Geological Reports Research Articles

Design Study of Steel Fibre Reinforced Concrete Shaft Lining for Swelling Ground in Toronto, Canada

Reinforced concrete (RC) is a widely used construction material around the world. RC has many advantages in terms of structural stability. However, the reinforcement of RC requires extensive labour costs. Steel fibre reinforced concrete (SFRC) has been widely studied to replace steel bars in concrete structures over the decades. However, most underground structures, such as tunnel lining, are usually designed using conventional RC for long-term stability due to unexpected geotechnical characteristics, such as directional and depth-dependent varied lateral pressure, earthquakes, groundwater, and time-dependent swelling behaviour. In this paper, an alternative design of shaft structure using SFRC, based on the original RC designed data in the Toronto region, was studied to evaluate the feasibility of SFRC replacing conventional RC. A key geological feature of the site is that the bedrock is comprised of Georgian Bay shale, which exhibits long-term time-dependent deformation (TDD). The capacities of RC and SFRC for the shaft lining were calculated based on the Canadian concrete design codes CSA A23.3 and RILEM TC 162-TDF, to assess the benefit of adding steel fibre, and several analytical solutions were used to calculate the applied load on the lining. A specialised TDD constitutive model in Fast Lagrangian Analysis of Continua (FLAC) 2D was developed to estimate whether the optimum installation time of the shaft lining, based on the geological reports, is appropriate under swelling behaviour, and evaluate the resultant long-term stability. The calculated hoop thrust and bending moment for several loading cases were within the capacity of the SFRC shaft lining. The numerical analysis demonstrated that the proposed lining installation time could be reduced, despite consideration of the long-term TDD behaviour.

Application of fuzzy analytic hierarchy process in sandstone aquifer water yield property evaluation

Accurate evaluation of water yield property is the foundation of mine water inrush risk analysis, and is also an important prerequisite for engineering measures selection. There are many factors or parameters that influence the ability of sandstone aquifers to store and transmit water. Furthermore, the degree to which these parameters affect aquifer productivity is variable depending on the spatial distribution of the parameter in question and other hydrogeological parameters that contribute to water yield property When locates in different position of space, or under different hydrogeological condition, influencing degree from the same factor is different. Five hydrogeological parameters were selected and analyzed to rank areas for potential mine inflow risk based on the hydrogeological units to be intersected by the Yongan Coal Mine. The parameters used in the analysis include aquifer thickness, aquifer lithological association, development of fractures, drilling flushing fluid consumption rates and the coefficient of permeability. Firstly, the distribution of each single factor was separately analyzed, parameters were standardized using the standardization range transform method. In this way, dimension and value range difference could be eliminated, and transformation rule of information data could be studied under the same standard scale. The weight of each factor was determined using improved fuzzy analytic hierarchy process (FAHP). Those factors were then overlaid and analyzed according to the multi-source geo-information fusion principal and to the ability of data process and spatial analysis by GIS. Lastly, aquifer water yield property indexes were calculated and zones were identified. The partition result showed that sandstone aquifer water yield property in Yongan Coal Mine was increased from the northeast to the southwest. This finding is consistent with the hydrogeologic understanding of the study area. The distribution of the parameters used to determine aquifer water yield property in this study is relative but will be helpful for engineering design and construction. These analyses are based on data routinely collected as part of the geological exploration data and on published geological reports. The FAHP methodology employed in this study to evaluate sandstone aquifer productivity is considered to be a novel approach to evaluating mine water inrush potential. • Factors were analyzed and standardized by standardization range transform method. • Factors were overlay analyzed by multi-source geo-information fusion and GIS. • Water yield property distribution is relative, and will be helpful to engineering.

TO THE 40TH ANNIVERSARY OF THE EDUCATIONAL AND SCIENTIFIC CENTER OF GEOLOGY AND GEOGRAPHY FACULTY OF ODESSA I. I. MECHNIKOV NATIONAL UNIVERSITY "KRINICHKI"

The main achievements, directions and prospects of the educational and scientific center Krynychky activity, current programs of educational field student practic­es and scientific research are presented in the article. 40 years later, a physical-geo­graphical educational and scientific center Krynychky was founded on the basis of Krynychanska secondary school of the Balta district of Odessa region. Currently, the center is used by staff and students of the Geology and Geography Faculty of Odessa I. I. Mechnikov National University for scientific and/or educational purposes.There were several reasons for the creation of the center in this place, among them the study of the landscape structure of the forest-steppe areas and the study of wetlands (swamps) and solving the problem of their amelioration. Gradually, the range of sci­entific problems expanded. The composition and level of groundwater, agrochemical and agrophysical properties of soils, capacity, dynamics and spatial distribution of snow gusts, as well as observations of soil moisture and its spatial changeability, soil erosion properties, biotic diversity of landscapes, etc., were studied.Most lectures and staff of the Department of Physical Geography and Nature Man­agement, as well as other departments and research laboratories of the Geology and Geography Faculty of Odessa I. I. Mechnikov National University were somehow involved in teaching practice or performing numerous scientific studies in the cen­ter. The study area of the center is a key area in the semi-stationary observations of landscapes and agrocenoses and integrated large-scale zoning and mapping of the territory. More than a dozen diploma theses and a number of scientific dissertations have been defended on the materials of field research of the center. Serious and mul­tifaceted work was performed in the development of a digital database of the center study area with the creation of digital elevation maps, soil cover maps, land categories maps, etc.In recent years, the center has been a constant base for educational field practice for geography students of the Geology and Geography Faculty. The purpose of integrated geographical practice is to master the methods and skills of field research and further in-house work, skills with the simplest tools, and more recently - using software ap­plications in gadgets (eg, pedometer, compass, GPS-navigator, electronic maps, space images, etc.), processing and analysis of the received field data and registration of reports on the performed works.Of particular note is the exceptional importance of field practic­es for geology students. Teachers of the Department of General and Ma­rine Geology studied the geological structure of the territories and de­veloped methodological support for geo-mapping practice in this area. In accordance with the study program of the practice of structural geology and geo-mapping, geology students master the method of route geological survey of the territory, work on outcrops of rocks, study the lithological properties of rocks, make stratigraphic dissection of sedimentary strata, learn to build geological maps of the route and compile geological reports, gain experience in the mining method of miner­al exploration, learn to work in a team.As a result, the educational and scientific center Krynychky has a long and rich history of geographical, paleontological, geoinformation, geological, botanical and soil research which were made during for four decades of its existence. Annual field practices of students are of great importance for the preparation and education of a new constellation of geographers and geologists - teachers and scientists who receive the most valuable skills to perform field research of natural and anthropogenic com­plexes and their interpretation. The center could become a base for conducting field practice for other natural students, as well as a base for the exchange of natural science students between higher education institutions in Ukraine.

STRATIGRAPHY, GEOCHEMISTRY AND METALLOGENY OF THE VENDIAN SYSTEM OF PRIDNESTROVYE

Problem Statement and Purpose At the base of the sedimentary cover of the territory of Moldovan Pridnestrovie the deposits of the Vendian System of the Upper Protero­zoic lie. As a result of drilling works during the geological exploration campaigns of the last century, the data on the stratigraphic position of layers in the section were obtained, the fossil fauna were identified, the geochemical characteristics of rocks by the method of spectral analysis were studied.The purpose of the work is to summarize data on stratigraphy, present a unified local stratigraphic scheme of the Vendian System, make a metallogenetic prognosis for dif­ferent stratigraphic units of the Vendian System of Moldovan Pridnestrovie for further exploration and exploration.Data & Methods The creation of the primary data array was carried out in the training license version of the K-MINE GIS program. Information on wells (more than two hundred) from geological reports was structured and entered into a factual database consisting of a number of tables and reference files interrelated by correlation links. Geostatistical analysis was conducted with the help of the Excel editor to obtain back­ground and abnormal values of ore components. The construction of the schematic maps of contents was made in the Surfer program.Results A local stratigraphic scheme is proposed; the Volyn Series is represented by the Kamenka Formation, the Mogilev-Podolskiy Series includes the Tatarauca Veche, Derlo, Serebriya Formations, the Avdarma Series is represented by the Causeni and Sokol Formations. The justification for the distinguishing of the formations are char acteristic faunal remains identified by E.V. Aseyeva, M.B. Burzin and L.V. Piskun, described earlier in the famous monograph of B.S. Sokolov.The values of abundances of chemical elements for layers of the Vendian System were combined due to insufficiency of spectral analysis data for the formations dis­tinguished. Thus, for the Kamenka Formation, the values of ore components were formed by summing up the values from petrographically different rock types - di­abases, sandstones and weathering crust. The values for the Olchedayev, Lomazov, Cosauti, Lyadova Layers were combined into one column and, despite the fact that they include the deposits of two formations: Tatarauca Veche and Derlo, were united in Mogilev Formation (according to the stratigraphic scheme for the Podolian Plate). Accordingly, the contents for the Bernashovka, Bronnitsa and Zinkovtsy Layers are combined into the Yaryshev Formation.As a result of this analysis, the metallogenic hydrothermal specialization of the dis­tinguished formations has been determined. For example, the Kamenka Formation is characterized by chalcopyritic mineralization, the Mogilev and Yaryshev Formations by polymetallic mineralization. The manifestations of the sedimentary group, which led to the accumulation of industrially significant manifestations of rare-earth ele­ments, are connected with exogenous processes.

Wearing down olivine

An article in Chemical Geology reports the use of magnesium and lithium isotopes to track olivine weathering in soils.

Understanding and conceptualization of the hydrogeology and groundwater flow dynamics of the Nyando River Basin in Western Kenya

Study regionThe Nyando River basin in western Kenya. It is part of the Lake Victoria basin. Study focusAs a first step towards numerical modeling, complementary datasets from different periods have been used to develop a conceptual hydrogeological model for this geologically complex basin. The study focused on characterizing the physical and process structures. Data from geological reports and geo-electrical survey reports were used to establish aquifer extents. Timeline comparison and interpolation of groundwater levels and hydrochemical data analysis were used to define groundwater flow characteristics. New hydrological insights for the regionA highland and a Kano Plains groundwater system exist and are separated by the faults at the Nandi and Kendu escarpments. The groundwater divide between Nyando and Nyamasaria Rivers flowing through the Kano Plains is indistinct, suggesting that their lowland groundwater system is the same. Kano Plains has a shallow and deep groundwater system, both occurring in highly heterogeneous and aquifers; the bedrock here occurs at >250 m below ground level. Generally, the groundwater flow is topography driven towards Lake Victoria, but it is not clear whether it discharges here. Rainfall has minimal effect on long-term groundwater variability. Because groundwater levels do not change significantly over time, steady-state groundwater flow occurs in the plains.

The new fossil record of <italic>Stegolophodon latidens</italic> from the Xiaolongtan locality, Yunnan, China, and the discussion on the age of the <italic>Lufengpithecus keiyuanensis</italic>

Lufengpithecus keiyuanensis from the Xiaolongtan Coal Mine is the earliest known Miocene fossil hominoids in southern China, yet its chronological context has long been subjected to disputes, in being either of late Middle Miocene or early Late Miocene age. This controversy is largely due to the uncertainty of the exact positions of previously discovered fossils in the outcrops, and the different chronological interpretations for some proboscidean and suid fossils from associated fossil faunal assemblages. Here we report the first discovery of Stegolophodon latidens from Xiaolongtan with an unambiguous stratigraphic provenance, which provides important evidence in constraining the age of Lufengpithecus keiyuanensis . Stegolophodon has a very high evolutionary rate of dental morphology, and exhibits a pronounced evolutionary trend with time: from the pentalophodont m3 of the Early Miocene or early Middle Miocene, to the pentalophodont M3 and hexalophodont m3 of the late Middle Miocene, to the 5.5-lophed (five principal lophs followed by an extreme well-developed cingulum) M3 and hexa- to heptalophodont m3 of the early Late Miocene, and to the hexalophodont M3 and hepta- to octalophodont m3 of the middle Late Miocene. The newly discovered Stegolophodon latidens bears a 5.5-lophed M3 and a heptalophodont m3, the second and subsequent lophs/lophids show a slight chevron structure, and the pretrite mesoconelets shift mesially and fuse with the corresponding pretrite anterior central conules, forming a “Y-shape”. These traits are similar to, or even slightly more derived than those of Stegolophodon from the lower part of the Dhok Pathan Formation (9.3−8.3 Ma) in the Middle Siwaliks of the Indian Subcontinent. The materials described here can all be assigned to Stegolophodon latidens which was originally discovered from the Yenangyaung fauna, the lower Irrawaddy Formation of Myanmar, deemed of early Late Miocene age. Revisions on the other proboscidean and suid materials also support an early Late Miocene age for Xiaolongtan Fauna. The new fossils were discovered from the upper part of the lignite layers, close to the bottom of the greyish marls of the Buzhaoba Formation. Based on the original records in the geological reports of the Xiaolongtan Coal Mine, the descriptions of the previous publications, as well as the accounts of the fossil finders, the Xiaolongtan coal mine possesses only one fossiliferous layer, which locates in the upper part on the Xiaolongtan Formation (lignite layers). Therefore, the new fossils situate possibly in the same layer as Lufengpithecus keiyuanensis that were found in the 1950’s and 1980’s. From the recent palaeomagnetic investigations, the age of this fossil layer should be 11.6/11.7 Ma, close to the boundary between the Middle and the late Miocene; however, seems to be slightly older than Stegolophodon latidens from the Siwaliks. Further investigations should be carried out to resolve this inconsistency.

Research of Automatic Generation for Engineering Geological Survey Reports Based on a Four-Dimensional Dynamic Template

Errors and inefficiency may be caused by manual processing of complex templates for the preparation and management of engineering survey reports. To address this problem, this paper analyzes the multidimensional variable features of professional field documents and proposes a generation model of standardized reports based on a four-dimensional dynamic template. This approach splits the standardized report into multiple parts to construct a hierarchical tree that represents the report structure according to the report rules, then stores the tree in a graph database, and finally generates the desired report dynamically by retrieving the relational tree for the template and obtaining the relevant data. The model has been applied to the engineering geological survey report system and is shown to improve the working efficiency and data accuracy of the report preparation. Results indicate that the model is feasible and effective.

Lithological and Tectonic Control on Groundwater Contribution to Stream Discharge During Low-Flow Conditions

Knowing how stream discharge in an ungauged catchment reacts to dry spells is a major challenge for managing water resources. The role of geology on these dynamics is poorly understood. For the Swiss Molasse basin, we therefore explored how the geology influences the groundwater contribution to stream flow during low-flow conditions. Using existing data from geological reports and maps as well as from deep boreholes, we constructed a basin-wide overview of the hydrogeological quality of the bedrock and investigated five catchments in 3D. We found that catchments with the most permeable sedimentary bedrock are least sensitive to low flows (marine sandstone, K = 10−4 to 10−5 m/s, Peff = 5–10%). In contrast, if bedrock K is low (K < 10−6 m/s), the presence of a productive Quaternary volume becomes decisive for groundwater contribution to stream flow. Limitations exist due to a restricted database for K and Peff values of the Molasse and limited information on continuation of lithologies with depth. This emphasizes the need for more hydrogeologically relevant data for the future management of water resources. Our results highlighting what lithotypes favor groundwater contribution to stream flow are valid also in other regions for the assessment of a catchment’s sensitivity to low flows.

Dictionary‐Based Automated Information Extraction From Geological Documents Using a Deep Learning Algorithm

AbstractMassive unstructured geoscience data are buried in geological reports. Geological text classification provides opportunities to leverage this wealth of data for geology and mineralization research. Existing studies of massive geoscience documents/reports have not provided effective classification results for further knowledge discovery and data mining and often lack adequate domain‐specific knowledge. In this paper, we present a novel and unified framework (namely, Dic‐Att‐BiLSTM) that combines domain‐specific knowledge and bidirectional long short‐term memory (BiLSTM) for effective geological text classification. Dic‐Att‐BiLSTM benefits from a matching strategy by incorporating domain‐specific knowledge developed based on geoscience ontology to grasp the linguistic geoscience clues. Furthermore, Dic‐Att‐BiLSTM brings together the capacity of a geoscience dictionary matching approach and an attention mechanism to construct a dictionary attention layer. Finally, the network framework of Dic‐Att‐BiLSTM can utilize domain‐specific knowledge and classify geological text automatically. Experimental verifications are conducted on two constructed data sets, and the results clearly indicate that Dic‐Att‐BiLSTM outperforms other state‐of‐the‐art text classification models.

ГЛИНЫ ТАВДИНСКОЙ СВИТЫ ЭОЦЕНА: ЛИТОГЕОХИМИЧЕСКИЕ И СЕДИМЕНТОЛОГИЧЕСКИЕ АСПЕКТЫ (КЫШТЫРЛИНСКОЕ МЕСТОРОЖДЕНИЕ, ЗАПАДНАЯ СИБИРЬ)

Актуальность. Минеральный состав глин тавдинской свиты изучался неоднократно. Полученные результаты, содержащиеся в геологических отчетах и немногочисленных опубликованных работах, зачастую слабо коррелируются друг с другом. Подобное противоречие вызвано отбором проб для технологических испытаний с различных участков, которые относятся к двум подсвитам, имеющим ряд отличий. Возраст, стратиграфическое положение и химико-минералогические особенности пород, слагающих тавдинскую свиту, остаются дискуссионными и актуальными вопросами, что требует дополнительных исследований. Детальное изучение литологии глин тавдинской свиты принимает важное значение в связи с планами по расширению сырьевой базы и потребностью перепрофилизации части производственных мощностей на выпуск новой товарной продукции. Цель работы: изучение вещественного состава глин тавдинской свиты эоцена Западной Сибири для выявления их генезиса и практического использования Методы: полевые исследования, рентгеноструктурный анализ, рентгенофлуоресцентный анализ, определение огнеупорности, масс-спектрометрия с индуктивно-связанной плазмой, сканирующая электронная микроскопия, литолого-петрографический анализ в шлифах. Результаты. Представлены результаты исследований химического и минерального составов, особенностей литологии и микростроения глинистых пород из Кыштырлинского участка (Тюменская область). Глинистые породы обладают определенной вариативностью минерального состава, но неизменным остается глинистый слюдистый смешаннослойно-смектитовый матрикс. В нижней подсвите глинистая масса пород сложена преимущественно иллитом и смешанослойными образованиями иллит-смектитового состава. Глины верхней подсвиты больше соответствуют каолинит-иллит-монтмориллонитовому типу с примесями пирита, минералов кремнезёма, сульфатов, карбонатов и органического вещества. Формирование таких смешаннослойных масс, вероятно, обусловлено трансформацией обломочных минералов и первичного глинистого субстрата. Установленное распределение редкоземельных элементов индицирует существенные изменения в восстановительно-окислительных условиях морского бассейна на различных этапах его существования. Изученные глины рассматриваются как полиминеральные.

Use of Wyoming Southern Bighorn Mountains Topographic Map Evidence to Test a Recently Proposed Regional Geomorphology Paradigm: USA

Detailed topographic maps covering a high elevation Bighorn-Powder River drainage divide segment in the southern Bighorn Mountains are used to test a recently proposed regional geomorphology paradigm. Fundamentally different from the commonly accepted paradigm the new paradigm predicts immense south-oriented continental ice sheet melt water floods once flowed across what is now the entire Missouri River drainage basin, in which the high Bighorn Mountains are located. Such a possibility is incompatible with commonly accepted paradigm expectations and previous investigators have interpreted Bighorn Mountains geomorphic history quite differently. The paradigm test began in the high glaciated Bighorn Mountains core area where numerous passes, or divide crossings, indicate multiple and sometimes closely spaced streams of water once flowed across what is now the Bighorn-Powder River drainage divide. To the south of the glaciated area, but still in a Precambrian bedrock region, the test found the roughly adjacent and parallel south-oriented North Fork Powder River and Canyon Creek headwaters located on opposite sides of the Bighorn-Powder River drainage divide with North Fork Powder River headwaters closely linked to a 300-meter deep pass through which south-oriented water had probably flowed. Shallower divide crossings located further to the south suggest diverging and converging streams of water once flowed not only across the Bighorn-Powder River drainage divide, but also across Powder River and Bighorn River tributary drainage divides. The paradigm test also found published geologic maps and reports showing the presence of possible flood transported and deposited alluvium. While unable to determine the water source, the new paradigm test did find evidence that large south-oriented floods had crossed what was probably a rising Bighorn Mountains mountain range.

3D Geological Modeling for Yamama Reservoir in Subba, Luhias and Ratawi Oil Fields, South of Iraq

3D geological model for each reservoir unit comprising the Yamama Formation revealed to that the formation is composed of alternating reservoirs and barriers. In Subba and Luhais fields the formation began with barrier YB-1 and four more barriers (YB-2, YB-3, YB-4, YB-5), separated five reservoirs (YR-A, YR-B, YR-C, YR-D, YR-E) ranging in thickness from 70 to 80 m for each of them deposited by five sedimentary cycles. In the Ratawi field the formation was divided into three reservoir units (YR-A, YR-B, and YR-C) separated by two barrier units (YB-2 and YB-3), the first cycle is missing in Ratawi field. 
 The study involves 1 well in Luhais field (Lu-12), 3 wells in Subba field (Su-7, Su-8, and Su-9), and 5 wells in Ratawi field (Rt-3, Rt-4, Rt-5, Rt-6 and Rt-7), the Luhais, Subba, and Ratawi fields located in the Mesopotamia zone (Zubair subzone).
 The reservoir units (YR-C and YR-D) in Subba oil field, and YR-B in Ratawi oil field represent the major reservoir units that characterized by the best Petrophysical properties (the highest porosity, the lowest water saturation, and the best Net Pay Thickness), Luhais oil field has poor to moderate Petrophysical properties and low oil bearing in YR-A, YR-B and YR-C units, and produce heavy oil and salt water from YR-D and YR-E as indicated by low resistivity log reading, and according to the Drill Steam Test (DST) with the description of cutting in final geological reports.

Susceptibility Assessment of Landslides in Alpine-Canyon Region Using Multiple GIS-Based Models

This study explores a comparative study of three susceptibility assessment models based on remote sensing (RS) and geographic information system (GIS). The Lenggu region (China) was selected as a case study. At first, a landslide inventory map was compiled using data from existing geology reports, satellite imagery, and coupling with field observations. Subsequently, three models were built to map the landslide susceptibility using analytical hierarchy process (AHP), fuzzy logic (FL) and certainty factors (CF). The resulting models were validated and compared using areas under the curve (AUC). The AUC plot estimation results indicated that the three models are promising methods for landslide susceptibility mapping. Among the three methods, CF model has highest prediction accuracy than the other two models. Similarly, the outcome of this study reveals that streams, faults, slope and elevation are the main conditioning factors of landslides. Especially, the erosion of streams plays a key role of the landslide occurrence. These landslide susceptibility maps, to some extent, reflect spatial distribution characteristics of landslides in alpine- canyon region of southwest China, and can be used for land planning and hazard risk assessment.

Application of the principle of threeunity for the evaluation of ironore deposits

Subject of research – deposits of iron ore on the principle of threeunity asobjects of natural, needs, economic. The purpose of writing the article is thedevelopment of a resource-based approach to the study of problems, systems ofconcepts and indicators that allow to characterize the resource-cost aspects andevaluation of the results of the study of iron ore deposits in accordance with theirneeds in the process of exploration of mineral resources, conducting search andexploration research and work. Because we are substantiated by the need-resourceconcept of the EG, the system of indicators of iron ore stocks. The methodologyof the work – application of abstract-logical, system-structural and comparativeanalysis (to determine the system of concepts and indicators that allow characterizingresource-cost aspects and evaluating the results of the study of deposits of ironores); analysis (study of the right base for studying the geology of the interior);monographic analysis (with the application of a resource approach); generalization(formation of a system of monetary obligations to the state); interpretation(substantiated systems of concepts using the principle of threeunity and resourceand cost estimates for the study of mineral resources, minerals, conductingexploratory research and work on the needs and resources concept of economicgeology). Results of work-justified: resource approach to evaluation of exploreddeposits of iron ore; Consideration on the principle of fourunity quaternity ofgeological objects as: natural resources (quantity, quality, structure of ores);production and economic resources (costs, production facilities); informationalresources ie information display of geology of subsoil (for example, deposits inthe form of geological maps, geological reports); property resources (fiscal payments from the sale of deposits, iron ore, information about them). Conclusions -using the resource approach and the fourunity principle, iron ore deposits canbe estimated not by geological and economic indicators, but by a system ofquantitative and qualitative indicators, which reflect them as objects of natural,industrial-economic, informational, and fiscal.

Mapping saltwater intrusion with an airborne electromagnetic method in the offshore coastal environment, Monterey Bay, California

Study RegionThe northern coast of the Monterey Bay, California, USA, extending from the coastline to 3.5 km offshore. Study FocusThree-hundred and twenty line-kilometers of airborne electromagnetic (AEM) data were acquired offshore. These data spanned 20 km of coastline, extending up to 3.5 km offshore in water up to 18 m in depth. Inversion of these data resulted in resistivity models extending to depths between 50 and 200 m below sea level. The data were interpreted in conjunction with onshore monitoring well data, hydrologic and geologic reports, and electrical resistivity tomography (ERT) data to locate the freshwater/saltwater interfaces throughout the region. A resistivity-to-water-quality transform was established using well-based water quality and resistivity logging measurements. For resistivity values that could not be converted to water quality with this transform, local auxiliary information was used on a case-by-case basis to interpret the observed features. Some low resistivity anomalies were identified near the shore at depth, which were interpreted to be artifacts of the 1D assumption in the inversion scheme used for these AEM data. New Hydrogeological Insights for this RegionWe found that the acquisition of AEM data provided valuable information about water quality in the offshore extents of the aquifers, a region inaccessible to traditional monitoring methods, but one that plays an important role in the modeling, prediction, and management of saltwater intrusion.

Seismic modelling and its application on designing the seismic survey parameters, a case study of an Iranian oil field

ABSTRACTSpecifying survey parameters is more challenging when dealing with complex structures such as faults due to the complicated wavefield behaviour involved in these structures. Seismic modelling enables geophysicists to have a better understanding of the subsurface image before seismic acquisition, processing and interpretation. In this regard, seismic survey modelling is employed to construct a model close to the real structure, and to obtain very realistic synthetic seismic data. Therefore, a survey designer can investigate the effects of various survey parameters such as shot and receiver positions, and receiver line bearing on the resulting image using illumination and resolution analyses. The primary objective of this study is to apply seismic modelling to designing seismic survey parameters such as receiver line bearing, wavelets and their frequencies to analyse the resolution and illumination of the faulted target. A ray-based seismic model was built using 2D seismic data, geological reports and well logs. A pre-stack depth migration simulator was used to evaluate the effect of source wavelets with different peak frequencies (20, 60 and 80 Hz) on the resulting seismic image. This simulation indicated that a source wavelet with a peak frequency of 20 Hz could not image the target fault plane, but higher peak frequencies (60 and 80 Hz) show higher resolution and better recognition of the fault plane. Therefore, for any wavelet frequency, it is necessary to assess the ability of the fault illumination. The results proved that a survey designer could enhance the image of fault planes in a seismic section by applying ray-based analyses, concerning illumination and resolution of the fault image.

Facies Analysis and Geological modeling of Euphrates Formation in Ajeel Oil Field, Northern Iraq

The current study summarized the construction of a three-dimensional geological model of the Aquitanian sediments age, which represented by the Euphrates and Serikagni formation in Ajeel Oil Field, where Ajeel Oil Field has structural closure towards northwest - southeast. Sedimentary of the current study consist of limestone, dolomitic limestone, dolomite (compose of skeletal grains, non-skeletal grains and cement) and the appearance of some anhydrite rocks. The petrographic study of the Euphrates Formation were prepared using a thin section of wells (Aj-1, Aj-4, Aj-5, Aj-6 and Aj-7), Previous studies and geological reports, as well as use well logs data in the statistical analysis by Petrel software using the Neural Network and Train Estimation Model, for divide sedimentary environments of Euphrates Formation. The petrographic analysis showed mudstone, wackstone, packstone and grainstone facies. The sedimentary environment was then determined and the sedimentary model of the current study rocks in the Ajeel field which compared with Wilson scheme where represented by zones (FZ-6, FZ-8, FZ-7) extend through lagoon environment, back shelf and open shelf, through the sedimentary model was determined the type of Euphrates Formation platform(Rimmed Platform).

Analyzing the Illumination and Resolution in Seismic Survey Designing

Seismic modeling aids the geophysicists to have a better understanding of the subsurface image before the seismic acquisition, processing, and interpretation. In this regard, seismic survey modeling is employed to make a model close to the real structure and to obtain very realistic synthetic seismic data. The objective of this study is to analyze the resolution and illumination of the fault by designing appropriate 3D seismic survey parameters. The ray-based seismic modeling was built using 2D seismic data, geological reports, and the well logs in one of the oil fields in the southwest of Iran. A pre-stack depth migration simulator was used to evaluate the survey geometry on the resulting seismic image. The results proved that a survey designer could improve the image of the target in a seismic section by applying the ray-based analyses, with respect to illumination and resolution studies.

Петрографічне дослідження кам’яних стел доби енеоліту-бронзи з Полтавського краєзнавчого музею

Встановлюється походження сировини кам’яних стел доби енеоліту-бронзи (IV – II тис. до н. е.) з Полтавського краєзнавчого музею імені Василя Кричевського. Досліджено п’ять статуй, серед яких найвідоміша кам’яна стела музею, що датується зазначеним періодом, – так званий Федорівський ідол, знайдений на території Карлівського району, дві стели з Кобеляцького та одна статуя з Кременчуцького району Полтавської області. Походження однієї стели докладно не відоме. За результатами вивчення зразків гірських порід установлено, що сировиною Федорівського ідола є кварцовий пісковик, що містить уламки кременю і вулканічної породи, а також має поровий глинисто-кременистий цемент. Матеріал решти стел визначено як плагіограніт. Один зразок є окварцований, решта представлена біотитовим плагіогранітом. За результатами порівняння сировини досліджених стел зі шліфами гірських порід із Середнього Подніпров’я і Донбасу, сировиною інших пам’яток, що датуються тим самим часом, атакож за літературними даними встановлено, що гранітні стели, найвірогідніше, мають місцеве походження, а саме з району м. Кременчук, де за доби енеоліту-бронзи розроблялися аналогічні породи. Сировина Федорівського ідола виявилася привізною і, найвірогідніше, була видобута на території центрального Донбасу, де існують відслонення аналогічних пісковиків. Важливий факт – те, що гірська порода, з якої виготовлено Федорівський ідол, відповідає сировині відомого Керносівського ідола, який датується тим самим часом і був знайдений на території Дніпропетровської області.