Hasil untuk "Petrology"

J. Bastías-Silva, J. Bastías-Silva, J. Bastías-Silva et al.

<p>While thermochronological studies have constrained the landscape evolution of several of the crustal blocks of West and East Antarctica, the tectono-thermal evolution of the Ellsworth Mountains remains relatively poorly constrained. These mountains are among the crustal blocks that comprise West Antarctica and exhibit an exceptionally well-preserved Palaeozoic sedimentary sequence. Despite the seminal contribution of Fitzgerald and Stump (1991), who suggested an Early Cretaceous uplift event for the Ellsworth Mountains, further thermochronological studies are required to improve the current understanding of the landscape evolution of this mountain chain. We present new zircon (U–Th) <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="1b4178c77ca0d4bfee6c9ddd864f3a43"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="se-15-555-2024-ie00001.svg" width="8pt" height="14pt" src="se-15-555-2024-ie00001.png"/></svg:svg></span></span> He (ZHe) ages, which provide insights into the landscape evolution of the Ellsworth Mountains. The ZHe ages collected from near the base and the top of the sequence suggest that these rocks underwent burial reheating after deposition. A cooling event is recorded during the Jurassic–Early Cretaceous, which we interpret as representing exhumation in response to rock uplift of the Ellsworth Mountains. Moreover, our results show that while ZHe ages at the base of the sequence are fully reset, towards the top ZHe ages are partially reset. Uplift and exhumation of the Ellsworth Mountains during the Jurassic–Early Cretaceous was contemporaneous with the rotation and translation of this crustal block with respect to East Antarctica and possibly the Antarctic Peninsula. Furthermore, this period is characterized by widespread extension associated with the disassembly and breakup of Gondwana, with the Ellsworth Mountains playing a key role in the opening of the far southern Atlantic. Based on these results, we suggest that uplift of the Ellsworth Mountains during the disassembly of Gondwana provides additional evidence for major rearrangement of the crustal blocks between the South American, African, Australian and Antarctic plates. Finally, uplift of the Ellsworth Mountains commenced during the Jurassic, which predates the Early Cretaceous uplift of the Transantarctic Mountains. We suggest that the rift-related exhumation of the Ellsworth Mountains occurred throughout two events: (i) a Jurassic uplift associated with the disassembly of southwestern Gondwana and (ii) an Early Cretaceous uplift related with the separation between Antarctica and Australia, which is also recorded in the Transantarctic Mountains.</p>

S. Karunarathne, P.L. Dharmapriya, W.M.H.M. Wijesinghe et al.

The Mannar Basin is a rift basin formed during the breakup of Gondwana, comprising sedimentary deposits from multiple cycles. Exploration for hydrocarbons has uncovered igneous sequences distributed throughout the basin's sedimentary sequences. These sequences exhibit geochemical characteristics, typical for flood basalts formed during a series of eruptions from 60 to 62 Ma. Previous studies have focused on the petroleum system, tectonostratigraphy, lithostratigraphy, and the paleo-environmental setting, therefore, little was known about the petrogenesis of this flood basalt sequence. This study investigates the petrogenesis of the flood basalt sequence, focusing on crystallization temperature, source magma characteristics, and the nature of magma fractional crystallization. Additionally, it examines the mineralogical characteristics, including clay minerals, of the interstratified sedimentary layers to interpret their origins—an area that has not been previously studied in depth. Petrographic thin sections were prepared from unwashed drill cuttings taken from a depth of 4000–4200 m in the Barracuda petroleum exploration well. A detailed petrographic study was conducted on these samples to investigate the petrogenesis. Additionally, electron probe microanalysis (EPMA) was performed to determine the mineral chemistry of the basalt and interstratified sedimentary rock samples. The basalts are primarily composed of plagioclase (An62-82) and clinopyroxene (mostly augite), with minor occurrences of orthopyroxene (En54-67) and ulvöspinel. Only the lower-most basalt layers (4200–4210 m) contain olivine (Fo56-71). High-Al orthopyroxenes were observed in the shallower sequence. Mineral zoning and mineral chemical variations record fractional crystallization of the mafic magma. Together, these minerals reflect a complex magmatic evolution, where, initially, high-temperature conditions prevailed, followed by differentiation and fractional crystallization; a transition from primitive to more evolved conditions. Geothermometric calculations indicate crystallization temperatures of the basalt varying from 1330 to 1340 °C, typically associated with mantle-derived magmas and representing high-temperature magmatic processes.The interlayered sedimentary rocks within the basalt sequence are dark-coloured and consist of weathered feldspar and clinopyroxenes, with minor quartz and calcite. Powder x-ray diffraction (XRD) analyses reveal the presence of clay minerals such as smectite, antigorite, attapulgite, and chlorite in these sedimentary rocks. While unpublished reports suggest that the interlayered rocks are sandstones and shales (based on gamma-ray log data), these analyses indicate that they are volcaniclastic sediments resulting from the weathering of individual layers of the flood basalt sequence after their eruption.

Peter G. Velikanov, Yury P. Artyukhin

The design of multi-storey buildings is a natural trend in the development of a modern metropolis. Obtaining exact solutions when studying their own and forced oscillations within the framework of a continuous homogeneous medium model (continuum mechanics) with an infinite number of degrees of freedom is often difficult to implement. Therefore, in the article (as part of the modernization of the finite element method), the model of a multi-storey building is discretized and endowed with a finite number of degrees of freedom placed in the middle of the finite elements at the nodes (the mass of finite elements is also placed there), which elastically interact with the finite elements of the model that do not have mass. It is believed that the elements of a multistorey building work only for bending, which is fully justified by comparing the frequencies of its bending and longitudinal oscillations. The resolving system of differential equations of oscillations of a multi-storey building, in which expressions for energies (potential, kinetic and Rayleigh) are written in quadratures, is obtained using Lagrange equations of the second kind. In the article, the problems of free oscillations of 3- and 100-storey buildings are solved using Green’s functions, stiffness, mass, compliance matrices, etc. The approximate results obtained in the article, when compared with the little-known approximate results obtained by other methods, as well as exact results (direct and indirect methods of boundary elements), showed a good correspondence.

Богомолов Леонид Михайлович, Костылев Дмитрий Викторович, Костылева Наталья Владимировна et al.

Представлены результаты экспериментов по электрозондированию приповерхностного слоя земной коры в разломной зоне с регистрацией сейсмоакустических и сейсмических шумов в ближней зоне у источника (возбуждающего диполя). Эксперименты проведены в 2021–2022 гг. в южной части Центрально-Сахалинского разлома с использованием разработанного в ИМГиГ ДВО РАН источника электрических импульсов, мощностью до 3 кВт. Цель была исследовать сейсмоакустические проявления реакции среды на зондирование импульсами тока силой 5–13 А. Генераторное устройство обеспечивало силу тока в диполе существенно выше ее характерных значений в случае зондирования при электроразведке методами сопротивлений, а также при обычной сейсмоэлектроразведке. При этом диапазон токовых амплитуд был намного меньше, чем в случае глубинных зондирований с использованием геофизических МГД-генераторов или сверхмощных электроимпульсных устройств. До настоящего времени обратный сейсмоэлектрический эффект оставался практически неисследованным при токах в «промежуточном» диапазоне ~10 А и при масштабах порядка нескольких сотен метров. Наличие или отсутствие реакции среды на электрозондирования устанавливалось по записям молекулярно-электронных приборов (производитель ООО «R-sensors», Россия): широкополосного сейсмометра СМЕ-6111 и гидрофона, установленных на расстоянии около 50 м от одного из полюсов возбуждающего электрического диполя. Обнаружено возрастание среднего уровня сейсмоакустического шума при электрозондированиях, что по существу является разновидностью обратного сейсмоэлектрического эффекта II рода (возбуждение упругих волн при прохождении электрического тока в двухфазной среде). Подобное проявление реакции среды в ближней зоне около одного из электродов диполя на пропускание импульсов тока ранее не отмечалось. При этом прирост уровня шума происходит практически без задержек после начала электрозондирований, что находится в соответствии с ранее полученными результатами об откликах сейсмоакустической эмиссии на мощные импульсы тока, которые применялись для глубинных зондирований в Северном Тянь-Шане.

Mohammad Humand, Mohammad Reza Khorsand Movaghar, Mobarakeh Mohammadpour et al.

Abstract A multitude of research works have been conducted in the past decade to better predict the change of critical properties of fluids confined in nanopores, known as critical shift, due to its great impact upon calculations of fluid properties in tight reservoirs. Modeling of this phenomenon commenced with developing equations of state (EOS) and has been continuing with correlations, all based on the two-parameter Lennard–Jones (L–J) potential function. Although these approaches have tried to present passable estimations of critical shift, sufficiently accurate predictions of critical shift are still missing in the literature. In this study, the three-parameter Kihara potential, as a more physically realistic alternative, is used to develop the van der Waal (vdW) EOS, and accordingly, a fluid-dependent expression is derived to calculate the critical temperature of confined fluids, i.e., pore critical temperature ( $${T}_{\mathrm{cp}}$$ T cp ). Using 50 data points of $${T}_{cp}$$ T cp reports for normal alkanes in the literature, the average error of our model is only 2.23%, 6.4% less than that of the L–J model. Furthermore, despite simple correlations of previous works, herein the Kihara parameters are exclusively tuned for each component based on their $${T}_{cp}$$ T cp reports, which resulted in an average error of 0.4% for normal alkanes. Finally, the pressure–volume diagrams of vdW and Peng–Robinson EOSs associated with the Kihara potential function are comprehensively discussed. The findings of this study can help researchers with more accurate predictions of the critical temperature of fluids confined in tight porous media, thereby providing more precise calculations of fluid properties and behavior at equilibrium conditions.

Luca Toffolo, Simone Tumiati, Alberto Villa et al.

Biogenic carbonaceous material (CM) is the main carrier of organic carbon in the subduction zone and contributes to COH fluid production and volcanic arc gaseous emissions. Here we investigated the effect of the structural, textural and chemical heterogeneity of CM on its reactivity and redox dissolution by conducting short-lived (1 h) experiments, where synthetic analogues of CM [ordered graphite, graphite oxide (GO), mesoporous carbon (MC), Vulcan® carbon (VC) and glass-like carbon (GC)], are reacted with water at p = 1GPa and T = 550°C–conditions typical of a warm forearc subduction–and fO2 buffered from ▵FMQ ≈ +4 to −7. We show that the amount of dissolved CM (CMdissolved) and the proportion of volatile carbon species (Cvolatile) in the fluid is related both to the structure and the peculiar surficial properties of the carbon forms, such as carbon sp2-and sp3-hybridization, amount of oxygen heteroatoms, presence of oxygenated functional groups (OFGs) and of active sites. MC and graphite (C(sp2) &gt; 94 at%, O &lt; 1 at%, OFGs &lt; 2.2 at %, high proportion of active sites) are relatively inert (CMdissolved &lt; 0.4 mol%) but the former reacts more extensively at extreme redox conditions (producing CO2 + CO and CO2 + CH4 Cvolatile mixtures at ▵FMQ ≈ +4 and −7, respectively), while the latter has a maximum of Cvolatile production (CO2 + CH4) at ▵FMQ ≈ 0, which is not observed in a 10-day long run; partly-ordered GO (C(sp3) ∼ 92 at%, O ∼31 at%, OFGs ∼41 at%) is the most reactive material at all redox conditions (CMdissolved &lt; 2.6 mol%) and produces CO2 as the dominant Cvolatile species; disordered GC, and VC (C(sp3) &lt; 18 at%, O &lt; 8 at%, OFGs &lt; 30 at%) are more reactive at ▵FMQ ≈ +4 (CMdissolved ∼ 1mol%) and ▵FMQ ≈ −7 (CMdissolved &lt; 1 mol%), where Cvolatile is dominantly CO2 and CH4, respectively. Besides the significant deviations from thermodynamically predicted graphite-saturated COH fluid composition and speciation, our results suggests that: 1) immature CM [disordered, rich in C(sp3), O, OFGs] is preferentially dissolved under high fluid fluxes and may buffer fluids to rather oxidizing conditions; 2) a descending flux of oxygen (and hydrogen) bond to CM may exist.

Santanu Ghosh, Anwita Ojha, Atul Kumar Varma

Abstract The present study focuses on the inorganic geochemical features of the bituminous coal samples from the Raniganj and the Jharia Basins, as well as the anthracite samples from the Himalayan fold-thrust belts of Sikkim, India. The SiO2 content (48.05 wt% to 65.09 wt% and 35.92 wt% to 50.11 wt% in the bituminous and anthracite samples, respectively) and the ratio of Al2O3/TiO2 (6.97 to 17.03 in the bituminous coal samples and 10.34 to 20.07 in the anthracite samples) reveal the intermediate igneous source rock composition of the minerals. The ratio of the K2O/Al2O3 in the ash yield of the bituminous coal samples (0.03 to 0.09) may suggest the presence of kaolinite mixed with montmorillonite, while its range in the ash yield of the anthracite samples (0.16 to 0.27) may imply the presence of illite mixed with kaolinite. The chemical index of alteration values may suggest the moderate to strong chemical weathering of the source rock under sub-humid to humid climatic conditions. The plot of the bituminous coal samples in the A–CN–K diagram depicts the traditional weathering trend of parent rocks, but the anthracite samples plot near the illite field and are a bit offset from the weathering trend. This may imply the plausible influences of the potassium-metasomatism at post coalification stages, which is further supported by high K2O/Na2O ratio (29.88–80.13). The Fourier transform infrared spectra further reveal the hydroxyl stretching intensity of illite in the anthracite samples substantiating the effect of the epigenetic potassium-metasomatism. The decrease in total kaolinite intensity/compound intensity of quartz and feldspar may provide additional evidence towards this epigenetic event.

Thiago Lynyker da Silva Bernardes, Rafael Aquino Amadeu, Rodrigo Sousa Santos et al.

In the present work, the characteristics of the shale rock, collected in the surrounds of Limeira, in the interior of São Paulo, were studied. Shales are mostly fine granules, susceptible to the mineralogical rearrangement, and their chemical composition is quite varied due to the geomorphology and the tectonism undergone by the sedimentary basins. They are impermeable structures, formed by the consolidation of layered clay with thin laminations. Because of these characteristics presented, together with the decline of petroleum production, a growing interest in a better understanding and knowledge of the physical-chemical properties of the shale rocks inner is observed.  In this work, the gamma-ray computed industrial tomography technique was established to be used in the characterization of the shale samples. The results were validated using those obtained by conventional methodologies, such as scanning electron microscopy (SEM), x-ray fluorescence and x-ray diffraction. Several characteristics have been studied, such as the analysis of the particle morphology, the contrasts and distributions of these particles in the internal structure of the rock, identification of the types of elements present (quantitative analysis), as well as establishing the proportion of each element present in the mineral through its crystalline structure, with images of the rock internal structure.

José Nespereira, José Antonio Blanco, Mercedes Suárez et al.

The Dueñas Clay Formation is considered an example of a deposit of lacustrine continental origin. It is formed mainly by overconsolidated clays and includes feldspathic arenites, and clayey and silty levels; however, in geotechnical projects it is considered a clay unit and treated as a whole. The structure of each level was assessed in the field, in thin sections, and by SEM in the case of the clayey level. In addition, identification, strength, deformation, and durability tests were undertaken according to the nature of the samples (grain size analysis, Atterberg Limits, point load test, direct shear tests, uniaxial compression tests, swelling pressure, and unidimensional consolidation tests). The durability test was used as a criterion for dividing the levels within the formation according to their behavior as soil or rock. It was observed that the proportion and type of carbonate cementation controls the way in which the material behaves, with sparithic cement increasing the strength. The clay levels are expansive due to the presence of smectite, which also influences their behavior under shear stress. In addition, the massive and laminar structure of the layers caused by the continental conditions, in addition to the processes of post-sedimentation, explain their low compressibility.

Bing Zhang, Khafiz Muradov, Akindolu Dada

Abstract Oil and gas production wells are often equipped with modern, permanent or temporary in-well monitoring systems, either electronic or fiber-optic, typically for measurement of downhole pressure and temperature. Consequently, novel methods of pressure and temperature transient analysis (PTTA) have emerged in the past two decades, able to interpret subtle thermodynamic effects. Such analysis demands high-quality data. High-level reduction in data noise is often needed in order to ensure sufficient reliability of the PTTA. This paper considers the case of a state-of-the-art intelligent well equipped with fiber-optic, high-precision, permanent downhole gauges. This is followed by screening, development, verification and application of data denoising methods that can overcome the limitation of the existing noise reduction methods. Firstly, the specific types of noise contained in the original data are analyzed by wavelet transform, and the corresponding denoising methods are selected on the basis of the wavelet analysis. Then, the wavelet threshold denoising method is used for the data with white noise and white Gaussian noise, while a data smoothing method is used for the data with impulse noise. The paper further proposes a comprehensive evaluation index as a useful denoising success metrics for optimal selection of the optimal combination of the noise reduction methods. This metrics comprises a weighted combination of the signal-to-noise ratio and smoothness value where the principal component analysis was used to determine the weights. Thus the workflow proposed here can be comprehensively defined solely by the data via its processing and analysis. Finally, the effectiveness of the optimal selection methods is confirmed by the robustness of the PTTA results derived from the de-noised measurements from the above-mentioned oil wells.

S. M. Talha Qadri, Md Aminul Islam, Mohamed Ragab Shalaby et al.

Abstract The study used the sedimentological and well log-based petrophysical analysis to evaluate the Farewell sandstone, the reservoir formation within the Kupe South Field. The sedimentological analysis was based on the data sets from Kupe South-1 to 5 wells, comprising the grain size, permeability, porosity, the total cement concentrations, and imprints of diagenetic processes on the reservoir formation. Moreover, well log analysis was carried on the four wells namely Kupe South 1, 2, 5 and 7 wells for evaluating the parameters e.g., shale volume, total and effective porosity, water wetness and hydrocarbon saturation, which influence the reservoir quality. The results from the sedimentological analysis demonstrated that the Farewell sandstone is compositionally varying from feldspathic arenite to lithic arenite. The analysis also showed the presence of significant total porosity and permeability fluctuating between 10.2 and 26.2% and 0.43–1376 mD, respectively. The diagenetic processes revealed the presence of authigenic clay and carbonate obstructing the pore spaces along with the occurrence of well-connected secondary and hybrid pores which eventually improved the reservoir quality of the Farewell sandstone. The well log analysis showed the presence of low shale volume between 10.9 and 29%, very good total and effective porosity values ranging from 19 to 32.3% as well as from 17 to 27%, respectively. The water saturation ranged from 22.3 to 44.9% and a significant hydrocarbon saturation fluctuating from 55.1 to 77.7% was also observed. The well log analysis also indicated the existence of nine hydrocarbon-bearing zones. The integrated findings from sedimentological and well log analyses verified the Farewell sandstone as a good reservoir formation.

N. I. Bryanchaninova, A. M. Askhabov

October 14, 2019 there is the 100th Anniversary of Mark V. Fishman – one of the most famous person of the Instituteof Geology of Komi Science Centre UB RAS and organizers of fundamental explorations in Komi Republic, professor,well–known scientist in regional geology and petrology. His name symbolizes an entire era in history of geological research in Komi Republic and on the North–East of European part of Russia. About twenty five years M.V. Fishman wasdirector of the Institute of Geology and did a lot as a scientist and an organizer of the geologic research.

Alireza Zarasvandi, Mohsen Rezaei, Majid Tashi et al.

Introduction The formation of the Zagros orogenic belt is attributed to northeastward oblique subduction of the Neotethys beneath the western border of central Iran. This was followed by continental collision between the Afro-Arabian plate and the central Iran microcontinet (Zarasvandi et al., 2015). The Zagros orogen is characterized by three main parallel structural zones consisting of Zagros fold and thrust belt, the Sanandaj–Sirjan metamorphic zone, and the Urumieh–Dokhtar magmatic arc (Mohajjel et al., 2003). The Urumieh–Dokhtar magmatic arc is dominated by the widespread occurrence of Eocene to Quaternary intrusive and extrusive rocks. It is considered as being one of the main Cu bearing regions in the world, where world class giant porphyry deposits, as well as large and small sub-economic porphyry Cu ± Mo ± Au systems have been reported and investigated by many authors (Shafiei et al., 2009; Zarasvandi et al., 2005). In addition to UDMA, the Sanandaj-Sirjan zone (SSZ) hosts several Jurassic-Cretaceous intrusive complexes extending from the northwest to southeast SSZ. It should be noted that these granitoids are barren and porphyry mineralization has not been accompanied with these intrusions. This paper tried to compare the available geochemical data of productive granitoids in the Urumieh-Dokhtar (i.e., Dalli, Ali-Abad and Darreh-Zerreshk, Parkam, Sarcheshmeh, Meiduk and Sungun), and those of barren intrusions in the Sanandaj-Sirjan zone (i.e., Aligodarz, Bourujerd, Alvand, Astaneh, Hasan Robat, and Siah Koh). Materials and methods This investigation is based on the available geochemical data on the six barren intrusions in the SSZ (i.e., Aligodarz, Bourujerd, Alvand, Astaneh, Hasan Robat and Siah Kohe), and productive intrusive rocks (porphyry associated intrusions) in the UDMA (i.e., Dalli, Ali-Abad and Darreh-Zerreshk, Parkam, Sarcheshmeh, Meiduk and Sungun). Data for the UDMA porphyry intrusions (41 samples) were adopted from studies of Daneshjou (2014), Zarasvandi et al. (2005), Taghipour and Mohammadi Laghab (2014), Barzegar (2007), Taghipour (2007), and Hezarkhani (2006). Furthermore, the data of the SSZ barren intrusions (42 samples) comes from Esna Ashari et al. (2012), Khalaji et al. (2007), Aliani et al. (2012), Tahmasbi et al. (2010), Alirezaei and Hassanzadeh (2001), and Arvin et al. (2007). Two criteria were used for selection of 83 representative samples: (1) samples with a relatively similar mineralogical and compositional range (quartz diorite, quartz monzonite, granodiorite and granite), and (2) samples with the least amount of alteration (minimal amounts of Loss On Ignition; LOI wt.% = H2O + CO2). Results Productive intrusions in UDMA have positive Eu anomalies, LREE enrichment relative to HREE, and high Lan/Ybn ،Sr/Y، Dyn/Ybn، Lan/Smn ratios. In comparison, barren granitoids in the SSZ are characterized by steep downward LREE to HREE, negative Eu anomalies and low Lan/Ybn ، Sr/Y، Dyn/Ybn، Lan/Smn ratios. Discussion Based on the presented results, it is proved that due to the lack of considerable crustal thickness in SSZ (during the subduction of the Neotethyan oceanic lithosphere under the SSZ zone), and the presence of dry magma (low H2O contents), the SSZ granitoids exhibit barren characteristics. In contrast, during the ongoing processes of closure of Neo-Tethys and during compression and crustal shortening, magma mixing and evolution toward high magmatic water content lead to the increasing of metal endowment in the porphyry associated granitoids of (UDMA) It seems that magma generation from the melting of thickened lower crust (garnet amphibolite source) could be considered as one important key factors for the generation of metal-rich magmas with high oxidation state and high H2O contents has led to the development of porphyry Cu systems in the UDMA compared to those of SSZ granitoids. Acknowledgements The authors are grateful to the Shahid Chamran University of Ahvaz for the research funding by the Grant Commission in 2017. References Aliani, F., Maanijou, M., Sabouri, Z. and Sepahi, A.A., 2012. Petrology, geochemistry and geotectonic environment of the Alvand Intrusive Complex, Hamedan, Iran. Chemie der Erde-Geochemistry, 72(4): 363–383. Alirezaei, S. and Hassanzadeh, J., 2012. Geochemistry and zircon geochronology of the Permian A-type Hasanrobat granite, Sanandaj–Sirjan belt: A new record of the Gondwana break-up in Iran. Lithos, 15(151): 122–134. Arvin, M., Pan, Y.M., Dargahi, S., Malekizadeh, A. and Babaei, A., 2007. Petrochemistry of the Siah-Kuh granitoid stock southwest of Kerman, Iran: implications for initiation of neotethys subduction. Journal of Asian Earth Sciences, 30(3): 474–489. Barzegar, H., 2007. Geology, petrology and geochemical characteristics of alteration zones within the Seridune prospect, Kerman, Iran. Ph.D. thesis, Aachen University, Aachen, Germany, 320 pp. Daneshjou, M., 2014. Investigation of geology, geochemistry and genetic model of the Dalli porphyry Cu–Au deposit, Delijan, Markazi province. M.Sc. Thesis, Shahid Chamran University, Ahvaz, Iran, 150 pp. (in Persian with English abstract) Esna-Ashari, A., Tiepolo, M., Valizadeh, M.V., Hassanzadeh, J. and Sepahi, A.A., 2012. Geochemistry and zircon U–Pb geochronology of Aligoodarz granitoid complex, Sanandaj-Sirjan zone, Iran. Journal of Asian Earth Sciences, 43(1): 11–22. Hezarkhani, A., 2006. Petrology of the intrusive rocks within the Sungun porphyry copper deposit, Azerbaijan, Iran. Journal of Asian Earth Sciences, 27(3): 326–340. Khalaji, A.A., Esmaeily, D., Valizadeh, M.V. and Rahimpour-Bonab, H., 2007. Petrology and geochemistry of the granitoid complex of Boroujerd, Sanandaj-Sirjan Zone, Western Iran. Journal of Asian Earth Sciences, 29(5): 859–877. Mohajjel, M., Fergusson, C.L. and Sahandi, M.R., 2003. Cretaceous–Tertiary convergence and continental collision, Sanandaj–Sirjan zone, western Iran. Journal of Asian Earth Sciences, 21(4): 397–412. Shafiei, B., Haschke, M. and Shahabpour, J., 2009. Recycling of orogenic arc crust triggers porphyry Cu mineralization in Kerman Cenozoic arc rocks, southeastern Iran. Mineralium Deposita, 44(3): 265–283. Taghipour, N., 2007. The application of fluid inclusions and isotope geochemistry as guides for exploration, alteration and mineralization at the Meiduk porphyry copper deposit, Shahr-Babak, Kerman. Unpublished Ph.D. thesis, Shahid Bahonar University, Kerman, Iran, 321 pp. Taghipour, N. and Mohammadi Laghab, H., 2014. Sara (Parkam) Porphyry Copper Deposit in Kerman, Iran: Petrography, Geochemistry and Geodynamic Setting. Geochemistry Journal, 1(3): 14–26. Tahmasbi, Z., Castro, A., Khalili, M., Khalaji, A.A. and de la Rosa, J., 2010. Petrologic and geochemical constraints on the origin of Astaneh pluton, Zagros orogenic belt, Iran. Journal of Asian Earth Sciences, 39(3): 81–96. Zarasvandi, A., Liaghat, S. and Zentilli, M., 2005. Geology of the Darreh-Zerreshk and Ali-Abad porphyry copper deposits, central Iran. International Geology Review, 47(6): 620–646.

Afshin Davarpanah, Behnam Mirshekari, Taraneh Jafari Behbahani et al.

Abstract Appropriate estimation of permeability is considered as one of the significant concerns of petroleum industries. Due to the growing demand for hydrocarbon fossil fuels in numerous industries, Petroleum Engineers always try to provide holistic and sustainable solutions to measure this parameter more accurately and to calculate the proper original oil in place (OOIP) and initial reserve. Hence, this accuracy estimation helps engineers whether the production and exploration operations are profitable or not and it might virtually eliminate the unnecessary expenditures. The term production logging tools (henceforth; PLT) involve a wide variety of measurement tools and many sensors. It, too, carries interpretation tools which evaluate the formation properties, in respect of the way PLTs would analyze the formation fluid movements inside and outside of the wellbore and subsequently estimate the production flow rate for each layer. On the other hand, it gives production and completion engineers the chance to investigate the appropriate efficiency of production and perforation processes to organize the remediation methodologies or preplan proper designing for modifying completion procedures which have based on the production logging tools interpretation. The purpose of this comprehensive research is to compare two different techniques (PLT and core analysis) of permeability measurement in a six-layered fractured reservoir and subsequently normalize each parameter to obtain the proper estimation. As a result, according to the evaluation of each technique, the amount of permeability in the layers 1, 2, 3, and 5 is relatively close to each other. Furthermore, regarding higher expenses of core analysis tests and the reliability of PLTs according to the results of this paper in the four out of six individual layers, Emeraude software by utilizing PLT interpretation could be a substitution and preferable methodology instead of core analysis measurements.

mohsen moayyed, robab hajialioghli

The Alamdar rhyolite has been cropped out at the highest top of Mishow Mountain Ranges (i.e. Alamdar top), east of Tasouj. Considering that the rhyolite has been intruded the Kahar Formation, its Precambrian age is more probable. The constituent minerals are quartz, K-feldspar and rare plagioclase characterizing by crystalline to hyalo-crystalline, microlitic porphyric, perthitic, hyalo porphyric and flow textures. Magmatic series of the rocks are high K calc-alkaline and shoshonite. In the view of Al-index, they are peraluminous. The investigated rocks have been classified as A-type (A2 subgroup) granitoids. REE diagrams show high enrichment of LREE relative to HREE and MREE. Spider diagrams have positive anamolies of K, Nd, Rb and negative anomalies of Ta, Nb, and Ti indicating their likely crustal source generation. On the basis of discrimination diagrams they are formed related to Post-COLG tectonic setting. Extensional regimes following to  continental collision between Northern lands with Gondwanian terrains during Ediacaran has been caused decompression melting of continental crust and the Alamdar rhyolite has been originated at the Mishow collisional zone.

Rui Zhang, Xiaoying Xu, Bing Cao et al.

Abstract The pyromellitic dianhydride (PMDA) crosslinked poly(vinyl alcohol) (PVA) was coated on top of the PAN ultrafiltration membrane to form a PVA/PAN composite PV membranes for wastewater desalination. The composite membranes have high application value in industrial wastewater treatment. By varying the membrane fabrication parameters including the weight percent (wt%) of the PMDA, the crosslink temperature and duration, membrane with the best desalination performance was obtained. The composite membrane with a 2-μm-thick PVA selective layer containing 20 wt% of PMDA and being crosslinked at 100 °C for 2 h showed the highest NaCl rejection of 99.98% with a water flux of 32.26 L/(m2 h) at 70 °C using the 35,000 ppm NaCl aqueous solution as feed. FTIR spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis and scanning electron microscope have been used to characterize the structures and properties of both the crosslinked PVA dense films and PVA/PAN composite membranes. The effects of the concentrations of PMDA, the crosslinking time and temperature to the membrane water contact angle, swelling degree, salt rejection and water flux were systematically studied.

Omid Yazdanpanah, Ali Akbar Hassannezhad

Introduction Dehnow-Abid area is a part of the geological map of Eshghabad with scale 1:100000 (Aghanabati, 1994) that is located about 20 kilometers northeast of Eshghabad and in the coordinates of 57° 6´ 0" to 57° 10´ 0" eastern longitude and 34° 28´ 0" to 34 21´ 0" northern latitude. The Dehnow-Abid area is located in Tabas block and east of central Iran structural zone. The small continent east central Iran (Takin, 1972) includes blocks: Loot, Tabas and Yazd that constitute Iran's eastern part (Davoudzadeh and Schmidt, 1982). In geology, we can acquire more information about temperature forming minerals and rocks, pressure, density of the fluid and the chemical composition of the ore bearing fluids by fluid inclusions studies. Properties as well as their role in our understanding of the sources and evolution of ore bearing hydrothermal fluids and genesis of mineral deposits are very important (Rodder, 1979). In this study, we tried to use both field and laboratory studies, including petrography and thermometry studies of fluid inclusions, environment formation of quartz in the specified Dehno-Abid. Materials and methods At first, in order to identify the area, the 1:100000 map of Eshghabad was used. Then, for a complete cognition of mentioned area, after a few field visits and sampling of outcrops of quartz, we prepared 16 double polishing sections from some crystalline and milky quartz. Then, 10 thin sections of sandstones of that area were prepared for identification the host rock. Microscopic examinations on fluid inclusions were done by a LEICA DMLSP polarizing light microscope. Fluid inclusion micro-thermometry studies were done by using a Linkam THM S600 heating and freezing stage and with a TMS94 controller. Also, a cooling LNP which is mounted on an Olympus BX-41 microscope in Laboratory Fluid inclusion of Earth Sciences, Damghan University was used. Discussion and results Lithology of the Dehnow-Abid area included dark shale, fine and coarse grains arkosic and lithic arkose sandstones (Tucker, 1994) that show low grade metamorphic texture which may be attributed to these sediments metamorphosed Jurassic age, but their equivalence is more with Shemshak forrnation (Aghanabati, 1994). Silica mineralization occurred as veins, veinlets and in some parts show silica mass of lense. In this area, there are two generations of faults with trends of northeast-southwest and north-south. Based on the geological section, the North – South faults is the second generation that cut system North-East to South-West faults (Kosari, 2004). In microscopic studies of fluid inclusions different characteristics such as their relationship with the host mineral, phase contents, size, shape, necking down and degree of filling were investigated. Microscopic investigates at room temperature, based on the criteria provided by Van den Kerkhof and Hein, 2001; Shepherd et al., 1985; Rodder, 1984 were performed. These studies indicated that as genetically point fluid inclusions in quartz area are able to divide into three groups (primary, secondary and pseudo secondary). The shapes of fluid inclusions are very different, but partly follow mineral crystallization system. Size of fluid inclusion varies between 5 to 120 microns, but most abundant fluid inclusions have size of 20 to 60 microns. According to a survey done on double polishing sections in laboratory conditions, the phase contents of fluid inclusions may be divided into six groups that include : monophase liquid (L), monophase vapor (V), two phases rich of liquid (L+V), two phases rich of vapor (V+L), three phases (L+V+S) and immiscible liquid (L1+L2+V). The presence of CO2 around gas bubbles can represent metamorphism environments (Yardley and Bodnar, 2014; Van den Kerkhof et al., 2014). Heating analysis was done on 113 samples of fluid inclusions studied in order to investigate the situation homogenization temperature, and cooling analysis was done on 99 selected samples. In addition, 38 samples were tested as heating in order to obtain a homogenization temperature of CO2 phase fluid inclusions (L1+L2+V). Micro-thermometric fluid inclusion investigates shows that the homogenization temperature of the CO2 is varied between 26.1 to 30.6. Fluid inclusion micro-thermometry studies on mineral quartz shows that the homogenization temperature is varied between 247 to 336 ° C, salinty is varied between 0.9 to 15.8 % NaCl eq and mineralizing fluid density range is between 0.7 to 0.9 gr/cm3. Based on evidences from field and laboratory studies, especially microthermometry studies and also the presence of carbonic phase in fluid inclusions, probably silica in the Dehnow-Abid region was formed under metamorphism conditions. On the basis of Wilkinson diagram (Wilkinson, 2001), regional data have been plotted in low temperature range and gold veins that shows metamorphic environments partly. Also plotting these data on a Kessler diagram (Kesler, 2005) suggests a metamorphic source for fluids which have made the veins, lenses and quartz mass of studied area. References Aghanabati, A., 1994. Geological map of Eshghabad, scale 1:100000. Geological Survey of Iran. Davoudzadeh, M. and Schmidt, K., 1982. ZurTrias des Iran. Geologische Rundschau, 71(3): 1021-1039. Kesler, S.E., 2005. Ore Forming Fluid. Element, 1(1): 13-18. Kosari, S., 2004. Systematic geochemical exploration in sheet 1: 100000 Eshghabad. Geological Survey of Iran, Tehran, 135 pp. (in Persian) Rodder, E., 1979. Fluid inclusions as samples of ore fluids. In: H.L. Barnes (Editors), Geochemistry of Hydrothermal Ore Deposite. John Wiley and Sons Interscience, New York, pp.684-737. Rodder, E., 1984. Fluid inclusion. Mineralogical Society of America, V.12, 644 pp. Shepherd, T., Rankin, A.H. and Allderton, D.H.M., 1985. A Practical Guide to Fluid Inclusion Studies Blackie. USA Chapman and Hall, New York, 239 pp. Takin, M., 1972. Iranian Geology and Continental Drift in the Middle East. Nature Cell Biology, 235 (5334): 147-150. Tucker, M.E., (translated by Harami, R.M. and Mahboobi, A.), 1994. Sedimentary Petrology (an introduction to the origion of sedimentary rocks), Jahad Daneshgahi Press, Mashhad, 493 pp. (in Persian) Van den Kerkhof, A. and Hein, U.F., 2001. Fluid inclusion petrography. Lithos, 55(1-4): 27–47. Van den Kerkhof, A., Kronz, A. and Simon, K., 2014. Deciphering fluid inclusions in high-grade rocks. Geoscience Frontiers, 5(5): 683-695. Wilkinson, J.J., 2001. fluid inclusion in hydrothermal ore deposits. Lithos, 55(1-4): 229-272. Yardley, B.W.D. and Bodnar, R.J., 2014. Fluids in the Continental Crust. Geochemical Perspectives, 3(1): 1-127.

Valery Gulyayev, Natalya Shlyun

Abstract Enhancement of technology and techniques for drilling deep directed oil and gas bore hole is one of the most important problems of the current petroleum industry. Not infrequently, the drilling of these bore holes is attended by occurrence of extraordinary situations associated with technical accidents. Among these is the Eulerian loss of stability of a drill string in the channel of a curvilinear bore hole. Methods of computer simulation should play a dominant role in prediction of these states. In this paper, a new statement of the problem of critical buckling of the drill strings in 3D curvilinear bore holes is proposed. It is based on combined use of the theory of curvilinear elastic rods, Eulerian theory of stability, theory of channel surfaces, and methods of classical mechanics of systems with nonlinear constraints. It is noted that the stated problem is singularly perturbed and its solutions have the shapes of localized harmonic wavelets. The calculation results showed that the friction effects lead to essential redistribution of internal axial forces, as well as changing the eigenmode shapes and sites of their localization. These features make the buckling phenomena less predictable and raise the role of computer simulation of these effects.

Nenad Buzjak

Na hrvaškem krasu je veliko udornic. So tudi take, nastale zaradi posedanja (subsidence). Analiziranih je nekaj geomorfoloških elementov in oblik, nastalih z udiranjem in posedanjem (vpliv geoloških okoliščin in stopnje jamskega razvoja na procese udiranja in posedanja, morfologija udornih in subsidenčnih vrtač ter jamskih rovov pod njimi), iz dveh jam z različnih delov hrvaškega krasa (Dolačina mama iz Žumberka in Jama na Sredi s Cresa). Opazovanja potrjujejo, da je podiranje pomembna sestavina v razvoju jam in da je nastajanje udornih in subsidenčnih vrtač pomemben pokazatelj razvojne stopnje krasa. In the Croatian Karst area there are a lot of collapse dolines. Here we can also find structures that are the result of subsidence (subsidence dolines). In the cases of two selected caves in different parts of the Croatian Karst area (Dolačina mama cave - Žumberak Mt. and Jama na Sredi cave - Cres island) some geomorphological elements and features of collapse and subsidence processes were analysed (the influence of geological conditions and the cave’s stage of development to wards collapse/subsidence the morphology of collapse and subsidence dolines and the cave passages beneath them). Observations confirm that collapse is a significant component of cave development and that formation of collapse and subsidence dolines is an important indicator of karst evolution.

V. A. Trunilina, S. P. Roev, A. I. Zaitsev

This article presents the results of detailed study of geologic structure and composition of Munilkan massif of the Main batholith belt of Verkhoyansk-Kolyma mesozoides (Tas-Khayakhtakh Ridge). Granites include numerous xenoblocks of gabbro, dolerites and subvolcanic granites they are intruded by fissure bodies and dikes of leucogranites-alaskites and trachybasalts-trachydolerites and have neutral ratio with gabbro-diorites, diorites and monzonites, which were formed during interaction of basite and granite magma. Igneous activity occurred at some stages, from Oxfordian to the end of the Early Cretaceous (157-119 Ma). Composition parameters of magmatic rocks correspond to formation of early derivatives in island-arc conditions, late derivatives - in post-collisional and intraplate conditions, that is covers the entire cycle of geologic development of Verkhoyansk-Kolyma mesozoides.