Background and objectives: To reveal plants systematic and phylogenetic evolutionary development of the species, wood identification and wood anatomical descriptions were being considered by Biology researchers every so often. From Palaeobotany point of view, there have been done successful researches by studying wood fossils. Petrified woods preserve more extended history of wood habitats comparing to other plant organs. In this study, we identify and introduce fossil woods of Annakhatoon NE of Tabriz region, which were explored from 1: 25000 map preparation operations.Materials and methods: In this study, we put to use stem like pieces to make identifications of the petrified tree stems of the age Pliocene, NE Tabriz. Appearance, size, color and other physical characteristics were recorded and photographs prepared, after transferring the collected samples to the laboratory. We prepared thin sections of all types of transversal, radial and tangential planes, according to specific methods, whereas possible. First of all, we cut 1*2*3 cm pieces with their long axis parallel to the tree longitudinal axis, removed rough areas, planed and finished. After making a polish, the thickness was so lowered around 0.03 mm that the light could pass through the wood thin sections. Thin sections of tangential, radial and cross section were prepared to study microscopically. In the cases where the state of preserving allowed, we studied wood anatomy and the features related to tracheids, ray parenchyma, pits, resin canals and other wood elements employing light microscope. Following IAWA list of microscopic features of Gymnosperms, made the elementary descriptions the identification was completed by comparing data with other petrified woods in collections elsewhere.Results: The results showed that the structure of fossil sample was the same as Gymnosperms.Growth ring boundaries distinct, transition from early wood to latewood abrupt, ground tissue consists of thin walled tracheids, uniseriate rays abundant, unlikely pinoid bordered pits in cross fields and a few solitary resin canals, were common. The material has been referred to Pinuxylon fossil species of Coniferals at this stage.Conclusion: Although lack of proper preservation, solitary resin canals, few axial parenchyma, large bordered pits arranged in single rows at radial walls of early wood tracheids and very likely pinoid pits in the cross fields, show close relation to Pinuxylon genus type. This genus type implies a temperate climate there at that age.

Kuhbanan fault system, as one of the intercontinental faults of central Iran, is recognized by considerable seismogenic activities and modem morphotectonics evidences with a strike-slip (reverse component) motion. According to the geometric and kinematics data, Kuhbanan fault has been divided into 5 segments (S26, S27, S28, S29, S30) in Bahabad region. Measured geomorphic indices of ratio of valley-floor width to valley height (Vf) and morphology of the valley (V) manifest the maximum denudation rate for the S28segment. The mean calculated values of mountain-front sinuosity (Smf) and %facet parameters for different segments of the fault are 1.1 and 83.16, consequently. Regarding to these geomorphic indices, a denudation rate of about 2-4 mmyr-1 is suggested for this region.According to reconstruction of Kuhbanan fault since 360 ka, minimum horizontal cumulative displacement of 750 m and minimum slip rate of about 2-1.4±0.1mmyr-1 is inferred from well preserved geomorphology in the northern segment of the fault. Applying this horizontal cumulative displacement causes reconstruction of geomorphic markers such as drainages and shuttered ridges.

The Pliocene calc-alkaline volcanic rocks are exposed in two areas in southeast and northwest of Isfahan and consist of andesites and dacites. Based on geochemical data and multielements pattern, these rocks are medium to high calc-alkaline suite and they show LILE and LREE enriched normalized multi-element patterns, and negative Nb and Ti. Condritenormalized REE patterns display a steep decrease from LREE to HREE without any Eu anomaly. They have higher SiO2 and Sr content and Sr/Y and La/Yb ratios and low MgO, Mg#, Y and Yb contents than the normal calc-alkaline volcanic rocks. These volcanic rocks show adakite characteristics. These features are consistent with ratios obtained from orogenic related volcanic rocks. These rocks may have been produced by partial melting of thickened lower continental crust or slab probably transformed to eclogite or garnet -amphibolite. HREE and Y depleted pattern suggest the existence of garnet and amphibole as a residue in the source.

Chelken Formation (Lower and Middle Pliocene) which represents a siliciclastic nature in Javarom Section (south of the Ghaemshahr city) was studied. This formation comprises three sets of conglomerate, sandstone and mudstone, which are usually arranged in fining upward sequences. According to the nature of fining upward sedimentary sequences, sedimentological characteristics and structural features, it is proposed that the Chelken Formation was deposited in a fluvial environment. Conglomeratic facies are mainly clast-supported, sandstone facies are represented by quartz arenite and lithic arenites and mudstone facies are carbonate-clastic in nature. According to the paleo-currents analyses, a north and northeastward direction is proposed for the paleocurrents deposition of this formation.

The Cenozoic volcanic activity of the Harrat Ash Sham volcanic field in south of Syria is a part of the extensive magmatism that took place in the auxiliary extension faults along the Dead Sea Fault Zone from upper Eocene to Holocene. Pliocene volcanic rocks form an important part of igneous succession in Syrian Part of Harrat as Sham. These rocks vary from basalts flows to scoria. Pliocene basalts are divided into three primary petrographic groups: olivine basalt, olivine-pyroxene basalt and basanite. The three petro-types are alkaline and have similar compositional ranges of major and trace elements. Variations in the contents of major and minor elements in the Pliocene basaltic rocks are very slight. Such homogeneity in the chemical composition indicates to the operation of petrological processes that reinforced each other during the genesis of these rocks. The geochemical characteristics of the Pliocene basalt rocks reflect crystallization from primitive basic magmas that have experienced limited crystal fractionation process subsequent to their derivation by partial melting of the upper mantle.

Fourteen seismic-reflection profiles of northeast Ramsar, SW Caspian Sea, were investigated to define seismic fades, depositional processes and potential stratigraphic traps below the Upper-Pliocene time-line reflector. Four seismic fades were defined: I) parallel layered fades, 2) chaotic fades, 3) mounded fades, and 4) protruding fades. The parallel-layered fades is the most dominant, its continuity increases basin ward. The chaotic facies mainly occur as shale diapires which were intruded into the overlying sediments. The deep-water deposits are the mounded and prograding fades which are related to deltaic processes and occur north of the study area. Various internal reflection patterns of the mounded fades indicate different processes were active during their formation. Potentia l stratigraphic trapsmay be found in sediment mounds, buried channels, prograding clinoforms and debris-flow lobes, among which sediment mounds are more significant. The largest mound is 18.8 km wide and 480 m high.

The Dorud-Khorramabad Railway, with a length of 114 km, is under construction in 5 separate phases. In terms of geology, a large part of the route passes along the High Zagros and the Chaghalvandi Thrust in the form of tunnels and other structures. Phase 5, which is 26 kilometers long, from the 72nd kilometer to the 98th kilometer, between the Biran-Shahr Plain and the Deh-Pir region in North Khorramabad City, has two tunnels with a length of more than 7, 500 meters. Given the local climate and the ground water level (average depth of 10 meters) on this route, for the sealing of the tunnels, it is necessary to study the rock mass. For this purpose, it is necessary to understand the characteristics of Pliocene Conglomerate including the mechanical and the physical parameters of the tunnel. The present study tries to determine the permeability by means of the data of water pressure tests. The groutability in this rock unit, in turn, was determined based on the Secondary Permeability Index (SPI). The results show that the behavior of this rock mass is 19% in Class C, 67% in Class B, and 14% in Class A in terms of the SPI, and that 86% of the rock mass needs to improve by means of cement grouting operations. Totally, because of similar geological conditions in the railway route, all of the railway route needs to improve.

We used 2D seismic profiles, field observation and well data to constrain the structural evolution of the Saveh basin during the late-lower Miocene to late Pliocene. During this period almost 8-9 kilometers of Upper Red Formation (URF) and the Pliocene conglomerates were deposited in the depocenter of the basin. During the late-lower Miocene (to early-middle Miocene? ), Syn-depositional activity of west-east-northwest-southeast trending high-angle fault zones, with an extensional component, created accommodation space for deposition of lower URF. Since the late-middle Miocene (or late Miocene), initiation of a compressional phase has resulted in regional deformation. The deposition of upper part of the URF and the Pliocene unit was contemporaneous with compressional deformation. During this stage, the middle part of the URF acted as an effective detachment horizon and detachment folds such as the Saveh and Taraz Naeen anticlines were formed. The thinning of the Pliocene conglomerates towards the crestal point of these folds indicates late structural growth. According to the top Qom depth map, there are no traps with fault independent closure within the Saveh basin. The top of the Qom Formation is estimated at-4250 m in the Taraz Naeen anticline.

Flat lying Pliocene-Quaternary detritic sediments with various thickness and color were cut by normal faults in restricted area in the Zanjan depression, 45 km northwest of Zanjan city. Along the road cuts, including the Zanjan-Tabriz free-way, young flat-lying Pliocene-Quaternary sediments were cut and displaced by abundant normal faults that exposed locally in 90 square kilometers. These normal faults are approximately E-W in strike and have pure dip-slip movements. Horst and graben structures are abundant in the study area due to conjugate faulting. Along the fault zones, structures like: change of dip due to layers lithology and reology, fibers growth of gypsum, striations and grooves on the fault planes are developed. Striations on the fault planes are parallel to the main dip of the fault planes implying displacement due to gravity. Development of normal faults in restricted area in Zanjan depression produced as a local pull-apart basin along the major Tabriz basement fault.

Introduction The Urumieh-Dokhtar Magmatic assemblage includes various volcanic and intrusive rocks from Eocene to the Pleistocene. The dominant theory in describing the tectonomagmatic environment of the Urumieh-Dokhtar Magmatic assemblage emphasizes the formation of calc-alkaline rocks from Eocene to Miocene as a result of subduction in an active continental margin tectonic environment. Volcanic activities after the Miocene are observed to a smaller extent in some parts of the Urumieh-Dokhtar Magmatic assemblage, including in Bijar, Shahrbabak, and Dehaj (Stern et al., 2021). These activities are characterized by the formation of Pliocene andesite-dacite rocks and Pleistocene andesite-basalt rocks in the Dehaj area. Post-collision magmatism in the Dehaj region is calc-alkaline and the subduction process influences its origin before the Miocene (Pang et al., 2016). In this research, the origin and petrogenetic evolution of Pliocene hyalo-andesitic rocks are studied using field investigation, geochemical data of rare elements, and isotopic ratios (87Sr/86Sr and 143Nd/144Nd) in the Dehaj area. This knowledge can help to understand the tectonic events of the Urumieh-Dukhtar Magmatic assemblage Geology of the area Hyallo-andesites of Dehaj, which are located in the northwest of Kerman province, SE part of the Urumieh-Dukhtar Magmatic assemblage. Tectonically, this area is very active and is located between Anar and Dehshir faults. The Pliocene volcanic phase is the most important magmatic activity has caused the formation of andesitic to dacite volcanic and semi-volcanic rocks in the region. Pliocene hyalo-andesites of Dehaj have also been exposed in the form of several outcrops in the vicinity of the Aj volcanic peaks. Pliocene hyalo-andesites of Dehaj are also exposed in the form of several outcrops near the Aj volcanic peaks. Hyallo-andesites are composed of a lava unit with a thickness of fewer than 10 meters on the underlying pyroclastic unit. Research Method Forty rock samples of Dehaj hyalo-andesites were collected during the field visit. After petrographic studies, thirty samples were selected for XRF and ICP-MS chemical analysis. The Middlemost (1989) method was performed to separate total iron into FeO and Fe2O3. Five samples were used to calculate isotopic ratios of strontium and neodymium. Petrography Pliocene hyalo-andesites of Dehaj are dark gray to black with a fine grain texture. Petrographically, the rocks under study, are formed from plagioclase microlites and very fine brown hornblende crystals in a cryptocrystalline and glassy matrix, and quartz crystal is not visible. The hyallo-andesitic rocks of Dehaj have disequilibrium textures, including sieve texture and oscillatory zoning in plagioclase microphenocrysts. Geochemistry Pliocene hyallo-andesitic rocks of Dehaj are classified in the dacite range and the andesite-dacite boundary based on the TAS classification (Le Bas et al. 1986). Based on SiO2 versus Na2O+K2O, AFM, and K2O versus SiO2 diagrams, these rocks are calc-alkaline with moderate potassium nature. LILE elements such as Sr, K, Rb, Ba, and Th showed enrichment, and HFSE, especially Nb, Ta, and Ti presented depletion. The primitive mantle-normalized multi-element diagram showed the positive anomaly of Sr and the negative anomaly of Nb. Chondrite-normalized REE patterns showed enrichment of LREE compared to HREE with La/Yb>9 and Sm/Yb>1. 8 ratios without any positive or negative Eu anomalies. The initial ratios calculated for 87Sr/86Sr varied from 0. 704498 to 0. 704967 and for 143Nd/144Nd from 0. 512821 to 0. 512842. The calculated values of ℇNd also vary between +3. 55 and +3. 98. Discussion Geochemical features including high amounts of strontium (Sr>750 ppm), low amounts of yttrium (Y<8ppm) and HREE, high Sr/Y ratio, and the strongly fractionated pattern of REE without Eu anomalies, define the adakitic nature of Dehaj hyallo-andesites. Enrichment in LILE elements and depletion in HFSE elements (i. e., Nb, Ta, Ti) in Dehaj adakites show the connection of these rocks with the pre-Pliocene subduction environment. High values of Sr and Rb/Sr ratios between 0. 02 and 0. 04 and La/Yb>10 along with isotopic ratios of 87Sr/86Sr and 143Nd/144Nd as well as positive values of ℇNd (+3. 55 to +3. 98) demonstrate the hyalo-andesitic rocks of Dehaj were formed as a result of the melting of the oceanic slab. Several reasons indicate the presence of garnet in the origin of the Pliocene adakites of Dehaj and the remaining of this mineral in the slab resulting from partial melting, which also represents the eclogite composition of the source rock. These reasons include values of Y<8ppm and Yb<0. 76ppm and the sloping pattern of REE elements with La/Yb>9 and Sm/Yb>1. 8 ratios. The melting process of the eclogite oceanic plate occurred at the same time or following the tectonic collision between the Central Iranian and Arabian tectonic plates during the Miocene-Pliocene. Conclusion Pliocene hyallo-andesitic rocks of Dehaj were created as a monogenetic magmatic activity. Geochemical evidence indicates that the partial melting of subducting oceanic crust is the origin of silica-rich Dehaj adakites. The Pliocene Dehaj adakites formed after the cessation of Neotethys subduction and in a tectonic environment following the collision. Thinning and separation of the subducting oceanic crust and sinking into the asthenosphere gave rise to melting conditions. These events have occurred in an active tectonic environment and simultaneously with the formation of numerous faults. The occurrence of numerous outcrops of Pliocene volcanic rocks along with Pliocene hyallo-andesitic lavas and Pleistocene basaltic lavas in the study area compared to nearby areas indicates the presence of multiple fractures in the crust of this area. These fractures have caused the rapid ascent of adakite melt from the subducting oceanic crust. During the ascent, the adakite melt has been contaminated by the upper metasomatized mantle and crust to a small extent.