arriving energy. The data used in this study were taken from 25 semipalatinsk test site explosions recorded by SRO located at Mashhad. Reasons for selecting 25 records from 50 total records was based on signal to noise ratio and availability of announce yields. For each event the amplitude of short-period vertical component of the records were read. Also magnification was removed from all records. With attention to epicentral distance (about 19 degrees) the first arrival is the direct P-wave passed through the mantle. Since with one station we cannot remove focus/defocus effect, it is better to use the amplitude instead of the magnitude in order to estimate the yield. However, the yield-magnitude relationship was calculated. We could obtain better results when using ^b phase^rather than the other phases. It is concluded that ^b phaseⁱs a good tool for decreasing scattering of the data. The derived relationship is: log(A) = 0.807 log(Y) + 1.049, R² = 0.8014. So, this formula is recommended for calculating the yield of Semipalatinsk explosions recorded in SRO station, at Mashhad

[en] In this research, two stratigraphic sections were chosen from the late Paleocene to early Miocene (Jahrum and Asmari Formations). These sections includes Sadra and Dodaj plus 645 meters of late Paleocene to early Miocene sediments. For this investigation 360 thin sections were prepared and 12 samples analysed by X RF. We studied Bio tope that includes biozone. These index biozones and percentage of elements that appears in bio tope are identified. Principally index foraminifers, identified in the studied sections, are listed bellow: Miscellanea sp. Kathina sp., Fallotella alavensis Mangin, Opertorbitionlites sp. Alveolina sp. Lituonella ruberti Stache, Rhapydionina urensis Sirel, Orbitolites complanatus Lamark, somalina Stefaninii Silvestri, Dictyoconus sp. Coskinolina liburnica Atache., Nummulites fabianii Prever, Silvestriella tetraedra Gumbel., Nummulites fichteli Michelotti, Austrotrillina howchini Schlumberger, Meandropsina anahensis Henson. Regarding the frequency, type of wall and biotope percentage ratio of each foraminiferal biozone, there are different biotopes that indicate change in the trend of paleoecologic conditions of the late Paleocene to Oligocene sediments

[en] Petrofabric, structural and geochemical study of the ultramafic tectonites in the Khoy ophiolitic complex suggest that these tectonites including low-temperature North West-South East shear zones cut the high-temperature to medium-temperature North East-South West mantle flow direction. Microstructures in these tectonites, record a fabric transition from oblate porphyroclastic and oblong porphyroclastic textures (related to the high- and medium-T deformations in mantle sections) to mylonitic textures (with low-T deformation in the shear zones). The study of olivine LPO patterns in high- and medium-T deformation samples of mantle shows slip on the (010) [100] high-temperature-low stress and (0 kl) [100] moderate-temperature systems (up to 1000^deg⁾ while olivine LPO patterns in the low-T deformation samples within the shear zones indicate gliding along (001) [100] low-temperature slip system (800-900^deg⁾. Spinels in these peridotites show high variations in Cr number (10 to 90) and Mg number (50 to 90). Cpxs rich in Cr suggest a low degree of partial melting in these peridotites. The very variable composition of the spinels may be the result of partial melting process and recrystallization of these minerals in the mantle lithosphere during the detachment phase and the development of the shear zones

[en] The Kopet-Dagh Basin is located in the north and northeast of Iran. From Jurassic through Miocene, the sedimentation went on relatively uninterruptedly in this basin. The area of study is located in the Cheshmeh Gilass Mountains which is situated about 50 km northwest of Mashhad. the purpose of this study is to identify different lithofacies, as well as, ultimately to interpret the depositional history of the Shurijeh Formation in this area. The Shurijeh Formation (Nicamin; Kaltron, 1969), is about 490 meters thick in this area, and conformably overlies the Modernize Formation (Upper Jurassic) and conformably underlies the Tanager Formation (Apt ian). This internal is mainly composed of re dbed siliciclastic sediments and mostly fine to medium-grained rocks (shales and sandstones), that have been deposited in fluvial environments. Carbonates (mi critic limestone and dolomite) and evaporate (gypsum) lithofacies of this formation indicates that, they were deposited in a closed basin (probably lake) under arid to semi-arid climatic conditions

[en] Aqdarreh intrusi body with an area of 30 km ² is located in 34 km north of Takab, northwest of Iran. This batholith is situated in Central Iran, cutting Paleozoic rocks. Radiometric age of Aqdarreh batholith by K-Ar method is 48.38 m. a.,corresponding to Eocene magmatism. Aqdarreh intrusive body consists of tonalite, granodiorite, alkali feldspar granite and monzogranite in which the main mafic mineral is biotite. Further more, there is not any enclave in these rocks. Study of the investigated samples shows that Aqdarreh intrusive rocks have two different generations. Part of the collected samples belongs to I-type granite (calc-alkaline) and others represent the A-type granite (alkaline). It seems that this process is created by the contamination of alkaline magma by crustal materials. Geochemistry of the rare earth elements shows that the tectonic setting of the body is compatible with Post Orogenic Granitoids