Publication Date: 2021
Waste Management and Research (0734242X)39(2)pp. 325-350
The present study evaluated and selected the best location among susceptible landfill sites in Rudbar County using 27 criteria, as the maximum effective criteria, in the decision-making process. The emergence and comparison between the two methods of fuzzy and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) with an engineering–geological approach have been conducted to obtain the best results. In this regard, inappropriate regions for landfill construction have been restricted after the conflation of two maps based on the restriction criteria. Then, the direction of prevailing winds and proper area for landfill construction was investigated for a 20-year perspective, and the regions that had more than 35-hectare area and were not located in the direction of the prevailing winds have been identified as responsive sites for landfill construction. Ultimately, selected susceptible regions were prioritized separately based on the TOPSIS and fuzzy methods. To ascertain the accuracy of the results and the reality of the resulted models, complementary field studies, geotechnical digging, and engineering–geological experiments have been used as verification parameters. According to the results of the verification, the fuzzy model having maximum matches with the verified data has been suggested for prioritizing susceptible regions. © The Author(s) 2020.
Ernst, A.,
Königshof, P.,
Bahrami, A.,
Yazdi, M.,
Boncheva, I. Publication Date: 2017
Palaeobiodiversity and Palaeoenvironments (18671608)97(3)pp. 541-552
A bryozoan fauna from the Late Devonian (Frasnian) of the Bahram Formation of the Zefreh section in central Iran contains four species: three trepostomes and one rhabdomesine cryptostome. Two species are new: the trepostome Coeloclemis zefrehensis sp. nov. and the rhabdomesine cryptostome Euthyrhombopora tenuis sp. nov. The trepostome species Cyphotrypa definita Morozova, 1960 and Anomalotoechus ramosus Morozova, 1960 were recorded previously from the Upper Devonian (Frasnian) of the Kuznets Basin. The genera Coeloclemis and Euthyrhombo-pora are recorded from the Devonian for the first time. The fauna is dominated by the erect ramose Euthyrhombopora tenuis sp. nov., with rare occurrences of the massive Cyphotrypa definita Morozova, 1960. The bryozoans indicate low to moderate water energy environment of middle to outer ramp position. © 2017, Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg.
Publication Date: 2019
Historical Biology (08912963)31(5)pp. 574-580
Fossil insects are very rarely found in sediments of deep marine origin. Nevertheless they can be of great interest to trace past events such as trans-oceanic migrations. Here we document the first fossil insects from Iran, viz. several alate ants dead during mating swarms and a migratory locust, found in the pelagic Oligocene sediments of the Zagros Mountains. This locust represents the first putative indication of insect migrations between the Arabian-African and Asiatic continents through the Parathetys, probably in relation with the development of open grassland biotas in these areas. © 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group.
Publication Date: 2018
Journal of Asian Earth Sciences (18785786)166pp. 35-47
This paper presents petrographic and U-Pb LA-ICP-MS isotopic data of a single peraluminous intrusion (alkali-feldspar granite of Airekan) with partial gneissic foliation on the north western margin of the Yazd Block in the west of the Central-East Iranian Microcontinent (CEIM) to discuss the evolution of this terrain. This intrusion typically suggests a continental collision orogenesis along the northern frontier of Gondwana in the CEIM. The U-Pb dating of zircons indicates that Airekan granite has a distinctive inherited magmatic component at ∼518.2 ± 4.9 Ma but zircons with 892, 679, 614 and 554 Ma ages. These zircons were likely to be ultimately sourced from neighboring Neoproterozoic – Cambrian leucogranite terrains, similar to the other localities in the northern margin of Gondwana, along the Alpine-Himalayan belt from Europe, Turkey, NE Iran, CEIM, Pakistan, India to southern Tibet. The zircons and overgrowths around the inherited components with igneous morphology indicate a plutonism at Lower Ordovician (∼483 ± 2.9 Ma). Petrographic features and morphology of zircon crystals indicate that partial resetting of the U-Pb system in zircons have occurred at ∼382.6 ± 3.2 Ma in Devonian, during the Paleo-Tethys evolutions in Khur region (Anarak-Jandaq terrane) in the southern active margin of Laurasia. © 2018 Elsevier Ltd
Publication Date: 2019
Geotechnical and Geological Engineering (09603182)37(5)pp. 4435-4446
Determination of optimum distance between twin tunnels is very important to reduce the construction’s costs in road or railway projects. When two tunnels are located close together, stress concentration in their space increases and it is possible that plastic zones would be merged. In mining engineering and especially underground mining applications, this zone (the distance between twin tunnels) is called pillar and there are some empirical models to estimate its width. However, these models are not completely suitable for all rock types and different tunnel geometries. In this study, an attempt was made to present a new criterion for the design of twin tunnels. It is based on ground reaction curve and takes width to height ratio (w/h) and shear strain of the pillar (obtained by numerical modeling) into consideration. Strain magnitude observed when normal stress (σ1) in the pillar reaches the value of compressive strength of the rock mass (σcm), denotes the allowable ratio of width to height (w/h) which shows the optimum distance between twin tunnels. Pooneh twin tunnels which located in Iran were selected as a case study. These are road twin tunnels excavated in layers of nine different zones (Arak–Khoramabad Expressway). Results of the suggested method show a good agreement between the pillar dimensions seen in the case study and the present method. Taking all aspects of geomechanical and geometrical characteristics of the tunnels into consideration, it is one of the main advantages of this method. © 2019, Springer Nature Switzerland AG.
Publication Date: 2009
Historical Biology (08912963)21(3-4)pp. 215-227
Platform carbonate sediments of Oligocene-Miocene age (Asmari Formation) in the Zagros Basin (SW Iran) have been investigated in order to determine their paleoecology and depositional environment. The Zagros Basin is the result of the opening and closure of the Neo-Tethys Ocean along the northeastern border of the Arabian Plate. The thick sedimentary sequences of the Zagros Basin contain rocks ranging in age from Cambrian to recent. The geological evidence suggests that the region was part of a passive continental margin, which subsequently underwent rifting in the Permo-Trias and collision in the Late Tertiary. The Asmari carbonate system was dominated by foraminifera and corallinacean assemblage. Based on the distribution of the larger foraminifera, four assemblage zones have been recognised. Facies analysis allowed the recognition of nine microfacies types that are grouped into three depositional environments that correspond to the inner, middle and outer shelf. The biota assemblage of the Asmari Formation suggests that carbonate sedimentation took place in tropical waters and oligotrophic to slightly mesotrophic conditions. Our detailed analysis of microfacies and paleoecology shows that the Asmari Formation deposited on a carbonate open shelf dominated by heterozoan and, subordinately, photozoan skeletal assemblage. © 2009 Taylor & Francis.
Morsali, M.,
Nakhaei, M.,
Rezaei, M.,
Hassanpour j., J.,
Nassery, H. Publication Date: 2017
Quarterly Journal of Engineering Geology and Hydrogeology (14709236)50(2)pp. 126-132
The accurate estimation of groundwater head in tunnels is a critical issue in tunnelling and in designing the lining and its sealing potential. This study was conducted to estimate the actual groundwater pressure on the lining of the tunnel in the Karaj-Tehran water conveyance tunnel. High water pressure (over 400 m) was estimated from the water level in boreholes whereas low water pressure (5 m) was measured at piezometers installed in the tunnel. In this regard, estimation of the groundwater head based on the water inflow into the tunnel is considered as a new approach. Water head and permeability, as fundamental parameters for the estimation of water inflow into the tunnel, are estimated through analytical methods and experimental studies prior to the tunnel boring. Because the actual data for water inflow into the tunnel are available, the water head can be estimated based on the volume of infiltrated water. Using these techniques, the water pressure along the tunnel axis is estimated to be between 5 and 170 m in different zones. This method is recommended for water head estimation in other tunnels with similar geological properties. © 2017 The Author(s).
Publication Date: 2014
Bollettino della Societa Paleontologica Italiana (03757633)53(1)pp. 27-37
The deep-sea hatchetfish clade includes some of the most bizarre stomiiforms, which are characterized by a deep and strongly compressed body, with vertically flattened silvery sides. This peculiar group of mesopelagic fishes consists of three extant and three extinct genera that appeared in the record in the Middle Eocene. A new genus and species of deep-sea hatchetfish, Eosternoptyx discoidalis n. gen. et sp., is described from the Middle to Late Eocene deposits of the Pabdeh Formation exposed a few kilometres east of the city of Ilam, Zagros Basin, Iran. The new deep-sea hatchetfish taxon from Ilam is based on a partially complete specimen in part and counterpart characterized by a remarkably discoid physiognomy of the body and a unique combination of features, including: 28 (13+15) vertebrae; eight pairs of pleural ribs; two posteriormost pleural ribs shortened not reaching the ventral margin of the abdominal keel; six supraneurals; dorsal blade absent; dorsal fin contains 18 rays; first dorsal-fin pterygiophore very large and protruding externally beyond the dorsal profile of the body; possession of two preanal spines; anal-fin origin opposite to dorsal-fin origin; posttemporal and supracleithrum not fused; posttemporal spine absent; body naked. The comparative osteological analysis suggests that Eosternoptyx n. gen. appears to be intermediate between the basal genus Polyipnus and the more derived deep-sea hatchetfish genera Argyropelecus, Discosternon, Horbatshia, Polypnoides, and Sternoptyx.
Ghadirpour, M.,
Torabi, G.,
Shirdashtzadeh, N.,
Meisel, T.C.,
Morishita, T. Publication Date: 2025
Journal of African Earth Sciences (1464343X)228
The Eocene Kalut-e-Ghandehari (KG) pluton, located in the Central Eastern Iranian Microcontinent (CEIM), intrudes the Ashin Mesozoic ophiolite and Middle Eocene volcanic rocks. Petrographic and geochemical analyses reveal a calc-alkaline, metaluminous intermediate to mafic composition ranging from gabbro to monzonite. The rocks exhibit characteristic REE and HFSE patterns indicative of subduction-related magmatism. The KG pluton is composed of plagioclase (An = 34–60 %), Alkali-feldspar (Or = 70.8–96.1 %), diopside (Mg# = 0.71–0.90), phlogopite (Fe# = 0.3), and opaque minerals. Geochemical evidence (e.g., enrichment of LREE, LILE (e.g., Cs, Ba, Rb, Th, U), Zr, and Hf; depletion of HREE, Ti, Nb, and Ta, and Y) suggests partial melting of a lithospheric spinel lherzolite that had been previously enriched by an earlier subduction event. The geochemical similarities of parental magmas of the KG pluton and the Soheyl-e-Pakuh pluton (located in the neighboring ophiolite of Nain) indicate that both derive from a subduction-induced partial melting of a mantle peridotite. However, their magma sources temporality and spatially are in accord with eastern and western Neo-Tethys subduction-related magmatisms, respectively. Thus, the cross-cutting relationships between the pluton and the Ashin ophiolite, combined with geochronological data, support a pre-Upper Eocene closure of the eastern Neotethys oceanic crust. This finding provides valuable insights into the Cenozoic tectonic evolution of the Central Iran. © 2025 Elsevier Ltd
Publication Date: 2016
Facies (01729179)62(4)
Early Aptian Lithocodium–Bacinella floatstone facies from the central Persian Gulf were a response of the Dariyan platform to a global disturbance. Carbon- and strontium-isotope data combined with facies analysis for the Late Barremian–Early Aptian Dariyan Formation record the timing of OAE1a and provide evidence for a causal relationship between OAE1a and Lithocodium–Bacinella occurrence. Carbon isotope stratigraphy allows the correlation of OAE1a-related segments in the Dariyan carbonates with other Tethyan shallow-water platform and pelagic reference sections. Strontium-isotope stratigraphy provides a numerical age of 124.3 ± 0.1 to 124.8 ± 0.1 Ma for OAE1a, indicating earliest Aptian, in the central Persian Gulf. Correlation of carbon isotope stratigraphy and Lithocodium–Bacinella-bearing facies shows that the Dariyan L–B occurrence post-dated OAE1a. The delay in the development of the Dariyan L–B facies is ascribed to the physiographic setting and a set of regional parameters including nutrient levels, alkalinity, and tolerance of dominant carbonate producers to OAE1a. Lithocodium–Bacinella floatstone facies of the Dariyan Formation is characterized by patchy-cloudy to columnar and oncoidal morphotypes. These growth patterns reflect the environmental conditions of probable high sedimentation rate, low alkalinity, low trophic level, and high oxygenation. Lithocodium–Bacinella facies and associated foraminifera and algae suggest peritidal to lagoonal (inner ramp) conditions for the upper Dariyan interval. © 2016, Springer-Verlag Berlin Heidelberg.
Publication Date: 2025
Geopersia (22287817)15(1)pp. 119-136
The study of karst water potential is one of the most important and attractive studies of this type of distinctive landform. This study has been carried out with the aim of identification of areas of extensive karstification and consequently groundwater resource potential carbonate rocks in Iran considering the role of the chief factors affecting karst water potential. Accordingly, 25 different data layers where interrogated in a GIS platform. Subjective karst map was developed on the basis of what is considered to be a proper combination of these factors. The most important parameters are categorized to three driving factors include chemical, physical, and hydrogeological factors. Thematic map of each parameter was prepared using geographic information system (GIS). Measuring the rate and weight of the maps was performed using analytical hierarchical process (AHP), respectively. The final output map showed different zones of groundwater prospective potential, which was divided into five grades. According to the results, out of the total area of 174,000 km2 of carbonate outcrops in Iran, the highest grade of karst water potential was found in the Kopet-Dagh zone in the northeast. So, the significance of karst formations in the Kepet-Dagh region is at least as great as that of the Zagros and Alborz ranges, if not greater. Validation of karstification potential map was done with the existence and location of springs and karst aquifers in the Kopet-Dagh area. © (2025), (University of Tehran). All rights reserved.
Publication Date: 2020
Revue de Micropaleontologie (00351598)66
Developing a more precise time framework in any hydrocarbon-bearing basin is potentially of great value to geologists and reservoir modelers for better understanding the hydrocarbon reservoir zonation, and identifying unconformities. In the Asmari Formation, which is the most important Oligocene–Miocene carbonate reservoirs in Iran, broad time zonation is generally used based on larger benthic foraminifera (LBF). In this study, the biostratigraphic zonation of the Asmari intra-shelf basin is re-evaluated based on the spatial and temporal distribution of LBF (i.e., different species of Nummulites, Eulepidina, Archaias, Spiroclypeus, Miogypsinoides, Miogypsina, and Borelis) as well as Sr isotope datasets. This research proposes a new zonation to improve time resolution in the Oligocene and explains the effects of environmental factors on some index fossils and the limited range of some key fauna. The newly proposed zonation consists of one biofacies and nine biozones occurring throughout the Rupelian to Burdigalian allowing differentiating Oligo-Miocene stages, and tuning the chronostratigraphic framework of the Oligocene–Miocene deposits. Moreover, based on this new biozonation, regional-scale palaeogeographical maps of the Asmari intra-shelf basin during Rupelian-Burdigalian were officially established. © 2020 Elsevier Masson SAS
Publication Date: 2003
Ground Water (0017467X)41(5)pp. 602-607
The Theis type curve matching method and the Cooper-Jacob semilog method are commonly used for estimation of transmissivity and storage coefficient of infinite, homogeneous, isotropic, confined aquifers from drawdown data of a constant rate pumping test. Although these methods are based on drawdown data, they are often applied indiscriminately to analyze both drawdown and recovery data. Moreover, the limitations of drawdown type curve to analyze recovery data collected after short pumping times are not well understood by the practicing engineers. This often may result in an erroneous interpretation of such recovery data. In this paper, a novel but simple method is proposed to determine the storage coefficient as well as transmissivity from recovery data measured after the pumping period of an aquifer test. The method eliminates the dependence on pumping time effects and has the advantage of employing only one single recovery type curve. The method based on the conversion of residual drawdown to recovered drawdown (buildup) data plotted versus a new equivalent time (Δt X tp/tp + Δt). The method uses the recovery data in one observation point only, and does not need the initial water level h0, which may be unknown. The accuracy of the method is checked with three sets of field data. This method appears to be complementary to the Cooper-Jacob and Theis methods, as it provides values of both storage coefficient and transmissivity from recovery data, regardless of pumping duration.
Salehi, M.A.,
Moussavi-harami, R.,
Mahboubi, A.,
Fürsich, F.T.,
Wilmsen, M.,
Heubeck, C. Publication Date: 2018
Swiss Journal of Geosciences (16618734)111(1-2)pp. 51-78
The Lower Jurassic Ab-Haji Formation consists of siliciclastic strata which are widespread and superbly exposed across the Tabas and Lut blocks of east-central Iran. The formation records the geodynamic history of central Iran during the Early Jurassic in the aftermath of the main Cimmerian event (near the Triassic–Jurassic boundary) through its sedimentary facies and stratigraphic architecture and allows palaeogeographic and palaeoenvironmental reconstructions. We measured and studied three well-exposed outcrop sections and identified lithofacies and facies associations (fluvial plain, delta plain, delta front, prodelta, and shallow-marine siliciclastic shelf). The integration of all geological, stratigraphic, and sedimentological data shows a west-to-east continental-to-marine gradient within the Ab-Haji Formation. Based on thickness variations, lateral facies changes, palaeocurrent patterns, and changes in the nature of the basal contact of the Ab-Haji Formation on the Tabas and Lut blocks, we locate the fault-bounded Yazd Block in the west and the Shotori Swell at the eastern edge of the Tabas Block as provenance regions. The pattern of thickness variations, rapid east–west facies changes, and provenance is best explained by a tectonic model invoking large tilted fault blocks in an extensional basin. The basal unit shows distinct increase in grain size at the base of the Ab-Haji Formation, similar to the Shemshak Group of the Alborz Mountains (the base of the Alasht Formation) and the non-marine time-equivalent succession of the Binalud Mountains of northeastern Iran. This grain size pattern may have been caused by rapid source area uplift due to slab break-off of the subducted Iran plate in the course of the Cimmerian collision in east-central Iran. © 2017, Swiss Geological Society.
Publication Date: 2010
Boletin de la Sociedad Geologica Mexicana (14053322)62(2)pp. 207-211
Two species of decapod crustaceans are described from upper Albian sediments of Central Iran. The small mecochirid lobster-Huhatanka iranica n. sp. represents the second species of this genus, previously known from the Albian of Kansas, USA. Callianassa sensu lato is reported as an associated crustacean.
Publication Date: 2020
Zeitschrift der Deutschen Gesellschaft fur Geowissenschaften (18601804)171(4)pp. 503-519
One outcrop of the Qom Formation was measured for age determination and interpretation of palaeoenvironmen-tal conditions based on benthic foraminifera and the vertical distribution of microfacies and microtaphofacies in the Bijegan area of Iran. The study area is located about 20 km northeast of Delijan. There the Qom Formation is 162 m thick and dominantly contains thin, medium, thick bedded, and massive limestone. The formation overlies the Lower Red Formation in the Bijegan area. The upper boundary of the Qom Formation is formed by unconformably overlying recent alluvial sedi-ments. Three assemblage zones were identified. Assemblage zone 1 indicates a Rupelian age while assemblage zones 2 and 3 were deposited during the Chattian. The correlation between the curve of seawater depth changes and the distribution curve of microtaphofacies in the study area is indicative of a high energy environment (under the effect of the fair-weather wave base [FWWB] or storm wave base [SWB]) throughout the Rupelian-Chattian. Salinities are interpreted to have oscil-lated between normal marine (30–40 psu) and hypersaline (>50 psu) during deposition. The trophic conditions were mainly mesotrophic to oligotrophic. Euphotic conditions prevailed during the Rupelian and Chattian. In the Bijegan area, the Qom Formation formed in euphotic to meso-oligophotic conditions. Lagoonal and open marine environments characterise the lower section of the studied sequence (Rupelian and lower Chattian stages) and open marine conditions were dominant in the upper section of the study sequence (upper Chattian stage). Correlation of the study area with five other Rupelian-Chattian outcrops shows high sedimentation rate in the Qohrud area during the Rupelian and in the Mashhad Ardehal area during the Chattian. Throughout the Oligocene, the activity of local faults presumably affected sedimentation rates, sedimentary environments, and sea-level change in the Qohrud, Vidoje, Naragh, Bijegan, Mashhad Ardehal and Neizar areas. © 2020 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany.
Publication Date: 2011
Petrology (15562085)19(7)pp. 690-704
In western part of the CEIM (Central-East Iranian Microcontinent) (Bayazeh area, Isfahan province, Iran), a series of Paleozoic basaltic rocks, occur. Major minerals of these basalts are olivine, clinopyroxene (diopside, augite), plagioclase (albite), sanidine, amphibole (kaersutite), phlogopite, ilmenite and magnetite. Secondary minerals include epidote, pumpellyite, albite, calcite and chlorite. Olivine and clinopyroxene are as phenocryst, while feldspars are restricted to groundmass. Chemical composition of clinopyroxenes indicates crystallization during ascending of magma. Geochemical analysis of whole rock samples shows that these rocks are characterized by low SiO2 (43.21-48.45 wt %), high TiO2 (1.81-3.00 wt %) and P2O5 (0.18-0.34 wt %). Petrography, chemistry of clinopyroxenes and whole rock analyses reveal an alkaline nature of these basalts. They are enriched in alkalis (Na2O + K2O = 4.1-7.7 wt %), LILE, HFSE and LREE. The Bayazeh alkali-basalts present strong enrichment in LREE relative to HREE (La/Lu ratio = 77.6-119.6) and were dominantly derived from partial melting of a metasomatized asthenospheric garnet-amphibole lherzolite. Field relationships reveal that junction of faults in west of the Bayazeh prepared a suitable path for ascending of magma from deep regions to surface and intra-plate continental magmatism. The Paleo-Tethys subduction from lower to upper Paleozoic is too enough for mantle enrichment in volatiles and basaltic alkaline magmatisrn in upper Paleozoic of Bayazeh area. © 2011 Pleiades Publishing, Ltd.
Publication Date: 2011
Island Arc (10384871)20(3)pp. 386-400
Paleozoic lamprophyres exhibit good exposures in the western part of the Central-East Iranian microcontinent. These rocks crop out as volcanoes, dykes, and plugs. The constituent minerals are amphibole, clinopyroxene, plagioclase, K-feldspar, olivine, Cr-spinel, titanite, biotite, and ilmenite. The main textures in volcanic lamprophyres are porphyritic, trachytic, microlithic, and variolitic, whereas in dykes and plugs, intergranular texture is common. These lamprophyres are regionally metamorphosed in some areas. Petrographical and geochemical characteristics of the studied rocks suggest that they are classified as alkaline lamprophyres and camptonites. They are enriched in alkalis (Na2O+K2O), large ion lithophile elements, and light rare earth elements, and the features of trace element concentrations are similar to those of within-plate basalts. This study suggests that the lamprophyres were derived from different degrees of partial melting of metasomatized amphibole-bearing spinel lherzolite. Subduction of Paleo-Tethys oceanic crust from the Early to late Paleozoic resulted in enrichment in fluids in the mantle, and lamprophyric magmatism occurred along the minor and major faults. This limited but typical lamprophyric magmatism in a broad area of Central Iran suggests that, in spite of the long length of the Paleozoic (~250my), it was a relatively calm era from the viewpoint of magmatism in Central Iran. © 2011 Blackwell Publishing Asia Pty Ltd.
Beygi s., S.,
Talovina i.v., I.V.,
Tadayon, M.,
Pour, A.B. Publication Date: 2021
International Journal of Image and Data Fusion (19479832)12(2)pp. 155-175
Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery was used to identify argillic, phyllic and propylitic alteration zones and mapping geological structural features for porphyry copper exploration in the Kacho-Mesqal zone, Urumieh- Dokhtar Magmatic Arc, Iran. The image processing techniques such as specialised band ratio, Selective Principal Component Analysis (SPCA), and Spectral Angle Mapping (SAM) image processing methods were implemented to the visible and near-infrared and shortwave infrared bands of ASTER. Results indicate that the argillic alteration zone is broadly distributed in the granodiorite intrusion, andesitic rock, tuff breccia and ignimbrite. Phyllic alteration is mainly mapped associated with sandstone and some parts of andesitic lithology. Propylitic alteration zone is identified in andesite, sandstone, shale and marl, dacite to rhyodacite, andesite-basalt, tuff and andesite lava and granodiorite intrusion. The fracture density map shows that the argillic alteration is mostly abundant in the high-density fracture zone, whereas propylitic and phyllic zones are located in moderate to low-density fracture zones. Consequently, high potential zones for copper mineralisation in the study area are identified within the high to moderate fracture density zones associated with argillic and assemblage of argillic, phyllic and propylitic alteration zones in granodiorite and andesite units. © 2020 Informa UK Limited, trading as Taylor & Francis Group.
Publication Date: 2016
Italian Journal of Geosciences (20381719)135(1)pp. 109-119
The Paleozoic Bayazeh ophiolite is situated in the western part of the Central-East Iranian microcontinent (CEIM). This ophiolite consists of serpentinised peridotites, metagabbros, metamorphosed ultrabasic dykes, metapicrites, serpentinites and metamorphosed listwaenites which are covered by Late Paleozoic schists and marbles. The unique petrological characteristic of this ophiolite is due to regional metamorphism, which produced listwaenites by carbonation of serpentinites. The mineral association of the Bayazeh metamorphosed listwaenites is represented by amphiboles (tremolite and actinolite), carbonates (dolomite and calcite), quartz, serpentine (antigorite), chromian spinel, ferritchromite and chlorite (pycnochlorite). The main textures are nematoblastic and granoblastic. Rockforming minerals and the association of the outcrops with serpentinites indicate that the amphibole-bearing listwaenites were generated by regional metamorphism of serpentinites. The mineral assemblage of these rocks and the chemical composition of chromian spinels and amphiboles reveal that these minerals were metamorphosed under upper greenschist to lower amphibolite facies P-T conditions. Relicts of well-preserved chromian spinel cores in the studied rocks were used as a petrogenetic indicator. The high Cr and Mg values, together with the low Fe3+ and Ti contents of the serpentinite chromian spinels confirm their magmatic nature. The chemical characteristics of the investigated chromian spinels suggest that the protolith should have been a harzburgite belonging to a suprasubduction zone geotectonic setting. © Società Geologica Italiana, Roma 2016.
Publication Date: 2021
MethodsX (22150161)8
The presented article provides an experimental classification for South Pars marls (SPM), southwest of Iran, using the Schmidt hammer rebound index, marl geological classes, and SPM geo-engineering characteristics. In this regard, 45 samples of marls (rock) are selected on the studied site and tested by geotechnical in-situ and laboratory tests such as Schmidt hammer, uniaxial compressive strength (UCS), laboratory direct-shear (LDS) to estimate the geo-engineering characteristics of SPM. These specimens are categorised by Pettijohn's marl classification in 3 main groups (concluded argillaceous lime, calcareous marl, and marlstone) and established the geologic class and geo-engineering properties as well as Schmidt hammer rebound index. In the meantime, the geologic classes and the Schmidt index show the logic classification. Thus, this work attempted to prepare the experimental classification based on Pettijohn's marl classification and Schmidt rebound index for SPM. According to geotechnical experiments results, the Schmidt index shows 3 main group variations like Pettijohn's marl classification. • This method can be used to prepare the geologic status based on the Schmidt rebound index. • This method can be useful for detailed decryption of geo-engineering characteristics of different type of marls in the studied area. • This method can be used as a quick link for marl geologic status and geo-engineering features. © 2021
Publication Date: 2014
Geotechnical and Geological Engineering (09603182)32(1)pp. 205-214
Publication Date: 2020
International Journal of Hydrology Science and Technology (20427808)10(5)pp. 504-513
Various equations have been developed for assessing the hydraulic conductivity (K) based on particle size distribution. Since the percentages of fine and coarse particles in a sediment significantly influence its permeability, values of K obtained using these empirical equations are erroneous. In this research, a new and applicable equation has been advised which is based on the percentages of fine and large particles in the sample. The following relationship obtained from multiple linear regressions between values of K and corresponding particle size data: K = 0.0419 (Fk)2 – 0.1478 (Fk) + 1.5629, FK = 30Pg(2) – 3PS(0.1) + 3.2. The validity of this new presented equation has been controlled with eight new samples. Calculated values of K using this equation yield relative errors of 5% to 10% which fall in range of allowable errors. Copyright © 2020 Inderscience Enterprises Ltd.
Publication Date: 2019
Bulletin of Engineering Geology and the Environment (14359537)78(6)pp. 3959-3968
Resistance to degradation is one of the most important aggregate properties for engineering projects involving the use of aggregates. The Los Angeles abrasion loss (LAAL) test is among the common aggregate degradation tests that provide information on the quality of abrasion resistance of aggregates. In this study, the possibility of predicting the LAAL from the common aggregate tests including aggregate crushing value (ACV), aggregate impact value (AIV), density (D), water absorption (WA), porosity (P), uniaxial compressive strength (UCS), and point load index (PLI) was investigated. For this purpose, more than 200 rock aggregate samples, which included the most common types, were used. Statistical analysis was performed followed by developing simple linear and the best nonlinear and multiple regression analysis between LAAL and other common aggregate tests. The validity of the various regression equations was evaluated by multiple R (R, R2, and Adj. R2), analysis of variance (ANOVA), and standard error of the estimate (SEE). Results of the simple regression analyses indicate that ACV with R = 0.887, PLI with R = 0.687, and WA with R = 0.607 have the highest correlation with LAAL. Also, results of LAAL, ACV, and AIV could be converted to each other in different rock aggregate samples. The results of multiple and backward regression analyses showed that LAAL could be estimated using a few important variables such as ACV and P or performing simple physical tests including WA, D, and P (R = 0.905 and R = 0.850, respectively). The results of this research could be used for selecting proper rock aggregates in terms of their abrasion resistance, estimating their LAAL range at the preliminary steps of the project, and also for providing a better understanding of the relationships between LAAL and other aggregate properties. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
Publication Date: 2019
Bulletin of Engineering Geology and the Environment (14359537)78(3)pp. 1555-1563
Rock aggregates are the most fundamental material of highway, railroad, and other construction activities. The quality of rock aggregates for a given usage is determined by many different test methods, one of the most important of which is the Los Angeles abrasion (LAA) test as it is used to evaluate the resistance to abrasion and wear of aggregates for such applications as railroad ballast, base course material, and asphalt and concrete aggregates. In this study, the relationship between rock texture and LAA loss was investigated for 26 sources of carbonate aggregates found in Iran which constitute the most commonly quarried crushed rock. Regression analyses were used to determine whether rock texture was a useful predictor of LAA loss. The texture of rock aggregate was quantified by texture coefficient (TC), which can be used to put a value on rock texture with studies carried out on the rock thin section using image analysis. In addition, the effects of textural parameters including area weighting of grains or packing density, grain shape, grain elongation, circularity, and orientation of mineral grains, and also TC on the LAA loss were evaluated. Although the results show that weak relationships exist between textural parameters and LAA loss, a strong relationship exists between TC and LAA loss. The results indicate that many textural parameters, together with TC, can be interpreted as rock texture which influences the LAA loss. Also, the results indicate a strong negative correlation between LAA loss and TC, and can be used to predict LAA loss in practical applications. © 2017, Springer-Verlag GmbH Germany, part of Springer Nature.
Alaminia, Z.,
Tadayon, M.,
Finger f., ,
Lentz, D.R.,
Waitzinger m., Publication Date: 2020
Ore Geology Reviews (01691368)117
The Abbas-Abad volcano-sedimentary-hosted Fe-Cu skarn deposit, NE Isfahan, is one of the most important skarns in the central Urumieh-Dokhtar magmatic arc. It was formed along the contact with the Dorojin granitoid massif next to the Zefreh Fault. The plutonic rocks are of I-type, volcanic arc affinity with normal-K, metaluminous, calc-alkaline to calcic quartz diorite, tonalite, and granodiorite, similar to many other Fe-type skarn-related granitoids worldwide. The parent magma involved in this skarn system is high temperature and relatively oxidized. Amphibole geobarometery in quartz diorite yielded a crystallization pressure lower than 200 MPa (2 kb, ~7 km) at 724° to 785 °C. Granitoid compositions around the ore deposit are mainly granodiorite. U-Pb zircon dating yields Early Miocene ages of 23.0 ± 1.6 Ma for a quartz dioritic rock and 21.3 ± 1.5 Ma for a tonalitic sample. The injection and cooling of the granodiorite produced a hornblende hornfels aureole with endoskarn. Paragenetic relationships and microprobe data indicate that Abbas-Abad calcic skarn evolution can be subdivided into three stages as follow: (I) Prograde skarn associated andradite-rich garnet (Adr93-98Grs0-4Spe1-2) and pyroxene, (II) Retrograde skarn starting with garnet (Adr53-69Grs28-43Spe2-4), magnetite, and sulfide minerals associated with calcic-alteration, and (III) Post-ore with pyrite, chalcedony, epidote, quartz, calcite, and zeolite veinlets. Textural and compositional studies of garnet and magnetite from the garnet-bearing exoskarn zone reveal the multiple events associated with skarn formation. Garnets are characterized by low TiO2 and relatively high CaO that are indicative of a calcareous wall-rock among Eocene volcaniclastic rocks. They are grouped into garnet-1 (low w/r) and garnet-2 (inverse zoning at high w/r) with notable Cu-contents (up to 743 ppm). Petrographically, magnetite morphology is divided into fine-grained granular, needle-like, and polycrystalline aggregates. Mineral chemistry of needle-like type reveals impure components (Al2O3, CaO, and SiO2). This type formed from dissolution-reprecipitation processes during a stage of reequilibration in the skarn system. Mixing with cooler external fluid (rich in oxygen and poor in Fe2+) is reflected in individual features during infiltration metasomatism during garnet and magnetite growth, such as oscillatory zoning and needle-like textures. Thus, we infer increasing pH (decreasing acidity) and decreasing T related to carbonate neutralization reactions affecting Fe- and Cu-chloride complexing as the main controls on mineralization. The structural studies of the area show that movement of the dextral transtensional Zefreh Fault provide local zones for emplacement of Dorojin granitoid during the Early Miocene. Consequently, the dextral transtensional Zefreh Fault and dextral transpression associated with the Marbin-Rangan Fault uplifted the skarn and host units and Dorojin body under the roughly N-S directed maximum compression direction. Furthermore, the interplay of Zefreh and Marbin-Rangan faults within the N-S regional compressional regime formed an anticlinal structure that exposed the Dorojin body within the core. © 2020 Elsevier B.V.
