Lignite Mine Research Articles

First fossil evidence of an extinct malvalean genus from India

ABSTRACT Hither, an extinct floral element of Florissantia Knowlton, unearthed from the early Eocene (~55–52 Ma) of the Gurha lignite mine, Rajasthan, western India, aids in highlighting the evolutionary significance of this angiosperm lineage in the Indian Cenozoic history. Comparison with fossil taxa from other regions supports the attribution to an extinct malvalean genus Florissantia. It is characterized by a transversely impressed, actinomorphic, gamosepalous flower with five rounded lobed sepals, each sepal fused at least 60% of its length, sinuses between sepal lobes shallowly incised and radiating reticulate venation. The occurrence of this extinct genus, previously known only from the Paleogene of North America and East Asia, is pertinent to the malvalean floristic diversification in India.

Enormous headward and gully erosion in a floodplain area reclaimed for open-cast lignite mining during the July 2021 flood in the Inde River valley (Western Germany)

BackgroundThe July flood 2021 at the mountain front of the Eifel-Ardennes Mountains and their foreland resulted in the flooding of the lignite mining area of Inden in Germany. The mining activities resulted in large-scale anthropogenic changes to the relief and fluvial system, leading to a landscape that is no longer adjusted to the recent process-response system. This paper concentrates on the Inde River, where lignite mining led to the relocation of a 5-km-long river section. The flood event resulted in the temporary avulsion of the Inde River into the former channel and, ultimately, in the flooding of the open-cast lignite mine Inden.ResultsThe flooding of the open-cast lignite mine Inden led to headwall erosion and enormous sediment mobilisation, mobilising more than half a million cubic metres of sediment within a few hours, forming a 700-m-long deeply incised channel cut. Thereby, the underlying bedrock, near-subsurface man-made structures, and former river channels influence the erosional processes to different degrees. Surface erosion is likely to be the decisive process, and subsurface erosion is likely to play a secondary role. In both cases, former channels and mill ditches were likely impacting the course of erosional processes.ConclusionsDuring high flood events open-cast mining sites in floodplains are endangered by enormous erosion and sediment transport within a short period of time (several hours). Understanding such complex erosion and depositional processes in open-cast mining areas could provide a blueprint for geomorphological processes and hazards in these anthropogenically shaped fluvial landscapes. Further, information on historic impact in the area is crucial to estimate potential risks.

Investigation of groundwater level change and its impact on slope stability in the Sector-E of Afsin-Elbistan Open-Pit Lignite Mine in Turkey

Investigation of groundwater level change and its impact on slope stability in the Sector-E of Afsin-Elbistan Open-Pit Lignite Mine in Turkey

Landscape in Transition, Heritage in the Making: A Research Agenda for Understanding Lusatia’s Post-mining Landscape as a Practice of Past Presencing

The region of Lusatia in Germany is characterised by a permanent state of uncertainty – as a consequence of decades of resettlements due to lignite mining as well as structural changes resulting from the German reunification. This article discusses an inclusive concept of post-mining landscapes and the presencing of their pasts in regional discourses, given that lignite mining in Lusatia mainly took place in the settlement area of the autochthonous minority of the Sorbs/Wends. Since the end of lignite mining is planned for 2038, historicizing perspectives such as a World Heritage initiative are becoming increasingly important, leading to a new conceptualisation of the post-mining landscape primarily as a practice of past presencing itself, which functions as a coping mechanism for facing up to new uncertainties, thereby emerging as a new action arena for the negotiation of regional identity, belonging and power structures.

Synsedimentary Compaction of Peat Under the Load of Alluvial System Sediments in the Most Basin (Czech Republic, Lower Miocene): From Weak Compaction to Strong Local Deformation of Clastics and Peat

Alluvial systems affected by peat layer compaction of a variable degree are studied all over the world, especially in areas of large river deltas and coastal plains. Ordinarily studied Holocene peat accumulations do not reach thicknesses of more than 6–10 m. This paper documents four ancient alluvial systems affected by peat compaction during the Lower Miocene in large exposures of open-cast lignite mines within the Most Basin, Czech Republic. Field observations and the study of 3000 borehole sections showed a clear dependence of the thickness and composition of the underlying peat on the scale of the accommodation space for loading by younger alluvial sediments. If the underlying partly compacted peat was tens to hundreds of meters in thickness, significant deformations of the peat appeared during its loading, leading up to the formation of growth faults. In such cases, missing parts of the coal seams were also observed below the alluvial systems. Especially borehole data showed that a linear correlation exists between the thickness of the alluvial sediments and the maximum instantaneous available compaction capacity of the underlying peat.

Analysis of the intensity of erosive processes and state of vegetation cover in the zone of influence of the Kolubara Mining Basin

Abstract Ensuring the quality protection of geospatial elements entails environmental control, a task unattainable without precise measurement results. This article aims to conduct a spatio-temporal analysis of soil degradation and vegetation status within the influence zone of the Kolubara Mining Basin in Serbia. Remote sensing is employed to assess vulnerability to erosion using the erosion potential method. A geographic information system environment is utilized to generate an erosion map, illustrating erosive processes across different time periods, particularly comparing the present situation (2022) to 1983. Results indicate that observed areas are experiencing erosion due to changes in land use. Furthermore, this study investigates the use of the normalized difference vegetation index to monitor vegetation cover changes from 1992 to 2022. The objective is to demonstrate that these methods effectively depict degradation levels and vegetation status in the area. This comprehensive overview provides insights into the changes occurring across the analyzed years. Such insights are crucial for informing future efforts to restore the region to its natural state prior to lignite mining.

Polish energy sector’s dependence on lignite mining: The process of transition

Polish energy sector’s dependence on lignite mining: The process of transition

Multi-Level Characterization of Lignite Mine Waste by the Integration of Wide Wavelength Range Infrared Spectroscopy

Both the mineralogy and geochemistry of coal mine waste presents environmental and social challenges while simultaneously offering the potential source for recovery of metals, including critical raw materials (CRMs). Assessing these challenges and opportunities requires effective waste management strategies and comprehensive material characterization. This study deals with the integration of analytical data obtained from various portable sensor technologies. Infrared reflection spectroscopy (covering a wide wavelength range of 0.4 to 15 µm), and geochemical x-ray fluorescence (XRF) were utilized to differentiate between samples belonging to various geological lithologies and quantify elements of interest. Therefore, we developed a methodological framework that encompasses data integration and machine learning techniques. The model developed using the infrared data predicts the Sr concentration with a model accuracy of R2 = 0.77 for the testing dataset; however, the model performances decreased for predicting other elements such as Pb, Zn, Y, and Th. Despite these limitations, the approach demonstrates better performance in discriminating materials based on both mineralogical and geochemical compositions. Overall, the developed methodology, enables rapid and in-situ determination of coal mine waste composition, providing insights into waste composition that are directly linked to potential environmental impact, and the possible recovery of economically valuable metals.

Carbon dioxide emissions from temperate reservoirs and pit lakes of different trophic states

The abundance of human-made inland waters, such as artificial ponds and reservoirs, has multiplied over the last decades. Compared to natural lakes, reservoirs and retention basins can exhibit a higher accumulation of organic carbon and a higher emission of greenhouse gases. Magnitude and dynamics of related emission fluxes are important to understand the role of inland waters in the global carbon cycle. However, origin and use of artificial waterbodies are diverse, and it is unclear whether current gas flux estimates adequately represent all important types and conditions of artificial inland waters. This study compares drivers of CO2 and CH4 emissions from two types of temperate artificial waters that are widespread in central Europe: reservoirs and artificial lakes in former open-pit lignite mines (pit lakes). We measured CO2 exchange at the water surface, calculated surface water CO2 from long-term DIC and pH data, and measured CO2 and CH4 concentrations throughout the water column. We found that an older, eutrophic pit lake showed seasonal variations in CO2 fluxes including uptake during summer and release during turnover, similar to three studied freshwater reservoirs. In contrast, reacidification and repeated addition of carbonate (liming) led to sustained CO2 supersaturation in a young, oligotrophic pit lake throughout the year, potentially making it a steady source of CO2 to the atmosphere. This implies that on an annual level, pH regulation and lake maturity largely determine whether pit lakes act as sources of CO2 (young, slightly acidic) or sinks of CO2 (older, neutral pH).

Estimates of late Early Cretaceous atmospheric CO2 from Mongolia based on stomatal and isotopic analysis of Pseudotorellia.

The Aptian-Albian (121.4-100.5 Ma) was a greenhouse period with global temperatures estimated as 10-15°C warmer than pre-industrial conditions, so it is surprising that the most reliable CO2 estimates from this time are <1400 ppm. This low CO2 during a warm period implies a very high Earth-system sensitivity in the range of 6 to 9°C per CO2 doubling between the Aptian-Albian and today. We applied a well-vetted paleo-CO2 proxy based on leaf gas-exchange principles (Franks model) to two Pseudotorellia species from three stratigraphically similar samples at the Tevshiin Govi lignite mine in central Mongolia (~119.7-100.5 Ma). Our median estimated CO2 concentration from the three respective samples was 2132, 2405, and 2770 ppm. The primary reason for the high estimated CO2 but with relatively large uncertainties is the very low stomatal density in both species, where small variations propagate to large changes in estimated CO2. Indeed, we found that at least 15 leaves are required before the aggregate estimated CO2 approaches that of the full data set. Our three CO2 estimates all exceeded 2000 ppm, translating to an Earth-system sensitivity (~3-5°C/CO2 doubling) that is more in keeping with the current understanding of the long-term climate system. Because of our large sample size, the directly measured inputs did not contribute much to the overall uncertainty in estimated CO2; instead, the inferred inputs were responsible for most of the overall uncertainty and thus should be scrutinized for their value choices.

Cross talk between PGPR and Casuarina junghuhniana on lignite mine soil

Cross talk between PGPR and Casuarina junghuhniana on lignite mine soil

The Coal Phase-Out in Germany and Its Regional Impact on Economic Worries

Market-driven closures of coal mines have typically been associated with negative economic consequences for the affected regions. In Germany, structural policy directed towards ameliorating the negative effects of hard coal decline in the Ruhr area lagged behind the onset of decline, caused major political conflicts, and has been variously criticized for its reactive character that failed to generate a positive image of the future. The phase-out of lignite coal in Germany, in contrast, is policy-driven and accompanied from the outset by compensatory and investment policies that strive to facilitate regional structural change proactively. Against this backdrop, we investigate how the policies of lignite coal phase-out initiated in 2018 and the accompanying public discourse affect the economic worries of individuals in the remaining three lignite coal mining areas in Germany. We focus on the period 2016–2021, using a longitudinal multilevel design based on regional and individual data from the German Socio-Economic Panel (GSOEP). Overall, probabilities of strong economic worries decrease throughout the observed period. Results show that subjective economic worries do not significantly differ between residents of lignite mining regions and those in the rest of the country. Further robustness analyses confirm that the coal phase-out policy has not increased economic uncertainties in the populations of German lignite mining regions. Based on our results, we discuss the need for future research on the effects of policy designs of clean energy transitions on subjective perceptions of the future.

Study of phosphorus status and sorption properties in reclaimed lignite mine soils under different age stands of Robinia pseudoacacia L. in Welzow, Germany

Study of phosphorus status and sorption properties in reclaimed lignite mine soils under different age stands of <scp><i>Robinia pseudoacacia</i></scp> L. in Welzow, Germany

Mechanical properties of soils in internal waste bank of lignite mines and their primary characteristics

The modern development of urban areas is related to, among others, the location of industrial facilities on the outskirts of cities. More and more often, commercial buildings are founded on areas that have not been used for construction so far. Such areas include, among others: reclaimed lignite mine banks in the Konin region. The man-made soil is a chaotic mixture of fragments of glacial tills and Pliocene clays, often exceeding 20 m in thickness, which is naturally consolidated over time. Due to the method of formation of the embankment, despite the fact that banks are made of natural soil, their strength and deformation characteristics clearly differ from those characteristic of lithologically similar soils deposited as a result of geological processes. In this case, the use of a standard test approach may overestimate the strength and stiffness of the soil. Due to the complex structure of the bank in-situ tests were used for geotechnical exploration: CPTU and FVT, as well as laboratory tests in a triaxial apparatus and an oedometer. The results were compared with the results of studies conducted in similar naturally deposited soils. The obtained results provide valuable geotechnical characteristics of the embankment soil, which in its large fragments is built of natural soil clasts. The obtained results indicate a relatively small change in the geotechnical properties of the soils incorporated into the embankment within individual clasts of the natural soil (on a local scale) and a clear deterioration in the scale of the entire embankment, treated as the impact zone of building structures.

Nutrient Accumulation in Silver Birch (Betula pendula Roth) Biomass in a Lignite Mining Area

The influence of lignite mining on vegetation constitutes a key issue due to the role of plants in restoring and maintaining the ecological balance of ecosystems. In this context, the identification of its impact on the functioning of silver birch (Betula pendula Roth) as a species often colonizing disturbed habitats takes on particular importance. Therefore, we aimed to determine the changes in nutrient content in silver birch overgrowing a spoil heap and in the vicinity of a fly ash settling pond and power plant. For this purpose, plant tissues (fine and coarse roots, stemwood, bark, coarse and fine branches, leaves) and soil samples (0–10, 10–20, 20–40, 20–40 cm deep) were examined. The basic soil characteristics were determined, along with the N, P, K, Ca, Mg, S, Fe, Mn, Cu, and Zn contents of the soil and plant samples. The soils varied in terms of soil pH and were poor in total organic carbon and other elements. The plant nutrient content varied strongly across the analyzed tissues, with the leaves usually containing the most and the stemwood the least nutrients. Statistical analysis indicated significant differences between the control vs spoil heap (particularly in Mn, S, and Mg) and the stand close to the settling pond (particularly in Ca, Mn, P, K, and S). We found that the chemical properties of the spoil heap and fly ash originating from the lignite mining operations are likely factors influencing nutrient accumulation in silver birch trees.

Biomining of ‘Heavy’ Metals and Lanthanides from Red Mud of a Former Lignite Mines by Sorption on Chitin

Biomining of ‘Heavy’ Metals and Lanthanides from Red Mud of a Former Lignite Mines by Sorption on Chitin

Influence of the dietary contribution of terrestrial insects to the condition factor of bleak Alburnus alburnus in a highly polluted lowland river.

Bleak Alburnus alburnus is a highly abundant but understudied fish species, and we know little about the trophic ecology of populations inhabiting rivers in central Europe. From an ecosystem perspective, this fish species is interesting as it is known to feed on surface insects, thereby linking the terrestrial with the aquatic habitat. In a previous study, we demonstrated that this flux is intensified, and dietary contribution of terrestrial insects is higher in fish inhabiting sections of the Spree River, Germany, that are polluted from iron oxides occurring from former lignite mining activities, and thus are characterized by lower abundances of aquatic insects. As terrestrial insects can be considered as food of lower quality (measured as long-chained polyunsaturated fatty acids, n-3 LC-PUFAs) compared to aquatic prey, it is reasonable to assume that the higher contribution of terrestrial insects is related to a lower body condition in fish. In this study, we explore the trophic ecology of riverine A. alburnus and their fitness consequences of feeding on terrestrial insects. We therefore modeled a terrestrial index from stable isotopes of hydrogen (δ2H) measured in the A. alburnus muscle tissue and compared individuals caught in locations upstream of a dam that were greatly influenced by iron oxides, with individuals caught in sections located downstream of a dam where passive remediation technologies are applied. The terrestrial index was significantly higher in A. alburnus caught in locations at high-iron concentrations, characterized by low abundances of aquatic prey, compared to A. alburnus caught in unpolluted habitats at low-iron concentrations. In contradiction to our hypothesis, the terrestrial index had no significant effect on the body condition of A. alburnus (measured as Fulton's condition factor K) in the sections downstream of the dam (i.e., at low-iron concentrations) and a significant positive, albeit weak, effect in sections upstream of the dam (i.e., at high-iron concentrations). However, the condition factor was generally lower in the high-iron section, potentially related to more direct effects of the iron oxide. We conclude that in A. alburnus, terrestrial insects can be considered as the less-favored food, unless the fish occur in environments where the aquatic food is of limited availability. Further research is needed to evaluate the direct and indirect effects, including the internal n-3 LC-PUFA synthesis as an adaption toward low-quality terrestrial prey on the fitness consequences of A. alburnus.

Probability distributions of geotechnical properties for heterogeneous lignite mine spoils

ABSTRACT During surface coal mining, large amounts of overburden waste materials, known as spoils, are excavated and dumped, creating massive heaps. The sustainable management of these areas is a global priority, but a comprehensive geotechnical characterization has not yet been achieved due to limited research on the spoils’ geotechnical properties. This study conducts an advanced statistical analysis of lignite mine spoil materials from a large heap in Greece to determine suitable probability distributions. Five distributions - normal, lognormal, Weibull (2 and 3 parameters), and Gamma - were evaluated, considering the high variability of spoil material properties. The lognormal and Weibull distributions were found to best fit most geotechnical parameters, except for cohesion, which showed an uncommon distribution. In some cases, the normal distribution can be used for a simplified analysis. The findings can guide the analysis of spoil materials, as advanced numerical and stochastic methods are essential for robust geotechnical design.

A freshwater ecosystem once existed in the Rajasthan desert: evidence from a fossil of the aquatic herb Nelumbo

Nelumbonaceae encompasses aquatic plant lineages that represent major components in the modern tropical wetland ecosystems of India. The group is characterized by its distinctive reproductive receptacle incorporating in situ fruitlets and vegetative organs that are well-represented in the fossil record. Unusually, though, no Nelumbo reproductive fossils have yet been identified from the Cenozoic of India. Here, we report the first such fossil reproductive organ from the aquatic perennial herb Nelumbo, which was recovered in the lower Eocene Palana Formation at the Gurha lignite mine in Rajasthan, western India. The fossil preserves an aggregate fruit with 28 indehiscent, apocarpous and globose to oblong fruitlets embedded within an accrescent receptacle, and a single small central cavity or apical remains of a stigma in each fruitlet. Comparisons with extant and extinct Nelumbo species support attribution to Nelumbo sp. Our unexpected discovery of a fully aquatic plant in the Rajasthan Basin during the early Eocene indicates that a freshwater ecosystem existed there ca 55 ± 10 million years ago; this contrasts starkly with the arid climatic conditions predominant in Rajasthan today. Raman Patel† [ ramanpatel2142@gmail.com ], Department of Geology, Hemvati Nandan Bahuguna Garhwal University, Srinagar, 246174 Uttarakhand, India Ashif Ali† [ aashifli0011@gmail.com ], Palaeobotany, Palynology, and Plant Evolution Laboratory, Department of Botany, Sidho-Kanho-Birsha University, Ranchi Road, Purulia-723104, India Rajendra Singh Rana [ rajendra.rana1@gmail.com ], Department of Geology, Hemvati Nandan Bahuguna Garhwal University, Srinagar, 246174 Uttarakhand, India Mahasin Ali Khan* [ khan.mahasinali@gmail.com ], Palaeobotany, Palynology, and Plant Evolution Laboratory, Department of Botany, Sidho-Kanho-Birsha University, Ranchi Road, Purulia-723104, India.

Sphagnoid spores as tracers of environmental and climatic changes in peatland habitats of the early Eocene

AbstractPeat mosses have been an important part of the lignite forming vegetation in the early Eocene of the Helmstedt Lignite Mining District. Three genera of Sphagnum-type spores can be distinguished: Tripunctisporis, Distancoraesporis and Sphagnumsporites. The distribution of these sphagnoid spores is traced through seven lignite seams including most of the known hyperthermal events from the PETM to the EECO. In general, Sphagnum-type spores increase in importance from base to top in each seam as a result of acidification and nutrient depletion during peat accumulation. The proportion of Tripunctisporis increases from Main Seam to Seam 6. The lower three seams are characterized by assemblages typical for coastal plain swamp forests including tree stumps and charcoal in distinct layers and lenses. The upper seams, in which Tripunctisporis is dominant and woody material is rare, are thin-bedded with charcoal in numerous thin drapes on bedding planes. The palynomorph assemblages here indicate a low growing mainly herbaceous vegetation typical of ombrogenous bogs. The change from topogenous swamp forests to open ombrogenous bogs takes place along with the hyperthermals of the early Eocene from the PETM to the EECO. The change from a swamp forest to a shrub forest in the middle of the Main Seam coincides with the isotope excursion of the PETM. Similar changes in other seams independent of thermal events indicate that thermal events merely amplify changes in vegetation, which are primarily imposed by edaphic constraints. It is rather the rapid accumulation of hyperthermals during the EECO that exerts sufficient environmental stress to fundamentally alter the peat forming vegetation. Graphical abstract