Characteristics Of Deposits Research Articles

"THE POTENTIAL OF GEOTHERMAL SOURCES IN SOUTHERN KAZAKHSTAN FOR HEAT SUPPLY TO RURAL CONSUMERS, the case OF THE ZHAMBYL REGION"

"The article presents the characteristics of geothermal deposits in the south of Kazakhstan and the analysis of the potential of geothermal waters of the Zhambyl region. Moreover, the study carries out the review of various types and methods of using geothermal water for household and its needs. Consequently, it outlines information on thermal boreholes. During the elaboration, manufacture and testing of these combined power units, several scientific and technical issues, such as the choice of the optimal low-boiling working fluid for heat and hot water supply systems were solved. An overview of the refrigerants and vapor compression fluids currently available have been made. The classification and characteristics of secondary heat carriers of various types and temperatures of their use are given. Therefore, it is proposed to use non-azeotropic binary mixtures as working bodies of a closed heat-power circuit. Moreover, an analysis was carried out on the use of non-azeotropic mixtures for heat pumps. It is proposed to use mixtures of refrigerants as working bodies for the second circuit. The specific characteristics of refrigerants are outlined. As a result, a description of the operation scheme of a steam compression heat pump operating in the mode of heat and hot water supply is highlighted. "

Effect of grain size distribution of tailings during the formation of technogenic deposit on the fragmentation index

The most important link in the process chain for creating waste-free technology at concentrating plants is to ensure the possibility of using tailings, where the bulk of non-metallic minerals, rare earth minerals or overburden is concentrated. Increasingly, mining enterprises store their waste, forming man-made deposits. Thus at present time, the development of section technogenic deposits containing tailings is becoming a pressing challenge. The characteristic feature of such deposits is the polydispersity of the developed material, which makes it difficult to determine the fragmentation index. Therefore, the objective of this paper is to study the influence of the grain size distribution of tailings on the fragmentation index during the formation of an technogenic deposit, wherein said index affects the performance of mining and transport equipment, as well as the safety of mining operations. This paper is prepared with the application of the method of mathematical analysis, as well as a laboratory method, including determination of the volume of the pore space by displacement of the liquid phase from a container with a polydisperse mixture and measuring of weight indicators. The polydisperse mixture is represented by a fraction of 0–0,2 mm, 0,2–0,8 mm, 0,8–2,0 mm, 2,0–4,0 mm. 4,0–8,0mm, 3,0–12,0mm. An analysis was made of the influence of 5 indicators on the loosening coefficient. As a result of the study, it was found that the main criterion affecting the loosening coefficient is the ratio of coarse to fine class in the mixture, and not the size of the weighted average particle in it, and the smaller this ratio, the lower the loosening coefficient approaches 1. Class 1 reception in subsequent calculations. The results obtained will become the basis for studying the loosening factor in the development of man-made deposits, represented by tailings, and require further improvement of the theoretical foundations and industrial use.

Сomposition and structure features of the Vikulov productive deposits (Krasnoleninsky arch) and their influence on reservoir properties

Both sedimentological factors and secondary processes of lithogenesis influenced the formation of porosity and permeability properties of the reservoir rocks of the Vikulov suite of the Krasnoleninskoe field. The former includes the conditions of sedimentation of the deposits of the Vikulov suite, which at the initial stages of its formation were controlled by the development of a system of incised river valleys, the stages of filling of which, like their composition, have their own characteristics. Also, various genetic types of deposits were formed here. The formation of the upper part of the Vikulov suite took place in a shallow-marine setting, in conditions of storm and wave shallow water, which affected the thin-layered structure of the VK1-3 reservoir. On the other hand, in the sections of a number of wells, dense interlayers are noted, the formation of which is associated with both sedimentation and superimposed processes in lithogenesis, including the formation of hydrocarbon deposits. Therefore, the prediction of the distribution of productive reservoir rocks is the main task when creating a petrophysical model of the field, and to solve this problem, the methods of lithofacies and staged core analysis are used in the work.

Carboniferous marine deposits of the Tontal section suggest that no Protoprecordillera existed along the Western Gondwana margin

We present new palaeontological and stratigraphic data from a poorly known section located in the Tontal Range, Argentina, whose importance is key to defining the character of a hypothetical Carboniferous mountain chain, the Protoprecordillera. The Tontal Range composed the core of the hypothetical Protoprecordillera, also called the Tontal arch. The section described here comprises Mississippian and Pennsylvanian marine and mixed marine–terrestrial units that were deposited within a proglacial (non-fjord) environment. A new correlating scheme of Tontal section units is brought based on new biostratigraphic data plus the recent development of a stratigraphic order of Carboniferous units cropping out only 15 km away. The lowermost unit in the Tontal section is Del Ratón Formation conglomerate, which passes upwards into glaciomarine shales correlated with the El Planchón Formation that bears marine bivalves and palynomorphs suggesting a Serpukhovian (Upper Mississippian) age. El Planchón is overlain by the barren Churupatí Formation, with lower units of shallow marine, fan-deltaic conglomerate, passing to fluvial redbeds. The overlying Del Salto Formation has intense intraformational folding due to slumping at its base, and consists of sandstone, organic-rich shale, and shelf carbonate, the latter containing marine invertebrates and palynomorphs that suggest a Bashkirian (Lower Pennsylvanian) age. The Tontal section represents a marginal position within a previously defined strike-slip basin (Milana and Di Pasquo, 2019) that was active during most of the Carboniferous. It was deposited in a shallow marine shelf beside a hummocky coastal landscape, the erosion of which provided rounded gravels deposited in Gilbert-type deltas with associated slumps. We found no indication this area hosted any kind of glaciers, and most of the time it was below sea level. These observations, along with the lack of any mountain-side complex or any alpine-valley glacio-related depositional features remain at this, or any neighbouring sections; suggest that there was no Protoprecordillera mountain chain. Correlation with nearby sections also suggests this margin was not influenced by any prominent topographic highs during the depositional time of the Tontal section (upper Mississipian to Pennsylvanian), but rather that this area was located near sea level, potentially with emergent and positive areas along both margins of the strike-slip basin that allowed preservation of the oldest Carboniferous units of this region. On the other hand, the tendency for generalised subsidence during the Upper Carboniferous over most of the Precordillera, may respond to the development of a volcanic arc westwards over the present Cordillera, associated with the activation of a subduction zone in the present-day Chile, turning most of the area into retroarc basins.

Integrating МGIS Micromine Origin & Beyond into the educational process at the Geological Prospecting Faculty of the M. K. Ammosov North-Eastern Federal University

Currently, the geological fild places special attention on modern technology and computer programs. The article describes the collaboration between the North-Eastern Federal University and LLC «Micromine Rus» aimed at educating students in modern technologies of the mining and geological industry. The article considers the issues of training geological specialists at the Geological Prospecting Faculty of the North-Eastern Federal University with the direct support of Micromine Rus and integrating Micromine Origin & Beyond software into the educational process. Students engaged in geological modeling in the computer class can visualize and understand the geological characteristics and features of deposits, participate in the student league of the international engineering championship «CASE-IN». This allows graduates to acquire digital competencies essential for successful employment and quick adaptation to the industrial process at mining and geological enterprises.

Thermal infrared spectral characteristics of martian dust deposits and evidence for atmosphere-regolith interactions

It has been hypothesized that the dust component of the Martian surface is globally homogeneous, based on chemical similarity between landing sites and spectral similarity from select areas within bright regions. We tested that hypothesis by producing the first near-global data set of surface spectral emissivity (excluding polar regions) across the ∼233–508 and 825–1650 cm−1 (∼20–50 and 6–12 μm) spectral ranges from Mars Global Surveyor Thermal Emission Spectrometer data and using various data reduction techniques to search for any spectral heterogeneity in bright regions that might be present. We found no unequivocal evidence for spectral heterogeneity, supporting the hypothesis that dust is globally homogenized. The global emissivity product permits new spectral parameter maps and preliminary assessments of atmosphere-regolith interactions. We produced the first map of the Christiansen feature (CF) and show that, unlike on the Moon, where CF is a proxy for bulk silica content, CF position on Mars is primarily associated with dust cover. We produced an updated map of the 1630 cm−1 emissivity peak that arises from bound H2O in fine-particulate material and show that the peak is nearly ubiquitous across the Martian surface, including in dark regions with relatively low dust cover. This is attributed to minor amounts of dust disproportionally contributing to the spectral signal in the ∼1630 cm−1 region. We show that regions within the equatorial dust deposits with higher annual modeled frequency of nighttime CO2 frosts are more likely to have lower emissivity in the ∼1350-1400 cm−1 region, consistent with a higher fraction of unconsolidated dust. This provides the first spectral evidence for a previously hypothesized regolith gardening process via a diurnal CO2 cycle, representing an important surface-atmosphere interaction that may contribute to near-surface porosity and affect diffusive exchange of H2O between atmosphere and hydrated solids (ice, minerals) in the regolith.

Morphology and Mineralogical Characteristics of Detrital Iron Deposit of North Odisha Iron Ore Craton, India

Morphology and Mineralogical Characteristics of Detrital Iron Deposit of North Odisha Iron Ore Craton, India

Experimental constraints on the volatility of germanium, zinc, and lithium in Martian basalts and the role of degassing in alteration of surface minerals

AbstractThe surface of Mars is enriched in Cl and S which is linked to volcanic activity and degassing. Similarly, elevated Ge and Zn levels in Gale crater sedimentary bedrock indicate a magmatic source for these elements. To constrain the relative effects of Cl and S on the outgassing of these trace metals and chemical characteristics of primary magmatic vapor deposits incorporated to Martian surface, we conducted a set of degassing and fumarolic alteration experiments. Ge is found to be more volatile than Zn in all experiments. In S‐bearing runs, the loss of Ge and Zn was less than any other experiments. In Cl‐only runs, degassing of Zn was more than twice that of Ge within the first 10 min and percent loss increased for both elements with increasing time. In Cl + S runs, S‐induced reduction of GeO2 and ZnO to metallic Ge and Zn switches the preference of chloride formation from Zn to Ge. Up to 90% of Ge and Zn loss in the 1‐h no volatile‐added (NVA) experiments might be due to the small amounts of Cl contamination in NVA mixes via other oxides used for synthesis. Alteration experiments show different phases between 1‐h and 24‐/72‐h runs. In 1‐h runs, anhydrite and langbeinite dominate while in 24‐/72‐h runs halite and sylvite dominate the condensate assemblages. S‐bearing phases form as the intermediate products of fumarolic deposition, while chlorides are common when the system is allowed to cool gradually. One‐hour exposure was sufficient to form alteration phases and vapor deposits such as NaCl, KCl, CaSO4, and langbeinites on the Martian analog minerals. These salts were identified in Martian meteorites and in situ measurements. Our results provide evidence that volcanic degassing along with fumarolic alteration could be a potential source for the enrichment and varying abundances of Cl, S, Fe, Zn, Ge in Martian surface, as well as a cause for Ge depletion in shergottites.

Submarine Geomorphology and Sedimentary Features around the Egadi Islands (Western Mediterranean Sea)

In this paper, the physiography, geomorphological features, and sedimentary bedforms of the offshore Egadi Islands (Italy) have been illustrated and mapped through an integrated analysis of high-resolution bathymetric, seismo-acoustic, and sedimentological data. The study area is characterized by a wide, up to 25 km, continental shelf which is separated by a NNW-trending linear incision, the Marettimo Channel, along which several erosional and depositional features have been detected and mapped. Sedimentary prograding wedges were detected at water depths between 100–125 m along the shelf margin, which accumulated during the sea-level fall and lowstand stages of the last glacio-eustatic cycle (post- MIS 5.5). This study detected several slope breaks defining scarps across the continental shelf, which were interpreted as coastal cliffs that originated during the post-LGM eustatic sea-level rise. Several fields of different types of sedimentary bedforms, including 2-D and 3-D hydraulic dunes and sorted bedforms, were found across the continental shelf, providing evidence of a high hydrodynamic regime affecting the seafloor. Further on, this study recognized erosive and depositional features related to bottom currents (contourites) in the Marettimo Channel. These findings provide a better understanding of the morpho-sedimentary evolution of the Egadi Islands offshore in the latest Quaternary. Moreover, they offer essential scientific support for effectively managing the most valuable priority habitats for conservation, such as the Posidonia oceanica meadow and coralline algae bioconstructions (Coralligenous habitat).

Sedimentary records in dry karstic valleys: The case of Mambaí, central Brazil

Karstic areas in Central Brazil show significant depositional and erosive facies placed within abandoned dry valley-systems and associated with fluviokarstic dynamics. These valleys have distinct depositional characteristics that offer sedimentary records of both past climatic events in the region and its current fluviokarstic system. The purpose of this paper is to point out and characterize such sedimentary packages, protected by dry valleys that were deposited up until the fluviokarstic transition, thus enabling the correlation of such sediments to past climatic events. The study is based on a combination of geomorphic and sedimentological analyses through the employment of multiple techniques, such as mineralogy, geochronology, stable isotopes, and granulometry, to the analysis of our case studies. These are the three dry valleys around the Ventura, Pedras and Extrema rivers, which in turn comprise the River Vermelho Basin, northeastern Goiás State. Our results suggest that the valleys contain fluvial deposits remnant from the transition of superficial fluvial flow to the underground karstic system. Records provide a general view of the depositional stages placed before and up until the period of fluvial capture in terms of their morphology, dynamics, and sediment architecture. OSL ages indicate that fluviokarstic processes had been in operation since 23 Ka, when the oldest river capture was found to have occurred. Depositions occurred in a reasonably continuous manner, mainly during the last 3.5 Ka, and concentrated around relatively dry and wet events, exhibiting typical depositional gaps in fluvial environments. Consequently, no relationship between the depositions and paleoclimatic events were observed for the analyzed fluviokarstic system.

Paleoclimatic conditions during the accumulation of the Upper Jurassic and Lower Cretaceous organic carbon-rich deposits of the Ulyanovsk-Saratov trough (eastern Russian platform)

Relevance of the work. Black shale horizons may reflect abrupt paleoclimate changes. In the northeast of the Ulyanovsk-Saratov Trough (UST), two black shale horizons widely occur, the Middle Volgian Promzino Formation and the Lower Aptian Ulyanovsk Formation. Despite years of research, the role of paleoclimate in their accumulation is still under discussion. The aim of the research was to assess the climate as a factor of the accumulation of the Middle Volgian and Lower Aptian organic carbon-rich deposits in the northeastern UST. Methods. To reconstruct paleoclimate and to evaluate its impact on the black shale deposition, a comprehensive isotope study of calcitic and aragonitic shells of several groups of benthic and pelagic organisms was performed. Besides, the lithological and geochemical features of organic carbon-rich and host deposits were studied using optical microscopy, XRD, and pyrolysis. Results. Isotope study allowed to construct benthic and pelagic palaeotemperature curves and to reconstruct paleoclimate in the UST during the formation of black shales. Based on these data and data on lithological and geochemical features of sediments, the depositional mechanisms of the Promzino and Ulyanovsk Formations were clarified. Conclusions. No causal link has been revealed between climate changes and the deposition of the Middle Volgian black shales. At the end of the Middle Volgian, a short-term cooling has been recorded, probably related to the volcanic activity of the northern Tethyan margin. The Lower Aptian black shales were formed during the hyperthermal. This hyperthermal controlled the accumulation of organic carbon-rich sediments by increasing the input of nutrients and/or providing conditions for its stratification and stagnation.

The Hajdúböszörmény-Csege-halom Hoard and its Related Finds in Europe

Abstract The study discusses a bronze hoard well-known through Europe from Hajdúböszörmény-Csege-halom (Hajdú-Bihar County, Hungary) which consists of weapons and a bronze vessel set. On one hand, the aim of the study is to introduce the newest results related to this unique eponymous find. On the other hand, it analyses the assemblage in a European context, characterize and interpret its supra-regional connections based on the composition and depositional features of the hoard based on conventional typo-chronology and correspondence analysis.

Depositional environment and aquifer properties of the Sherwood Sandstone Group in the Cleveland Basin based on investigations at Woodsmith Mine

A major mining project by Anglo American plc at Woodsmith Mine is targeting deep polyhalite deposits in the Cleveland Basin of North Yorkshire. The mine shaft design included hydrogeological assessment of the full 1600 m hydrostratigraphic sequence to be intersected. Of this sequence the most significant aquifer that will be intersected is the Sherwood Sandstone Group (SSG), which will be encountered at depths of between 800 and 1050 m below surface. Deep exploratory cored boreholes were completed at the site to allow both laboratory and field testing. The methods used to determine the aquifer characteristics comprised geotechnical laboratory testing of rock core and oilfield downhole wireline technology. Geotechnical triaxial tests were used to determine the horizontal and vertical permeability of rock core recovered from deep exploration boreholes. Wireline Elementary Log ANalyses (ELAN) and Modulation Dynamic Testing (MDT) were used to determine hydraulic conductivity and porosity of the SSG sequence encountered. Formation Micro Imager (FMI) was used to determine sedimentary depositional features. This paper presents a review of the ground investigation data collected to characterize anisotropy between horizontal and vertical flow within the SSG in this part of the Cleveland Basin. Thematic collection: This article is part of the Hydrogeology of Sandstone collection available at: https://www.lyellcollection.org/cc/hydrogeology-of-sandstone

Arthroscopic decompression of calcific tendinitis without cuff repair.

The aim of this study was to investigate the outcomes of arthroscopic decompression of calcific tendinitis performed without repairing the rotator cuff defect. A total of 99 patients who underwent treatment between December 2013 and August 2019 were retrospectively reviewed. Visual analogue scale (VAS) and American Shoulder and Elbow Surgeons (ASES) scores were reviewed pre- and postoperatively according to the location, size, physical characteristics, and radiological features of the calcific deposits. Additionally, the influence of any residual calcific deposits shown on postoperative radiographs was explored. The healing rate of the unrepaired cuff defect was determined by reviewing the 29 patients who had follow-up MRIs. Statistically significant improvement from pre- to postoperation was seen in all VAS and ASES scores for each group, but no statistical differences were seen between the postoperative scores according to the differences in the features of the calcific deposits. When residual calcification was observed postoperatively, the mean ASES and VAS (rest) scores improved significantly to 95.0 (SD 5.6) and 0.0 (SD 0.0), respectively (p = 0.006 and p < 0.001), and did not differ from those who had the complete removal. Of 29 patients who had follow-up MRIs, six (20.7%) showed signs of an interstitial tear. This group's mean postoperative ASES and VAS (rest) scores improved to excellent levels of 96.0 (SD 3.7) and 0.0 (SD 0.0), respectively, and were similar to those of the 23 patients with normal MRI appearances. Arthroscopic removal of calcific deposits without repairing the rotator cuff defect resulted in significant improvement in function and pain level, regardless of the deposit's location, size, type, and whether or not complete excision was achieved. Despite leaving the defects unrepaired, in the limited number of patients with follow-up MRIs, 23 of 29 patients (79.3%) showed good healing, and the rest, who had persistent signs of interstitial defects on the MRIs, still had excellent outcomes. The removal of calcific deposits without repairing the cuff defects provided excellent outcomes.

Depositional cycles in a rift lacustrine basin linked with tectonics, climate, and source rocks and reservoirs development: Lower Cretaceous in Naiman sag, Songliao Basin, Inner Monglia, Northeast China

In order to improve understanding of the depositional evolution processes in rift lacustrine basins in Northeast China under Early Cretaceous greenhouse climate fluctuations, the roles of tectonics and climate along with the development of source rocks and reservoirs in the evolution of continental rift lacustrine basins in Naiman sag, Songliao Basin, Inner Monglia, were studied. Based on the detailed facies analysis of the subsurface boreholes, eight facies were identified in the Lower Cretaceous strata of Naiman sag and were grouped into three facies associations, namely fan delta, littoral to sublittoral lacustrine, and deep lacustrine. Based on the depositional characteristics, in combination with lacustrine evaporites and carbonate deposition, organic matter preservation, and lake depth, the Lower Cretaceous strata of the Naiman sag was further subdivided into four lake stages, namely initial formation of lake (Stage 1), sediment-fill shallow lake (Stage 2), rising to a high lake (Stage 3), and lake closure (Stage 4), respectively. The lake evolution in the Naiman sag was driven by both tectonics and climate changes. Fault-driven subsidence was likely contributed to episodic changes in accommodation and lake formation (Stage 1), expansion (Stage 3) and shrinkage (Stage 4). A combination of regional and global climate overprint controlled the sedimentary characteristics, depositional trends, and sediment and water supply. The global climate of ocean anoxic events 1a and 1b (OAE1a and OAE1b) may have effects on anoxic conditions of Stages 1 and 3, respectively. During regional climate changes between arid, hot and humid, seasonal climate tended to form evaporite deposits and multiple layers of oil shale deposits in Stage 1. During the more humid regional climate, steady runoff tended to form fan delta deposits prograding into the lake basin in Stages 2 and 4 and thick-bedded oil shale deposits in Stage 3. The development of source rocks is linked with lake formation and expansion stages (Stages 1 and 3), and the source rocks are mainly preserved in the deep lacustrine and littoral to sublittoral lacustrine environment. The development of reservoirs is associated with lake formation, sediment-fill, and shrinkage stages (Stages 1, 2, and 4), and the reservoirs are mainly preserved in the fan delta environment.

Susceptibility of the Climate Resilient Landforms of the Coastal Tract of Odisha and West Bengal, India

Abstract Wide sea beaches, beach ridges, barrier sand spits, sand dunes, and climate-sensitive tidal flats with mangrove forests on the coast of Odisha and West Bengal are the products of coastal process dynamics during the middle to late Holocene epoch under a stable sea level stage. These features are resilient to the global climate change phenomenon under natural conditions with the continuous supply of sediments and the spread of habitats that protect the coastal lowlands behind them against storms and inundations. Both the geomorphological and ecological systems of the depositional features were developed and optimized into matured stages before human intervention into the coastal system. These features were well developed along the storm-affected shoreline of the eastern coast of India with the supply of sediments into the coastal zones by river inputs, longshore current transport, cross-shore transport through storms, transgressive seas during the Holocene epoch, seasonal wind waves, and aeolian deposits. After assessing the climatic sensitivity stress, exposure index, adaptive capacities, and coastal vulnerabilities of the study area, the final result shows high susceptivity scores for the landforms that represent low resilient capacity; whereas, the coastal tracts of Purba Medinipur, and Sundarban represent low resilient capacity; and the coastal tract of Odisha reflects high to moderate resilient capacity. In the perspective of the global climate change phenomenon and human intervention into the coastal systems, the present study was conducted to find out the temporal changes of the coastal depositional features, to estimate the sensitivity of the features, and finally, to enquire about their susceptibility to the impact of cyclonic storms and the rapid rate of sea-level rise process currently occurring in the region of the tropical coast.

Anomalous position of Paleozoic faults of Western Donbas

Statement of the general problem. The oil and gas-bearing province of Eastern Ukraine is located in the Dnipro-Donetsk Basin (DDB). It covers the Paleozoic structural floor and is buried under younger sediments. The Paleozoic structural floor of the territory is represented as a long rift graben. The maximum thickness of the sedimentary cover in the graben is 15–17 km. According to geophysical data, the thickness of the earth's crust is 31–32 km under the axial part of the DDB and increases towards the sides. But according to the maximum thickness and facies characteristics of the Paleozoic deposits, the thickness of the Earth's crust below them could not exceed 20 km. The modern thickness is 1.5 times higher. Therefore, such a geological-geophysical model of the structure of the DDB is contradictory. Analysis of recent research and publications. The removal of the contradiction is possible due to the detection of a series of Hercynian thrusts with total amplitude of thrusts of the order of 50 km. Such thrusts began to be established on the northern and southern flanks of the DDB. Hercynian thrusts have a southwestern vergence. In the north, the Voronezh crystalline massif is pushed onto the DDB along the Noviy thrust with an amplitude of 9–10 km. In the south, the South Donbas melange zone is established, which pushes the folded Donbas onto the Ukrainian shield. On its continuation to the northwest is the southern side of the DDB - the so-called Southern monocline. The well-studied Pavlograd-Petropavlovsk coal mining district of Western Donbass with operating coal mines is located within its borders. An unsolved part of the overall problem. Numerous faults with relatively small amplitudes are established within the Paleozoic Southern Monocline. Together, they form a system of horsts and grabens with a north-western extension. But the bottom parts of the grabens are 1–3 km higher than the tops of the horsts. Such a geological situation is anomalous. This indicates the post-fault dislocation of the horst-graben system as a whole. The purpose of the article is identification of the causes of the anomalous structural position of the graben-horst system in the modern geological structure of the Southern Monocline and in the general model of the geological structure of Eastern Ukraine. Research materials and methods. Were involved more than 390 geological sections, constructed based on the data of more than 10,000 wells. Of them, 265 wells revealed the folds that are being analyzed. In addition, were used data of catagenetic transformations of the sedimentary section. Presentation of the main research material. The South Donbas mélange zone falls to the northeast and continues under the Southern Monocline. It is located in the upper block of this regional thrust structure and is in an allochthonous setting. According to geological data, the true amplitude of the thrust of Western Donbas on the Ukrainian shield is 15–20 km, and the vertical component of this amplitude exceeds 3 km. Such spatial parameters explain the abnormality of the structural position of the horsts and grabens of Western Donbass - their southwestern flanks were significantly raised relative to the northeastern flanks during thrusting. Scientific novelty. Therefore, in the modern geological structure, the Dnipro-Donetsk "basin" is not a rift, but a post-rift Hercynian folded region. It is formed by high-amplitude thrusts on the northern and southern flanks. The Hercynian fold region is buried under Mesozoic and Cenozoic sediments and is further complicated by Laramian and Attic fold-thrust dislocations of lesser intensity. Conclusions. The thrust model brings the geophysical parameters into the correspondence with the geological data and is confirmed by the actual material.

Types, characteristics and geological significance of event deposits of Chang 9 Member of Triassic Yanchang Formation in southwestern Ordos Basin, NW China

Through core observation, thin section identification, and logging and testing data analysis, the types and characteristics of event deposits in the ninth member of Yanchang Formation of Triassic (Chang 9 Member) in southwestern Ordos Basin, China, are examined. There are 4 types and 9 subtypes of event deposits, i.e. earthquake, gravity flow, volcanic and anoxic deposits, in the Chang 9 Member in the study area. Based on the analysis of the characteristics and distribution of such events deposits, it is proposed that the event deposits are generally symbiotic or associated, with intrinsic genetic relations and distribution laws. Five kinds of sedimentary microfacies with relatively developed event deposits are identified, and the genetic model of event deposits is discussed. Seismites are mainly developed in the lake transgression stage when the basin expands episodically, and commonly affected by liquefaction flow, gravity action and brittle shear deformation. Gravity flow, mainly distributed in the high water level period, sandwiched in the fine-grained sediments of prodelta or semi-deep lake, or creates banded or lobate slump turbidite fan. It is relatively developed above the seismites strata. The volcanic event deposits are only seen in the lower part of the Chang 9 Member, showing abrupt contact at the top and bottom, which reflects the volcanic activity at the same time. Anoxic deposits are mostly formed in the late stage of lake transgression to the highstand stage. Very thick organic-rich shales are developed in the highstand stage of Chang 9 Member, and the event deposits in the depositional period of these shales are conducive to potential reservoirs.

Choice of access for underground mining for feasibility studies

This study presents a review of the methodology for choosing the type of access and exploitation methodology for underground mines, being the choice of the type of access, one of the initial stages of the conceptual projects. To this end, in addition to literature verification, technical feasibility reports of recent projects were analyzed, made available by mining companies listed on the Toronto Stock Exchange. In this report, data were extracted referring to technical and productive characteristics of the projects, thus allowing comparison with classic methodologies for the choice of types of access and the compilation of a new flowchart, adhered to the current mining industry. The data from the projects were separated considering the mining methods with the largest number of samples, as well as the productive and mineral deposit characteristics. As a result, a chart is presented for the choice of access and mining method as a function of productive characteristics, ore body geometry and rock mass quality. Updating the limits considered for depth and daily production corresponded to a significant improvement in the response of the suggested access type and made it compatible with that presented in the feasibility projects.

Slagging-fouling evaluation of empty fruit bunch and palm oil frond mixture with bituminous ash coal as co-firing fuel

The empty fruit bunch (EFB) and palm oil frond mixture, called EFFR, can be utilized as co-firing fuel for coal-fired power plants to reduce carbon emissions. However, the addition of EFFR can influence the ash deposition characteristic of power plant fuel due to its high chlorine and alkali content. This study evaluates the slagging-fouling propensity of EFFR when blended with bituminous ash coal in several compositions. Theoretical methods using indices and the SCK ternary phase diagram, experimental procedure with drop tube furnace combustion, and ash observation methods utilizing visual and instrumental observations are carried out. The results show that co-firing EFFR can effectively reduce ash deposition. The slagging-fouling risk tendency slightly increases, adding up to 15 wt% EFFR has a higher slagging tendency, while the addition of 20 wt% EFFR has a higher fouling tendency. According to a thorough evaluation, co-firing 5–20 wt% EFFR with bituminous coal is still acceptable.