Coal Exploration Research Articles

Molecule structure and ultrasonic wave velocity of different ranking coals: An experimental perspective

Ultrasonic wave velocity is an important manifestation of coal elastic properties and is extremely useful for coal and coalbed methane exploration. In this study, we focused on analyzing how the molecular structure affects the elastic ultrasonic wave velocity. High-resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FT-IR) were used to explain the coal’s molecular structure. Ultrasonic wave velocity measurements were then used to determine the elastic parameters of coals of different ranks. From an elasticity theory point of view, the molecular structure of coal is a simple system consisting of two substructures. The results showed that the correlation between the ultrasonic wave velocity and the molecular structure differs in different coalification stages. In the first stage (Rr = 0.6%–∼1.6%), the ultrasonic wave velocity of coal keeps decreasing during the maturation process due to the aromatization of the coal molecular structure and the cleavage of alkyl side chains. In the second stage (Rr = 1.6%–∼3.0%), the average layer size (La) of the coal molecular structure increases and the average interlayer space decreases, which makes the ultrasonic wave velocity of coal increase continuously. The evolution of the molecular structure of coal is an important influencing factor for its elastic properties. The irregular parts (alkyl side chains and functional groups) play a major role in elastic ultrasonic wave velocity, followed by the average layer size (La) and the average interlayer spacing (d) of aromatic layers. It was determined that the relationship between the coal rank and ultrasonic wave velocity of coal without macro-fractured can be interpreted as the evolution of the molecular structure (two substructures), and the ultrasonic velocity measurement methods were applied to investigate the coal structure. These relations can be useful for geophysical exploration of coal and coalbed methane.

Environmental life-cycle assessment of waste-coal pellets production

Abstract Industrial decarbonization is crucial to keeping the global mean temperature <1.5°C above pre-industrial levels. Although unabated coal use needs to be phased out, coal is still expected to remain an important source of energy in power and energy-intensive industries until the 2030s. Decades of coal exploration, mining and processing have resulted in ~30 billion tonnes of waste-coal tailings being stored in coal impoundments, posing environmental risks. This study presents an environmental life-cycle assessment of a coal-processing technology to produce coal pellets from the waste coal stored in impoundments. It has been shown that the waste-coal pellets would result in the cradle-to-gate global warming of 1.68–3.50 kgCO2,eq/GJch, depending on the source of electricity used to drive the process. In contrast, the corresponding figure for the supply of conventional coal in the US was estimated to be 12.76 kgCO2,eq/GJch. Such a reduction in the global-warming impact confirms that waste-coal pellets can be a viable source of energy that will reduce the environmental impact of the power and energy-intensive industries in the short term. A considered case study showed that complete substitution of conventional coal with the waste-coal pellets in a steelmaking plant would reduce the greenhouse-gas emissions from 2649.80 to 2439.50 kgCO2,eq/tsteel. This, in turn, would reduce the life-cycle greenhouse-gas emissions of wind-turbine manufacturing by ≤8.6%. Overall, this study reveals that the use of waste-coal pellets can bring a meaningful reduction in industrial greenhouse-gas emissions, even before these processes are fully decarbonized.

Determination of Coal Ash Content by Neutron-Neutron Logging

The research is aimed at assessing the possibility of studying the ash content of coal seams using neutron-neutron logging in coal exploration wells drilled at the outcrops of coal seams under loose deposits using the materials of experimental work in the South Yakutsk coal basin. The prospects of using neutron-neutron logging to study coal well sections, on the one hand, is determined by the fact that hydrogen content in coal seams normally exceeds its content in the host rocks, and, on the other, by the small cross-sections of neutron capture by carbon. Within the same coal grade, an increase in its ash content both means a decrease in its hydrogen content and an increase in the content of elements with a higher capture cross section. Experimental studies were carried out at the Syllakh coal deposit. An IBN-8-1 type plutonium-beryllium source with an output of 5*104 neutrons/s was used as a fast neutron source, and a highly efficient SNM-17 type helium gas-discharge counter was used as a slow neutron detector. The logging depth provided by the equipment was 10 - 30 cm. During the processing of the obtained field data, a correlation was established between the count rate of neutron-neutron logging and coal ash content. It should be noted that the functional dependence of the count rate of neutron-neutron logging on ash content is not continuous – in the range of ash content of 45 - 55% a certain discontinuity point is observed, after which the functional dependence changes. To simplify the assessment of the dependence, the range of rock ash content above 45% is neglected since bituminous coals with an ash content of more than 45% are classified as carbonaceous rock and are not of industrial interest. A close correlation is established between the count rate of neutron-neutron logging and coal ash content. According to the results of statistical processing, the correlation coefficient is 0.97, which makes it possible to quantitatively determine the ash content according to neutron-neutron logging data. The absolute errors in ash content determination by neutron-neutron logging over the entire dataset are up to 3.625 %. The degree of analytical moisture influence on the data of neutron-neutron logging in determining coal ash content is estimated. No regular changes in the count rate of neutron-neutron logging due to a change in the analytical moisture index have been established. It is noteworthy that, with a sufficiently large dispersion value of the analytical moisture index, the trend line of this parameter regularly changes synchronously with the trend lines of ash content and count rate.

Health impact assessment of air pollution in an area of the largest coal mine in Brazil.

Coal exploration and burning activities are among the activities with the greatest potential to cause atmospheric pollution due to the combustion process of this mineral and the consequent release of particles that, in significant quantities, can pose a potential health risk, mainly respiratory and cardiovascular diseases. The Candiota region, in the extreme south of Brazil, concentrates 40% of the national reserves of mineral coal, and its burning is capable of releasing air pollutants, including particulate matter (PM). Some environmental and epidemiological studies have been carried out in the region, but so far, there is no investigation to estimate the impact of PM on health outcomes. The current study aimed to estimate the mortality attributed to the PM, as well as the benefits in health indicators associated with the reduction of air pollution to the limits set forth in local legislation and the WHO. Daily data on PM levels collected from an air quality monitoring station over a year were used, as well as population data and health indicators from 7 cities influenced by mining activities, such as total mortality and cardiovascular diseases and hospitalizations for cardiac and respiratory problems. In a scenario where PM levels are within legal limits, a percentage greater than 11% of cardiovascular deaths was attributed to pollution by PM2.5, and the reduction in PM10 and PM2.5 levels may be responsible for the increase in the expectation of life in up to 17 months and monetary gains of more than $ 24 million, due to the reduction in hospitalizations and mortality. Studies of this nature should be important tools made available to decision-makers, with a view to improving environmental laws and a consequent improvement in the quality of life and health indicators of the population.

Experimental research on the law of the deformation and damage characteristics of raw coal/ briquette adsorption-instantaneous pressure relief

In order to clarify the characteristics of gas-bearing coal adsorption-instantaneous pressure relief deformation, and reveal the mechanism of the effect of gas desorption on the outburst. Through the gas-bearing coal adsorption-instantaneous pressure relief test system, the adsorption-instantaneous pressure relief test using briquette/raw coal samples was used to conduct a comprehensive comparison and analysis of the deformation characteristics of the two coal samples. Studying the damage of coal with different adsorption characteristics gases under the condition of adsorption-instantaneous pressure relief, and use strain gauges to monitor the microscopic deformation of the coal, and analysis of the adsorption of briquette/raw coal at constant pressure-instantaneous similarities and differences of deformation characteristics during pressure relief. “The results showed that under the same test conditions of adsorption equilibrium pressure, the degree of crushing of coal samples after instantaneous pressure relief is CO2 > CH4 > N2. At the moment of instantaneous pressure relief, the strain of the raw coal/briquette suddenly decreases, characterized by swelling deformation. Under the same temperature and pressure conditions, the expansion energy of CO2 is the highest, followed by CH4 and N2. Due to the raw coal has not completely destroyed the joints, only elastic deformation occurs, and the strain rises rapidly within a short period of time, resulting in shrinkage deformation. However, during the instantaneous pressure relief of the briquette, swelling and deformation occurred, and the coal was destroyed. The research results have certain significance for the exploration of coal and gas outburst mechanism.

Coordinated Exploration Model and its Application to Coal and Coal‐associated Deposits in Coal Basins of China

AbstractChina is a top world producer of coal resources with numerous coal‐rich basins country‐wide that also contain coalbed methane (CBM), an unconventional natural gas resource. Recent exploration of coal and CBM resources has also led to the discovery of rare, precious, and scattered metal minerals, including sandstone‐type U and Ga–Ge–Li. High‐grade and industrial‐value deposits have been discovered in the Ordos, Junggar, and other basins across China during exploration for coal resources. Application of coordinated exploration theories and techniques in multiple energy and coal‐associated ore deposits, such as coal and unconventional natural gas in coal, achieves efficient and practical exploration of natural resources. Based on the systematic study of accumulation and occurrence of coal and coal‐associated mineral resources in coal basins, the basic idea of coordinated exploration for coal and coal‐associated deposits is proposed, and multi‐targets and multi‐methods based on a coordinated exploration model of coal‐associated deposits is developed. Coordinated exploration expands the main exploration objective from coal seams to coal‐associated series, extending the exploration target from targeting coal only to coal‐associated deposits. Entrance times for exploration are decreased to realize coordinated exploration for coal, unconventional natural gas and syngenetic/associated mineral resources in coal by implementing a ‘one‐time approach’ —one time in and out of a coal seam to minimize disturbance and time needed for extraction. According to the differences of geological background in China's coal basins, four coordinated exploration model types, including co‐exploration of coal and coal‐associated unconventional natural gas, coal and solid minerals, coal and metal minerals, and coal with water resources are established. Other models discussed include a multi‐target coordinated exploration model for the combination of coal, coal‐associated gas, solid minerals, and metal minerals accordingly. The exploration techniques of coal and coal‐associated resources include regional geological investigation and research and synthetic application of other techniques including seismic surveys, drilling, logging, and geochemical exploration. Particularly, applying the ‘multi‐purpose drill hole’ or reworking coalfield drill holes into parameter wells, adding sample testing and logging wells, determining gas‐bearing layers by logging and gas content measurement, jointly measuring multiple logging parameters, sampling, and testing of coal‐strata help in the exploration and evaluation of coal resources, coal‐associated unconventional natural gas resources, and coal‐associated element minerals. Accordingly, a system of integrated Space–Air–Ground exploration techniques for coordinated exploration of coal and coal‐associated minerals is established. This includes high‐resolution, hyperspectral remote‐sensing technique, high‐precision geophysical exploration and fast, precise drilling, testing of experimental samples, as well as coordinated exploration and determination methods of multi‐target factors, multi‐exploration means, multi‐parameter configuration and optimization, big data fusions and interpretation techniques. In recent years, the application of this integrated system has brought significant breakthroughs in coal exploration in Inner Mongolia, Xinjiang and other provinces, discovering several large, ten‐billion‐ton coalfields, such as the Eastern Junggar and Tuha basins, and also in exploration and development of CBM from low‐rank coals in Fukang, Xinjiang, discovery the Daying U Deposit in Inner Mongolia, the Junggar Ultralarge Ga Deposit, Lincang, Yunnan, and the Wulantuga, Inner Mongolia, Ge‐bearing coal deposits, and the Pingshuo Ultralarge Li–Ge Deposit.

Methodology for Lost Gas Determination from Exploratory Coal Cores and Comparative Evaluation of the Accuracy of the Direct Method.

In the coal exploration of China, the commonly used direct method within 120 min has potential errors in lost gas calculation of deep coal seam for its complex geological conditions. The exploration of deep coal resources by drilling holes in Huainan of Eastern China offered an opportunity to starting research into developing a new method. A developed method with error analysis was constructed to estimate the lost gas using the total desorption process obtained from exploratory coal cores. The accuracy of the direct method was also evaluated comparatively. The result shows that the desorption curve of tested coal samples matches the fitted curve equation. Desorption temperature and the tectonic coal with associated pore characteristics significantly affect the variation of the adsorption characteristics and the estimation of lost gas. The direct method obviously underestimates the lost gas, and methodology using a new lost gas estimation procedure with additional residual gas allows for achieving relatively accurate results of the determination of gas content in coal seams. The calculated result of the new method is about 1.00–1.41 times that of the direct method. The error analysis of desorption results allowed us to determine the dependence between the time (retrieval time and desorption time) and determination method. The time used for desorption in the tank is allowed to extend to less than 400 min or more than 1000 min, which is very potentially important to accurately get the coalbed gas content for coring samples, especially deep exploratory cores for field application.

Isotopic signatures of major methane sources in the coal seam gas fields and adjacent agricultural districts, Queensland, Australia

Abstract. In regions where there are multiple sources of methane (CH4) in close proximity, it can be difficult to apportion the CH4 measured in the atmosphere to the appropriate sources. In the Surat Basin, Queensland, Australia, coal seam gas (CSG) developments are surrounded by cattle feedlots, grazing cattle, piggeries, coal mines, urban centres and natural sources of CH4. The characterization of carbon (δ13C) and hydrogen (δD) stable isotopic composition of CH4 can help distinguish between specific emitters of CH4. However, in Australia there is a paucity of data on the various isotopic signatures of the different source types. This research examines whether dual isotopic signatures of CH4 can be used to distinguish between sources of CH4 in the Surat Basin. We also highlight the benefits of sampling at nighttime. During two campaigns in 2018 and 2019, a mobile CH4 monitoring system was used to detect CH4 plumes. Sixteen plumes immediately downwind from known CH4 sources (or individual facilities) were sampled and analysed for their CH4 mole fraction and δ13CCH4 and δDCH4 signatures. The isotopic signatures of the CH4 sources were determined using the Keeling plot method. These new source signatures were then compared to values documented in reports and peer-reviewed journal articles. In the Surat Basin, CSG sources have δ13CCH4 signatures between −55.6 ‰ and −50.9 ‰ and δDCH4 signatures between −207.1 ‰ and −193.8 ‰. Emissions from an open-cut coal mine have δ13CCH4 and δDCH4 signatures of -60.0±0.6 ‰ and -209.7±1.8 ‰ respectively. Emissions from two ground seeps (abandoned coal exploration wells) have δ13CCH4 signatures of -59.9±0.3 ‰ and -60.5±0.2 ‰ and δDCH4 signatures of -185.0±3.1 ‰ and -190.2±1.4 ‰. A river seep had a δ13CCH4 signature of -61.2±1.4 ‰ and a δDCH4 signature of -225.1±2.9 ‰. Three dominant agricultural sources were analysed. The δ13CCH4 and δDCH4 signatures of a cattle feedlot are -62.9±1.3 ‰ and -310.5±4.6 ‰ respectively, grazing (pasture) cattle have δ13CCH4 and δDCH4 signatures of -59.7±1.0 ‰ and -290.5±3.1 ‰ respectively, and a piggery sampled had δ13CCH4 and δDCH4 signatures of -47.6±0.2 ‰ and -300.1±2.6 ‰ respectively, which reflects emissions from animal waste. An export abattoir (meat works and processing) had δ13CCH4 and δDCH4 signatures of -44.5±0.2 ‰ and -314.6±1.8 ‰ respectively. A plume from a wastewater treatment plant had δ13CCH4 and δDCH4 signatures of -47.6±0.2 ‰ and -177.3±2.3 ‰ respectively. In the Surat Basin, source attribution is possible when both δ13CCH4 and δDCH4 are measured for the key categories of CSG, cattle, waste from feedlots and piggeries, and water treatment plants. Under most field situations using δ13CCH4 alone will not enable clear source attribution. It is common in the Surat Basin for CSG and feedlot facilities to be co-located. Measurement of both δ13CCH4 and δDCH4 will assist in source apportionment where the plumes from two such sources are mixed.

Karotlu sondaj kulelerinde sorunlu formasyonlar için uygulanan çamur sistemleri

The two most important features of drilling rigs based on the core drilling principles are the drill set rotating at high speeds and the very precise spacing between the pipe and the well wall. Formation pieces that swell, flow into the well, spill or collapse during the drilling of problematic formations mix into the mud or narrow the annulus and cause well problems by restraining the rotation of the drill string and circulation. The spilled formation pieces cause an excessive solid material increase in the mud structure and due to the effect of centrifugal force, the solids adhere to the inner wall of the pipes near the surface and form a cake. Excessive cake thickness in the pipes obstruct the descent of the core barrel inner tube catcher into the well. During the removal of the inner tube, a vacuum occurs in the well due to the mud discharged from the rod and the problematic formations are poured into the annulus and block the core between the core barrel and the well wall. In this study, the performance of mud systems determined by trial and error method against the problems encountered in unconsolidated claystone, mudstone (shale), siltstone and sand - pebble stones in core coal exploration drillings in Çorum - Amasya region were evaluated. Monitoring and regular improvement of the rheological values of the mud compositions, changing the mud composition according to the well conditions, keeping the gel strength high and increasing its density with salt was found to play an important role in keeping the unconsolidated formations physically balanced. Salt mud also minimized the formation of cake in the pipe.

Neutralization and uptake of pollutant cations from acid mine drainage (amd) using limestones and zeolites in a pilot-scale passive treatment system

The exploration and beneficiation of mineral coal involve managing acid mine drainage (AMD), the acidic and metallic ion composition of which requires adequate treatment for disposal. In the present work, a passive pilot-scale AMD treatment system was developed using open channels of calcitic (CL-I and CL-II) and dolomitic (DL-I and DL-II) limestone beds and mixtures with natural zeolites (NZ) and functionalized zeolites (FZ). Investigated parameters include pH, electrical conductivity, total acidity, total alkalinity, and concentrations of aluminum, iron and manganese ions. DL-I, CL-II and mixtures of CL-II/NZ and CL-II/FZ increased pH levels from 3.3 to 7.9, 8.2, 7.9 and 7.6, respectively; increased total alkalinity levels from 0 mgCaCO3.L-1 to 20, 107, 42 and 34 mgCaCO3.L-1, respectively; and reduced total acidity levels by 95, 91, 90 and 90%, respectively. All beds promoted the removal of aluminum, iron and manganese ions, but the CL-II/FZ mixture was the most efficient due to both neutralization and a higher uptake of manganese ions (roughly 99%), which are pollutants that are typically difficult to remove. The study results reveal ways to transform passive treatment systems using limestone beds and unconventional materials such as zeolites, combine neutralization and adsorption mechanisms in the same operation, ensure a simple maintenance and operational system and improve the economic and environmental sustainability of related processes.

Suitability of Legacy Subsurface Data for Nascent Geoenergy Activities Onshore United Kingdom

The decarbonization of energy systems to achieve net zero carbon emissions will likely see the rapid development of carbon capture and storage, energy storage in the subsurface and geothermal energy projects. Subsurface data, in particular seismic reflection surveys and borehole data are vital for geoscientists and engineers to carry out comprehensive assessments of both the opportunities and risks for these developments. Their cost of acquisition means that such legacy data are commonly the only mechanism for site selection so biased data distribution must be accommodated. Here, legacy subsurface data from United Kingdom onshore hydrocarbon and coal exploration in the United Kingdom are collated and reviewed for their suitability for geoenergy activities. We provide a description of the spatial coverage and a chronology of the acquisition of key seismic reflection and borehole data, as well as examine data resolution and limitations. We discuss the implications of spatial variability in subsurface datasets and the associated subsurface uncertainty as this is vitally important to understanding the suitability of data for decision making. We examine societal aspects of data uncertainty and discuss that when the same data are used to communicate subsurface uncertainty and risk, the source of the data should also be considered, especially where data are not easily publicly accessible. Understanding the provenance and quality criteria of data are vitally important for future geoenergy activities and public confidence in subsurface activities. Finally, we ask should there be minimum data collection criterion, such as resolution requirements, ahead of subsurface activities with potentially significant impacts to the environment, economy, and society?

ON GEOTECHNOLOGICAL MODELING OF COKING COAL SINTERABILITY INDICES

He increase in the complexity of the structure of mined coking coal deposits and the variability of its quality in reserves is considered. It was noted that under such conditions, mining enterprises had to pay more attention to the management of coal consumer properties in order to achieve the quality level required by the market. It has been shown that digitalization of georesource and geotechnologies in the development of deposits contributes to obtaining a more complete and accurate view of production and marketing processes, increasing the efficiency of work in the exploration, production, enrichment and consumption of coal. The role and place of modeling of coal sinterability indices in seams and quality mapping in complex management systems of mining companies of South Yakutia are outlined. The feasibility of applying the results of 3D modeling, enhanced assessment of reserves taking into account their quality and geological conditions to customize the work of enterprises for various competitive stages of development of complex deposits.

Modeling and forecasting of principal minerals production

Although coal reserves are abundant in Pakistan, still share of gas and oil is about 65% in the energy mix. Pakistan, despite being a mineral-enriched country, is facing an alarming situation as its power generation is based on foreign exchange. The mineral sector of Pakistan is dominated by four principal minerals which are gas, oil, gypsum, and coal, while gypsum being a source of reclamation and poverty reduction. There is a strong need to analyze and forecast the production of these four principal minerals to cope up with emerging challenges. Data contains 114 observations from the period of July 2005 to December 2014, measured in terms of metric tonnes (MT). In parametric models, Box-Jenkins (B-J) methodology, a regression model with auto-regressive errors (ARAR), and Holt-Winter (HW) method are used to model. In nonparametric models, univariate singular spectrum analysis (SSA) and multivariate SSA (MSSA) modeling approach are applied. Data is split into train and test data in order to specify a suitable model for forecasting. Root Mean Square Error (RMSE), Mean Absolute Percentage Error, and Theil’s U statistic are utilized as the measure of accuracy. For gas and coal, HW model is a suitable model to forecast. For gypsum and oil, Auto-regressive Integrated Moving Average (Box Jenkins ARIMA) and MSSA provide more accurate predictions, respectively. The forecasts for gas and gypsum as compared to 2014 are expected to be approximately 11 % and 45 %, respectively, more in 2020. In 2020, the forecasts of oil are expected to be eight times more than in 2014. The production of coal in 2020 is expected to decrease 12 % than in 2014. There is a strong need to optimize the production of coal by providing incentives for exploration and mining. The stakeholders should make serious efforts to bring the production of coal at an optimum level such as by providing modern equipment and high incentives to promote coal mining and exploration.

Preliminary study as an exploration activity for estimating insitu coal density using the correlation of seismic downhole and geology drilling

The need for coal is increasing every year so that coal exploration activities need to be done to maintain the availability of these materials. Exploration activities generally use the correlation of geological method (analysis) and direct measurement using the geophysical method. One of the geophysical methods used is the downhole seismic method, to determine the quality of coal hardness through several seismic parameters, namely variations in the value of the initial wave velocity (Vp & Vs) and the wave travel time (Tp & Ts). This study aims to avoid mining land clearing and environmental destruction that are misplaced. This exploration activity is carried out at six measurement points. The results showed that the density of coal in the range 1.42 - 2.05 g/cm3, while coal that is feasible to be mined has a density of 1.81 - 2.05 g/cm3 with very soft rock to very hard rock classification.

Shallow seismic reflection survey for imaging deep-seated coal layer - Case study from Muara Enim coal

Indonesia has a great potential for deep-seated coal resources. To assist and support the deep-seated coal exploration, a shallow seismic reflection method is applicable for this purpose. This study has conducted a shallow seismic reflection method in Musi Banyuasin Regency, South Sumatera Province. The Muara Enim coal target varies from 100 to 500 meters from the surface. The thickness of the coal layer varies from 2 to 10.65 meters. This study uses 48 channels with 14 Hz single geophone and MiniSosie as the energy source. The receiver and source interval is 15 meters. This study uses a fixed receiver and moving source configuration. From the interpreted seismic section, this study identified a deep-seated coal layer target. These layers are Mangus, Burung, Benuang, Kebon and Benakat layers. A simple interpretation is analyzed by combining the seismic amplitude characteristics and the thickness of the coal layer from the borehole data. From the interpreted seismic section, deep-seated coal layer targets have strong amplitude characteristics and are continuous from southwest to the northeast with a down-dip of around 20-30°. This study helps to inform the operator companies who develop the utilization of deep-seated coal (coalbed methane, underground coal gasification and underground coal mining) about the effective and proper geophysical method for imaging deep-seated coal layer.

Szenes anyagok maximális átalakulási hőmérsékletének meghatározása Raman-spektroszkópiai mérésekkel: standardizálás és esettanulmány az Aggtelek–Rudabányai-hegységből

A mély diagenetikus – kisfokú metamorf üledékes kőzetek csúcshőmérsékletének meghatározását illit (Küblerindex) és klorit „kristályossági”, valamint vitrinit reflexiós értékek alapján nagy bizonytalanság terheli. A hőmérséklet pontosabb meghatározására az elmúlt időszakban egyre elterjedtebbé vált a szenes anyag szemcsék mérésén alapuló Raman-spektroszkópia. Jelen munka célja, hogy a szenes anyag Raman-spektroszkópia (RSCM) egyik módszerének alapjairól, valamint hazai alkalmazási lehetőségeiről adjon részletes, magyar nyelvű összefoglalást. A bemutatott módszer alkalmazásához elengedhetetlen egy ismert metamorf csúcshőmérsékletű referencia kőzetsorozat elemzése, amely az ismeretlen minták metamorf csúcshőmérsékletének meghatározásához szükséges kalibrációs görbe alapjául szolgál. Ez a referencia kőzetsorozat teszi lehetővé az egyes laboratóriumokban született eredmények összehasonlíthatóságát is. Munkánkban ismertetjük az ELTE TTK KKIC Raman-laboratóriumában mért referencia kőzetsorozat eredményeit, valamint az ez alapján létrehozott kalibrációs görbét. A módszer alkalmazhatóságát az Aggtelek–Rudabányai-hegység Telekesoldali Formációjának példáján mutatjuk be. Az öt mintán (négy fúrás, egy felszíni) elvégzett mérések alapján az összletre meghatározott metamorf csúcshőmérséklet 273 ± 10 °C-nak adódott, amely adat jelentősen pontosabb a korábban rendelkezésre álló illit- és klorit kristályossági, valamint vitrinit reflexiós értékek alapján becsült metamorf csúcshőmérsékleti értékeknél. A módszer kitűnően kiegészíti, valamint részben helyettesítheti a szénhidrogén-, illetve szén geológiában alkalmazott vitrinit reflexió méréseket.

Unconventional hydrocarbon resources in Tanzania: insight from geology and previous exploration of conventional resources

Unconventional oil and gas exploration has been developing rapidly in recent decades, while Tanzania has been paid very little consideration. This review aimed to infer these unconventional hydrocarbon resources in some basins, mostly the intracratonic Karoo basins and one coastal basin (Ruvu basin), from a piece of the very limited information available from the previous exploration of conventional resources. The presence of thick dark carbonaceous shales of Makarawe formation at Ruvu basin with TOC% 2.4–4.0% and a thickness between 107 and 698 m capped with non-porous oncolitic limestone and the gas shows encountered at an interval of 107 m of Makarawe shales at Makarawe-1 well makes Ruvu basin as important play for unconventional shale gas. The intracratonic Karoo basins have a thick deposit of Karoo sediments interbedded with coal deposits. Coal bedded methane has been encountered in a deep coal exploration borehole at Songwe-Kiwira coalfield. Geochemical analysis of outcrop samples from Namwele, Mbamba Bay, Njuga, and Mhukuru coalfields shows that the interbeds of coal-carbonaceous shales/mudstone have the rich organic matter of type III or both II and III and trace of oil on samples from Ketewaka and Ngaka coalfield make these sub-basins to be considered as potential plays for shale oil/gas. The presence of probable shale gas resources ranging from 50 to 200 trillion cubic feet at the Selous basin increases Karoo basins’ potentiality in exploring unconventional gas resources. In addition to the discovered conventional gas resource in offshore Tanzania, any unconventional resources will impact the country’s economic growth.

Late Permian palaeoenvironmental evolution of the Matinde Formation in the Muarádzi Sub-basin, Moatize-Minjova Basin, Mozambique

A multidisciplinary study involving lithofacies analysis, palynofacies, and palynology is presented for the Muarádzi Sub-basin. This sub-basin is part of the Moatize-Minjova Basin (MMB), an important Karoo aged coalfield in Mozambique.A total of 99 core samples from 3 coal exploration boreholes (DW11, DW21, and DW141) were analysed and all the successions were assigned a Lopingian age based on palynology. According to the data, in the Muarádzi Sub-basin, a vast lowland fluvial setting existed with floodplains and wetlands, in an area controlled by tectonic movements associated with a continental rifting phase. Typical vegetation of the Glossopteris Province is recorded in the palynological assemblages of this sub-basin, which allowed for the characterization of a flora dominated by glossopterids (Protohaploxypinus and Striatopodocarpites) and gymnosperm pollen (Alisporites). Other palynomorphs revealed the presence of gingkoales, ferns (Filicopsida), sphenopsids, and lycopsids in the area, indicating a typical lowland setting. Humid and warm climates, associated with higher CO2 atmospheric levels, promoted the growth of widespread vegetation that led to the development of the thick coal beds in anoxic to dysoxic depositional environments.

Evaluation of PT Adaro Indonesia's Corporate Social Responsibility (CSR) Program Policy, South Kalimantan, Indonesia

PT Adaro Indonesia is a mining company that conducts coal exploration and mining activities with the 3rd largest production in the world, one of the mining locations is located in Balangan Regency, South Kalimantan, Indonesia, Based on data released by the Central Statistics Agency for South Kalimantan in 2016 - 2019 economic growth balance in Balangan Regency. is the lowest economic growth among other regencies/cities, Bank Indonesia (BI) South Kalimantan region in 2019 the mining sector is still the prima donna of economic growth in the province of South Kalimantan, especially in Balangan Regency, if you look closely this shows that there are problems when viewed from one of the indicators of success community empowerment, theoretically it is stated that empowerment should not create dependence, but must be able to encourage the creation of creativity and community independence. This study aims to (1) analyze the policies of PT Adaro Indonesia's corporate social responsibility (CSR) program in Community Empowerment in Balangan Regency, (2) analyze the impact of PT Adaro Indonesia's corporate social responsibility (CSR) program on Community Empowerment in Balangan Regency and (3) Finding the right program policy evaluation model in community empowerment. The research method used in this study is a descriptive method with a qualitative approach. Determination of informants purposively (purposeful), the analysis technique used is data reduction, data display, verification. The results show that (1) PT Adaro Indonesia's corporate social responsibility (CSR) policy in empowering the people of Balangan Regency has not been implemented optimally, (2) the impact of PT Adaro Indonesia's CSR program has not fully provided a positive impact for the government and the people of Balangan Regency., (3) the program policy evaluation model that researchers offer starts from 1. Management Management, 2. Defined programs, 3. Target groups, 4. Implementation and 5. Impact. The advice given is that the authorities need to redesign the management of PT Adaro Indonesia's CSR funds.

Geocryological and Hydrogeological Conditions of the Western Part of Nordenskiold Land (Spitsbergen Archipelago)

This work summarizes the archived data of geocryological and hydrogeological conditions in the west of Nordenskiold Land on the Spitsbergen Archipelago. The historical data obtained in the Soviet period during coal exploration are reviewed together with the results of our own studies performed as part of the Russian Scientific Arctic Expedition on Spitsbergen (RAE-S) in 2016–2020. With respect to geocryology, the region is assigned to the zone of continuous permafrost. The thickness of rocks and sediments with temperatures below zero is about 100 m near the coast and increases to 540 m on watersheds. The mean annual ground temperature near the zero-amplitude depth varies from –3.6 to –2.2°C. Below this layer, the temperature curve in the top part of the section tends to deviate toward positive temperatures, reflecting the modern cycle of climate warming. From the hydrogeological point of view, the area belongs to the marginal zone of the West Spitsbergen cryoadartesian basin. Seawater intrusions near the coast form saline subpermafrost aquifers, including those with temperatures below zero, reflecting the seawater (sodium chloride) composition and hydraulic heads close to sea level. Fresh and slightly saline (sodium bicarbonate on the east coast of Gronfjorden and magnesium–calcium sulfate in gypsum-bearing deposits on the west coast) subpermafrost water with hydraulic heads reaching 100 m above sea level is fed by water-saturated ice in the deep layers of large glaciers.