264 research outputs found
Petrology and geochemistry of mafic magmatic rocks from the Sarve-Abad ophiolites (Kurdistan region, Iran): Evidence for interaction between MORB-type asthenosphere and OIB-type components in the southern Neo-Tethys Ocean
No full textThe Sarve-Abad (Sawlava) ophiolites crop out in the Main Zagros Thrust Zone and represent remnants of the Mesozoic southern Neo-Tethys Ocean that was located between the Arabian shield and Sanandaj-Sirjan continental block. They consist of several incomplete ophiolitic sequences including gabbroic bodies, a dyke complex, and pillow lava sequences. These rocks generally range from sub-alkaline to transitional character. Mineral chemistry and whole-rock geochemistry indicate that they have compositions akin to enriched-type mid-ocean ridge basalts (E-MORB) and plume-type MORB (P-MORB). Nonetheless, the different depletion degrees in heavy rare earth elements (HREE), which can be observed in both E-MORB like and P-MORB like rocks enable two main basic chemical types of rocks to be distinguished as Type - I and Type - II. Type - I rocks are strongly depleted in HREE (YbN 9.0). Petrogenetic modeling shows that Type - I rocks originated from 7-16% polybaric partial melting of a MORB-type mantle source, which was significantly enriched by plume-type components. These rocks resulted from the mixing of variable fractions of melts generated in garnet-facies and the spinel-facies mantle. In contrast, Type - II rocks originated from 5-8% partial melting in the spinel-facies of a MORB-type source, which was moderately enriched by plume-type components. A possible tectono-magmatic model for the generation of the southern Neo-Tethys oceanic crust implies that the continental rift and subsequent oceanic spreading were associated with uprising of MORB-type asthenospheric mantle featuring plume-type component influences decreasing from deep to shallow mantle levels. These deep plume-type components were most likely inherited from Carboniferous mantle plume activity that was associated with the opening of Paleo-Tethys in the same area
Mineral chemistry and petrology of highly magnesian ultramafic cumulates from the Sarve-Abad (Sawlava) ophiolites (Kurdistan, NW Iran): New evidence for boninitic magmatism in intra-oceanic fore-arc setting in the Neo-Tethys between Arabia and Iran
No full textThe Sarve-Abad (Sawlava) ophiolitic complex consists of several tectonically dismembered ophiolitic sequences. They are located along the Main Zagros Thrust Zone, which marks the ophiolitic suture between the Arabian and Sanandaj-Sirjan continental blocks. They represent a portion of the southern Neo-Tethyan oceanic lithosphere, which originally existed between the Arabian (to the south) and Eurasian (to the north) continental margins. The Sarve-Abad ophiolites include cumulitic lherzolites bearing minor dunite and chromitite lenses in places. The main rock-forming minerals in ultramafic cumulates are cumulus olivine and inter-cumulus clinopyroxene and orthopyroxene. Minor (<5%) chromian spinel occurs as both cumulus and inter-cumulus phases.Cr#, Mg# and TiO2, Cr2O3, and Al2O3 concentrations of chromian spinel from ultramafic cumulates and chromitites plot in the forearc and boninite spinel fields, respectively. Clinopyroxene has very high Mg# and low TiO2 contents. Calculated TiO2 and Al2O3 compositions and Mg# in the parental melt that was in equilibrium with chromian spinel and olivine are consistent with supra-subduction zone-type compositions. Whole-rock geochemistry of the ultramafic cumulates is characterized by very low incompatible element content and a general enrichment in Th with respect to Ta and Nb. Chondrite-normalized REE patterns show different trends with either (La/Sm)N<1 and (Sm/Yb)N<1 or (La/Sm)N1 and (Sm/Yb)N<1 (U-shaped pattern). Both these patterns are compatible with boninitic-type parental melts. Accordingly, petrogenetic modeling using REE composition indicates that Sarve-Abad ultramafic cumulates may have formed by small degrees (5-15%) of fractional crystallization from typical boninitic melts characterized by either light REE/medium REE depletion or enrichment. Mineral chemistry and whole-rock chemistry clearly indicate that the Sarve-Abad ultramafic cumulates and chromitites record an episode of boninitic magmatism that occurred within the southern Neo-Tethys Ocean during the Late Cretaceous. Boninitic melts in the Sarve-Abad ophiolites were formed by partial melting of depleted peridotite which made up the residual mantle after MORB-type melt extraction. This was subsequently enriched with light REE and large ion lithophile elements by subduction-derived fluids. It is therefore suggested that this boninitic magmatism was generated in the forearc sector of a short-lived intra-oceanic arc that was located southward with respect to the "Andean-type" subduction below the Sanandaj-Sirjan continental margin
Pesteh-Set
No full textPesteh-Set, A Pistachio Dataset containing 6 videos and 423 labeled images.For more details refer to: https://github.com/mr7495/Pesteh-SetIf you find this dataset useful, cite it by:@misc{rahimzadeh2020introduction, title={Introduction of a new Dataset and Method for Detecting and Counting the Pistachios based on Deep Learning}, author={Mohammad Rahimzadeh and Abolfazl Attar}, year={2020}, eprint={2005.03990}, archivePrefix={arXiv}, primaryClass={cs.CV}}THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
Pesteh-Set
No full textPesteh-Set, A Pistachio Dataset containing 6 videos and 423 labeled images.For more details refer to https://github.com/mr7495/Pesteh-SetCodes description is available at https://github.com/mr7495/Pistachio-Counting.If you find this dataset useful, cite it by:@misc{rahimzadeh2020introduction, title={Introduction of a new Dataset and Method for Detecting and Counting the Pistachios based on Deep Learning}, author={Mohammad Rahimzadeh and Abolfazl Attar}, year={2020}, eprint={2005.03990}, archivePrefix={arXiv}, primaryClass={cs.CV}}THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
Pesteh-Set
No full textPesteh-Set, A Pistachio Dataset containing 6 videos and 423 labeled images.For more details refer to https://github.com/mr7495/Pesteh-SetCodes description is available at https://github.com/mr7495/Pistachio-Counting.If you find this dataset useful, cite it by:@misc{rahimzadeh2020introduction, title={Introduction of a new Dataset and Method for Detecting and Counting the Pistachios based on Deep Learning}, author={Mohammad Rahimzadeh and Abolfazl Attar}, year={2020}, eprint={2005.03990}, archivePrefix={arXiv}, primaryClass={cs.CV}}THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
A showcase of igneous processes in the Urumieh-Dokhtar Magmatic Arc: the Miocene-Quaternary collisional magmatism of the Bijar-Qorveh area, northwest Iran
No full textThe Cenozoic Arabia-Iran continental collision was associated with emplacement of a large variety of magmatic rock types. This aspect is particularly evident in the Bijar-Qorveh area of NW Iran, where Miocene andesitic to rhyolitic rocks and Quaternary basic alkaline rocks crop out. The Miocene intermediate to acid compositions show radiogenic Sr and Pb isotopic compositions (87Sr/86Sri 0.70531-0.71109, 206Pb/204Pb 18.71-19.01, 207Pb/204Pb 15.66-15.73, 208Pb/204Pb 38.76-39.14), coupled with unradiogenic Nd isotopic ratios (143Nd/144Ndi 0.51223-0.51265). These characteristics, together with primitive mantle-normalized multielemental patterns resembling “subduction-related” geochemical fingerprints, are considered ultimately derived from the Iranian plate mantle wedge, metasomatised during previous NE-directed Neothetyan Ocean subduction. The alkali-rich andesitic and dacitic rocks evidence both closed- and open-system differentiation, as typically observed for collisional settings in general. Both rock types display a high Sr/Y (37-100) and La/Yb (29-74) “adakitic” signature that it is interpreted here with plagioclase (± amphibole) accumulation or melting of local mafic crustal rocks. Open-system processes involve recycling of crustal cumulates for pyroxene-rich andesite and biotite-rich dacite varieties, and low-degree partial melting of the local crust for leuco-rhyolites.
A radical change occurred during the Quaternary, when SiO2-understaturated to SiO2-saturated poorly evolved rocks (basanites, tephrites, alkaline and subalkaline basalts) were emplaced. The complete change of mantle sources suggests a phase of local extensional tectonics related with WNW-ESE right-transcurrent faults. The major oxide, as well as incompatible trace element and Sr-Nd-Pb isotopic fingerprint of these younger rocks is more akin to that of intraplate magmas, but still bearing some evidences for a variable contribution from a “subduction-modified” mantle source. The NW-trend of increasing involvement of this subduction component, is indicative of the strong tectonic control on magmatism. Additional lithotypes indicate the presence of open-system differentiation and remelting processes in the youngest phase of magmatic activity
Quaternary melanephelinites and melilitites from Nowbaran (NW Urumieh-Dokhtar Magmatic Arc, Iran): origin of ultrabasic-ultracalcic melts in a post-collisional setting
No full textThe small Quaternary volcanic district of Nowbaran (NW Iran) belongs to the Urumieh-Dokhtar Magmatic Arc, a ~1800 km long NW-SE striking Cenozoic belt characterized by the irregular but abundant presence of subduction-related igneous products. Nowbaran rocks are characterized by absence of feldspars coupled with abundance of clinopyroxene and olivine plus nepheline, melilite and other rarer phases. All the rocks show extremely low SiO2 (35.4-41.4 wt%), very high CaO (13.1-18.3 wt%) and low Al2O3 (8.6-11.6 wt%), leading to ultracalcic compositions (i.e., CaO/Al2O3 >1). Other less peculiar, but still noteworthy, characteristics are the high MgO (8.7-13.3 wt%) and Mg# (0.70-0.75), coupled with a variable alkali content with sodic affinity (Na2O = 1.8-5.4 wt%; K2O = 0.2-2.3 wt%) and variably high LOI (1.9-10.4 wt%; average 4.4 wt%). Measured isotopic ratios (87Sr/86Sr = 0.7052-0.7056; 143Nd/144Nd = 0.51263-0.51266; 206Pb/204Pb = 18.54-18.66; 207Pb/204Pb = 15.66-15.68; 208Pb/204Pb = 38.66-38.79) show small variations and plot within the literature field for the Cenozoic volcanic rocks of western Iran but tend to be displaced towards slightly higher 207Pb/204Pb. Primitive mantle-normalized multielemental patterns are intermediate between typical subduction-related melts and nephelinitic/melilititic melts emplaced in intraplate tectonic settings. The enrichment in Th, coupled with high Ba/Nb and La/Nb, troughs at Ti in primitive mantle-normalised patterns, radiogenic 87Sr/86Sr and positive 7/4 anomalies (from +15.2 to +17.0) are consistent with the presence of (old) recycled crustal lithologies in the sources.The origin of Nowbaran magmas cannot be related to partial melting of C-H-free peridotitic mantle, nor to digestion of limestones and marls by “normal” basaltic melts. Rather, we favour an origin from carbonated lithologies. Carbonated eclogite-derived melts or supercritical fluids, derived from a subducted slab, reacting with peridotite matrix, could have produced peritectic orthopyroxene- and garnet-rich metasomes at the expenses of mantle olivine and clinopyroxene. The residual melt compositions could evolve towards SiO2-undersaturated, CaO- and MgO-rich and Al2O3-poor alkaline melts. During their percolation upwards, these melts can partially freeze reacting chromatographically with portions of the upper mantle wedge, but can also mix with melts from shallower carbonated peridotite. The T-P equilibration estimates for Nowbaran magmas based on recent models on ultrabasic melt compositions are compatible with provenance from the lithosphere-asthenosphere boundary at average temperature (~1200 °C ± 50 °C). Mixing of melts derived from subduction-modified mantle sources with liquids devoid of any subduction imprint, passively upwelling from slab break-off tears could generate magmas with compositions recorded in Nowbaran
Characteristics of patients, by country.
No full text∧<p>Previously unpublished dataset.</p><p>*Contributed by author.</p>#<p>S. Rahimzadeh, F. Farzadfar F, and M. Ghaziani, unpublished data.</p
COVID-19 CT-Scans Dataset
No full textCOVID-CTset: A Large COVID-19 CT Scans dataset containing 63849 images from 377 patients
Some samples of the dataset are uploaded here.
For more details and using the Full dataset refer to https://github.com/mr7495/COVID-CTset
The shared links are available at the GitHub profile.
Please cite this dataset by:
@article {Rahimzadeh2020.06.08.20121541,
author = {Rahimzadeh, Mohammad and Attar, Abolfazl and Sakhaei, Seyed Mohammad},
title = {A Fully Automated Deep Learning-based Network For Detecting COVID-19 from a New And Large Lung CT Scan Dataset},
elocation-id = {2020.06.08.20121541},
year = {2020},
doi = {10.1101/2020.06.08.20121541},
publisher = {Cold Spring Harbor Laboratory Press},
URL = {https://www.medrxiv.org/content/early/2020/06/12/2020.06.08.20121541},
eprint = {https://www.medrxiv.org/content/early/2020/06/12/2020.06.08.20121541.full.pdf},
journal = {medRxiv}
Investigation of Natural Effective Gamma Dose Rates case study: Ardabil Province in Iran
No full textGamma rays pose enough energy to form charged particles and adversely affect human health. Since, the external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined, natural background gamma dose rates and corresponding annual effective doses were determined for selected cities of Ardabil province from 2009 to 2010. Outdoor gamma dose rates were measured using an Ion Chamber Survey Meter in 105 locations in selected districts. Average absorbed dose for Ardabil, Sar-Ein, Germy, Neer, Shourabil Recreational Lake, and Kosar were determined as 265, 219, 344, 233, 352, and 358 nSvh-1, respectively. Although dose rates recorded for Germi and Kosar are comparable with some areas with high natural radiation background, however, the dose rates in other districts are well below the levels reported for such locations. Average annual effective dose due to indoor and outdoor gamma radiation for Ardabil province was estimated to be 1.73 (1.35-2.39) mSv, which is on average 2 times higher than the world population weighted average
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