Two-sided asymmetric subduction; implications for tectonomagmatic and metallogenic evolution of the Lut Block, Eastern Iran

West directed subduction zones show common characteristics, such as low structural elevation, deep trench, steep slab and a conjugate back-arc basin that are opposite to those of the east directed subduction zones. The tectonomagmatic and metallogenic setting of the Lut Block is still a matter of debate and several hypotheses have been put forward. Despite some authors denying the influence of the operation of Benioff planes, the majority propose that it occurred beneath the Afghan Block, while others consider that oceanic lithosphere was dragged under the Lut Block. Cu-Au porphyry deposits seem to occur in an island arc geotectonic setting during the middle Eocene while Mo-bearing deposits are coincident with the crustal thickening during Oligocene. We introduce new trace element and isotope geochemical data for granitoids and structural evidences testifying the two-sided asymmetric subduction beneath both Afghan and Lut Blocks, with different rates of consumption of oceanic lithosphere

Quantitative prenatal growth of the cervical sympathetic trunk components in sheep (Ovis arise) during the foetal period

Background: Six liner measurements of constant cranial cervical ganglion (CCG), three inconstant main, first, second middle cervical ganglia (MG, MG1, MG2), and interganglionic branch (IGB) were taken to determine normal foetal growth rates and patterns of cervical sympathetic trunk (CST) components in different gestational ages. Materials and methods: Forty sheep foetuses of both sexes aged from 60 to 140 days were divided into four groups and 80 sides of foetuses were examined under a stereomicroscope using a digital calliper. Results: Following findings were obtained: 1) There was no significant difference for the values between sex and body side among all age groups, although sex and laterality differences in CST length and laterality differences in IGB total length and MG1 width were found regardless of age groups. 2) Correlations between dimensions of CST components and crown-rump length (CRL) were always positive during foetal period and decreased with increasing foetal age. 3) The highest growth rate in CST components in foetal sheep took place in the youngest age group because of rapid growth rates in lengths of IGB and CCG. Conclusions: Based on these detailed findings, comparative prenatal growth rates and patterns of animal organs and body, embryological and histological data as well as neurovertebral relationships among cervical parts of sympathetic trunk, spinal cord, and vertebral column were discussed and compared with previous studies. Although allometric growth of CST in relation to CRL was constant between foetal sheep and pig, there were specific characteristics in prenatal growth of CST components in foetal sheep which were different from those of foetal pig. It seems that only growth pattern in length of CST in sheep during foetal period follows the same growth pattern of CRL, body weight, and length of cervical parts of spinal cord and vertebral column

Epidemiological survey of patients with a carpal tunnel syndrome referred to Sina Hospital in Hamedan during 2014-2016

Background: Carpal tunnel syndrome is a common mono-neuropathy with various causes. This study aimed at evaluating the epidemiology of patients with the carpal tunnel syndrome referred to Sina Hospital in Hamedan City, Iran. Materials and Methods: In this descriptive-cross sectional study, 300 patients (600 hands) suffering from paresthesia, pain and weakness of the first to third finger were studied. Diagnosis and severity of the disease was evaluated according to history, examination and electro-diagnostic studies. Afterall the data were collected. Results: This study was conducted on 230 (76.7) females and 70 (23.3) males with the mean ages of 47.3±17.4 and 49.1±20.2 years, respectively (P=0.224). Sixteen of them were left-handed and the rest were right-handed. Also, 113 of the patients had risk factors such as diabetes with the prevalence of 18.1 and hypothyroidism with 6.4 as the most common ones. The most common occupations were carpet weaving and milking with prevalence rates of 19.4 and 13.3, respectively. In electro-diagnostic findings, 57 of the patients had moderate involvement and 16.6 had severe involvement. The Phalen and Tinel test was positive in 32.2 of the patients and negative in 32.2 of the cases. There was a relationship between the severity of involvement and probability of a positive Phalen and Tinel test. Conclusion: Considering that 76 of the cases were women and among jobs, after housekeeping, carpet weaving and milking are the most common ones, paying more attention to these people and designing the proper work tools (especially carpet weaving and milking tools) as well as training of the housewives are recommended to prevent this syndrome

U-Pb Geochronology, Sr–Nd Geochemistry, Petrogenesis and Tectonic Setting of Gandab Volcanic Rocks, Northeast Iran

This paper addresses U-Pb geochronology, Sr-Nd geochemistry, petrogenesis and tectonic setting in the Gandab volcanic rocks. The Gandab volcanic rocks belong to the Sabzevar zone magmatic arc (northeastern Iran). Petrographically, all the studied volcanic rocks indicate porphyritic textures with phenocrysts of plagioclase, K-feldespar, hornblende, pyroxene, and magnetite which are embedded in a fine to medium grained groundmass. As well, amygdaloidal, and poikilitic textures are seen in some rocks. The standard chemical classifications show that the studied rocks are basaltic trachyandesite, trachyandesite, trachyte, and trachydacite. Major elements reveal that the studied samples are metaluminous and their alumina saturation index varies from 0.71 to 1.02. The chondrite-normalized rare-earth element and mantle-normalized trace-element patterns show enrichment in light rare-earth elements (LREE) relative to heavy rare-earth elements (HREE) and in large ion lithophile elements (LILE) relative to high field strength elements (HFSE). As well they show a slightly negative Eu anomaly (Eu/Eu* = 0.72 – 0.97). The whole-rock geochemistry of the studied rocks suggests that they are related to each other by fractional crystallization. LA-MC-ICP-MS U-Pb analyses in zircon grains from two volcanic rock samples (GCH-119 and GCH-171) gave ages ranging of 5.47 ± 0.22 Ma to 2.44 ± 0.79 Ma, which corresponds to the Pliocene period. In four samples analysed for Sr and Nd isotopes 87Sr/86Sr ratios range from 0.704082 to 0.705931 and εNd values vary between +3.34 and +5. These values could be regarded to as representing mantle derived magmas. Taking into account the comparing rare earth element (REE) patterns, an origin of the parental magmas in enriched lithospheric mantle is suggested. Finally, it is concluded that Pliocene Gandab volcanic rocks are related to the post-collision environment that followed the Neo-Tethys subduction

Relationship between biological egg characteristics and female brood fish in stellate sturgeon, Acipenser stellatus Pallas, 1771 (Pisces: Acipenseridae) in the Southeast Caspian Sea, Iran

Fecundity is one of the important indicators of reproduction biology in fishes especially in rearing and restocking management of endangered species such as sturgeon. The fecundity of stellate Sturgeon (Acipenser stellatus Pallas, 1771) was studied in 50 specimens captured by gill net (mesh size= 100 mm) and seine net in different fishing areas along the southeastern part of the Caspian Sea from October 2004 through June 2005.Some biological characteristics of eggs (including diameter, surface-to-volume ratio of egg) and of fish (including age, fork length, weight, fecundity and gonadosomatic indices) were determined, and the relationship between them was defined. The results obtained showed that eggs were in stage F5 of development, and mean fork length, weight, age, fecundity and gonadosomatic indices were 125.26±8.01 (cm), 10.3±1.97 (kg), 12±1.34 (years), 170730±43211.11 and 20.88±3.19 (%), respectively. Also, the average egg diameter and surface-to-volume ratio were 2.92±1.44 (mm) and 2.06±0.12 (mm-1), respectively. Positive correlation was detected between egg diameter and surface, and volume, while negative correlation was foun between egg diameter and surface-to-volume ratio. Weight, length and age have linear relationships with absolute fecundity and age was the best predicator of fecundity (r2= 0.848, F=27.962 and P value 0.003)

Effect of parasite infection with Posthodiplostomum cuticola (Nordmann, 1832) on fish growth rate in Zaringol Stream in Golestan Province

This study investigated the effect of parasite infection with Posthodiplostomum cuticola on fish growth rate in Zaringol Stream in Golestan Province. A total number of 447 fish specimens (173 Capoeta capoeta gracilis, 111 Alburnoides eichwaldii, 131 Paracobitis malapterura, 32 Neogobius fluviatilis) were captured by electrofishing during December 2009 to September 2010. Total number of parasite on fish body was counted by investigating internal organ and surface of skin and branch. Results showed that slope of regression curves and condition factor were significantly lower in infected C. c. gracilis. N. fluviatilis was the most abundant infected fish in Zarringol Stream. It seems that it's feeding dependence on benthos makes this fish more susceptible to infection by parasite

Petrography, geochemistry and tectonic significance of the Mahoor granitoids (Lut Block, Eastern Iran)

The Mahoor granitoids are Cu–Zn-bearing porphyries that outcrop in the central part of the Lut Block, about 135 km south-west of Nehbandan (eastern Iran). These granitoids occur mainly as dykes and stocks that intrude Eocene volcanics. Petrographically, all the studied intrusives display porphyritic textures with mm-sized phenocrysts, most commonly of plagioclase and hornblende, embedded in a fine-grained groundmass with variable amounts of plagioclase, hornblende, clinopyroxene, quartz and opaques. Hydrothermal alteration affected these granitoids, as revealed by the common occurrence of sericite, chlorite, sphene/leucoxene, epidote and calcite. Chemical classification criteria show that the intrusives may be named as gabbrodiorites, diorites, monzodiorites and tonalites. Major element geochemistry reveals that all the studied lithologies are typically metaluminous (A/CNK ≤ 0.94) and, in addition, suggest, that they constitute a suite belonging to the high-K calc-alkaline series. Magnetic susceptibility (1485 × 10-5 SI) together with mineralogical and geochemical features show that they belong to magnetite granitoid series (I-type). In primitive mantle-normalized trace element spiderdiagrams, the analysed samples display strong enrichment in LILE compared to HFSE (15.5 ≤ RbN/YN ≤ 45.9), accompanied by negative anomalies of Nb, Ta and Ti. REE chondrite-normalized plots show slight to moderate LREE enrichment (4.9 ≤ LaN/LuN ≤ 8.4) and negative Eu anomalies (Eu/Eu* ratios vary from 0.65 to 0.88). Tectonic characteristics also indicate that the study area is emplaced in a volcanic arc setting. The whole set of geochemical data suggest that the Mahoor granitoids are co-genetic, belong to the calc-alkaline series and have been originated in an active continental margin setting. Sulfide mineralizations (pyrite, chalcopyrite and sphalerite) related to these granitoids are common and occur both disseminated and as hydrothermal veins, indicating a high mineralization potential for this area

Fluid inclusion geothermometry of various alteration – mineralization zones of Chah-shaljami prospect, Eastern Iran

منطقه اکتشافي چاهشلغمي در خراسان جنوبي و در کمربند آتشفشاني – نفوذي بلوک لوت قرار گرفته است. تودههاي نيمه عميق گرانيتوئيدي مربوط به اليگوسن، درون تواليهاي آتشفشاني - پيروکلاستيک ائوسن نفوذ کردهاند. انواع کانيهاي دگرساني شامل آلونيت، ژاروسيت، کلريت، ديکيت، سريسيت، مونتموريلونيت، کوارتز و اکسيدهاي آهن شناسايي شدهاند. کانيسازي شامل پيريت، آرسنوپيريت، موليبدنيت، کالکوپيريت، اسفالريت، گالن و انارژيت است. ميزان دما و شوري بالاي سيالات درگير در زون دگرساني سيليس - کلريت ميتواند در تعيين مرکز سيستم کانيسازي در اکتشافات بعدي مورد استفاده قرار گيرد. دما و شوري سيالات به سمت زون دگرساني کوارتز حفرهاي در حال کاهش است که احتمالا نشان دهنده افزايش دخالت آبهاي جوي ميباشد. شواهد زمينشناسي، دگرساني، کانيسازي و تحول سيالات هيدروترمال نشان دهنده کانيسازي اپيترمال سولفيداسيون بالا مرتبط با سيستم پورفيري عمقي در منطقه ميباشد. کليد واژهها: بلوک لوت، آلونيت، سيالات درگير، اپيترمال.Chah-shaljami exploration area is located in the Southern Khorasan and belongs to the Lut Block volcanic-plutonic belt. Oligocene subvolcanic granitoids intruded into Eocene volcanic - volcaniclastic sequences. Alteration minerals include alunite, jarusite, chlorite, dickite, sericite, montmorillonite, quartz and iron oxide. Mineralization includes pyrite, arsenopyrite, molybdenite, chalcopyrite, sphalerite, galena and enargite. High temperature – salinity of fluid inclusions from sericite alteration is an indicator that can direct the next exploration toward the mineralization center. Temperature – salinity of fluid inclusions decrease toward the vuggy quartz alteration which indicate the increase of the role of meteoric fluids. The gathered data on alteration, mineralization and hydrothermal fluids together with field evidence evidence indicate that the high-sulfidation epithermal mineralization is related to the deep porphyry system in the area

Hydrothermal fluids evolution from various alteration – mineralization zones of Dehsalm porphyry type system, Lut block, Eastern Iran

منطقه اکتشافي دهسلم در خراسان جنوبي و در کمربند آتشفشاني – نفوذي بلوک لوت قرار گرفته است. تودههاي نيمه عميق حدواسط تا اسيدي مربوط به اليگوسن، درون تواليهاي آتشفشاني، ماسهسنگ و سيلتستون ائوسن نفوذ کردهاند. زونهاي دگرساني شامل انواع پتاسيک، پروپليتيک، سريسيت- رسي، اپيدوتي، سريسيت - کلسيت - سيليس و سيليسي ميباشند. کانيسازي بصورت رگه – رگچهاي و پراکنده شامل مگنتيت، پيريت، موليبدنيت، کالکوپيريت، بورنيت، طلا، آرسنوپيريت، اسفالريت، گالن، کوليت، ديژنيت و کانيهاي سولفوسالت ميباشد. مطالعه سيالات درگير تاثير فرايندهاي جوشش، ناآميختگي، سرد شدن و رقيق شدگي توسط آيهاي جوي را طي تحول سيالات کانهساز نشان داده است. ميزان دما و شوري سيالات درگير از زون دگرساني پتاسيک به سمت زون دگرساني سريسيتي - رسي در حال کاهش است که احتمالا نشان دهنده افزايش دخالت آبهاي جوي ميباشد. شواهد زمينشناسي، دگرساني، کاني- سازي و تحول سيالات هيدروترمال نشان دهنده کانيسازي سيستم پورفيري در منطقه ميباشد. کليد واژهها: بلوک لوت، سيالات درگير، جوشش، سيستم پورفيريDehsalm exploration area is located in the Southern Khorasan and belongs to the Lut Block volcanic-plutonic belt of the Lut block. Oligocene intermediate to acidic subvolcanic rocks intruded into Eocene volcanic, sandstone and siltstone sequences. Alteration zones include potassic, propylitic, sericite – calcite – silica, sericite – argillic, epidote and silicification. Vein – veinlet and disseminated mineralization comprise magnetite, pyrite, molybdenite, chalcopyrite, bornite, arsenopyrite, sphalerite, galena, covellite, digenite and sulfosalts. Fluid inclusion studies have shown the affect of boiling, fluid immiscibility, cooling and dilution processes by meteoric fluids during the evolution of mineralizing fluids. Temperature – salinity of fluid inclusions decrease from potassic through sericite – argillic alteration which indicate the increase of the role of meteoric fluids. The gathered data on alteration, mineralization and hydrothermal fluids together with field evidence indicate that a porphyry type mineralization system occurs in the area