Pub Date : 2020-05-29DOI: 10.7494/geol.2020.46.1.17
Lilianna Chomiak
This paper focuses on the variations of lignite ash along selected sections and mining walls from three lignite opencast mines in central Poland. They are owned by the Konin Lignite Mine, where the first Mid-Polish lignite seam is being mined to produce electricity. Ash content in lignite is important because ash lowers the calorific value of the lignite. The results obtained are based on 266 samples of lignite collected from the Drzewce, Tomisławice, and Jóźwin IIB opencasts. All samples were tested according to ISO 1171 standard procedures, that is, they were first burned at a temperature of 850°C, then the ash content was determined on a dry basis (Ad), be-fore the basic statistical parameters were calculated. The studied lignite seam is characterised by a variable distribution pattern of ash both along selected vertical sections and lignite walls, as well as between the three open-casts. The ash content of individual samples ranged from 6.5 to 69.8 wt%, while the average content in opencast mines varied from 9.7 to 17.6 wt%. The coefficient of variation is large (80.23–96.33%) in the case of the Drzewce and Tomisławice, and low to average (14.53–37.75%) in the case of Jóźwin IIB. Significant ash enrichment of some beds is interpreted in this article as a consequence of floods occurring in a Mid-Miocene mire (backswamp), but also of chemical precipitation. When lignite is burned to generate electricity, a relatively large amount of ash is produced. Therefore, recognition of ash content in lignite, in addition to the chemical composition and phase of ash, is recommended to better protect the environment. At the first stage of protection, it can be best achieved by analysing field samples for ash content.
{"title":"Variation of lignite ash in vertical and horizontal sections of mining wallsin the Konin Lignite Mine, central Poland","authors":"Lilianna Chomiak","doi":"10.7494/geol.2020.46.1.17","DOIUrl":"https://doi.org/10.7494/geol.2020.46.1.17","url":null,"abstract":"This paper focuses on the variations of lignite ash along selected sections and mining walls from three lignite opencast mines in central Poland. They are owned by the Konin Lignite Mine, where the first Mid-Polish lignite seam is being mined to produce electricity. Ash content in lignite is important because ash lowers the calorific value of the lignite. The results obtained are based on 266 samples of lignite collected from the Drzewce, Tomisławice, and Jóźwin IIB opencasts. All samples were tested according to ISO 1171 standard procedures, that is, they were first burned at a temperature of 850°C, then the ash content was determined on a dry basis (Ad), be-fore the basic statistical parameters were calculated. The studied lignite seam is characterised by a variable distribution pattern of ash both along selected vertical sections and lignite walls, as well as between the three open-casts. The ash content of individual samples ranged from 6.5 to 69.8 wt%, while the average content in opencast mines varied from 9.7 to 17.6 wt%. The coefficient of variation is large (80.23–96.33%) in the case of the Drzewce and Tomisławice, and low to average (14.53–37.75%) in the case of Jóźwin IIB. Significant ash enrichment of some beds is interpreted in this article as a consequence of floods occurring in a Mid-Miocene mire (backswamp), but also of chemical precipitation. When lignite is burned to generate electricity, a relatively large amount of ash is produced. Therefore, recognition of ash content in lignite, in addition to the chemical composition and phase of ash, is recommended to better protect the environment. At the first stage of protection, it can be best achieved by analysing field samples for ash content.","PeriodicalId":12724,"journal":{"name":"Geology, Geophysics and Environment","volume":"40 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90707594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-29DOI: 10.7494/geol.2020.46.1.29
A. Tokarski, P. Strzelecki
Lower Cambrian Mt Currie conglomerate at Kata Tjuta bornhardts (Central Australia) bears numerous fractured clasts. Clast-cutting fractures are restricted to particular clasts, the matrix of the conglomerate is not fractured. The fractures are tectonic joints of two sets. The joints were formed due to either seismic or aseismic deformation. In the former case, the fractures may result from Early Paleozoic earthquakes.
{"title":"Fractured clasts in the Mt Currie Conglomerate at Kata Tjuta (Central Australia): evidence of Early Cambrian earthquakes?","authors":"A. Tokarski, P. Strzelecki","doi":"10.7494/geol.2020.46.1.29","DOIUrl":"https://doi.org/10.7494/geol.2020.46.1.29","url":null,"abstract":"Lower Cambrian Mt Currie conglomerate at Kata Tjuta bornhardts (Central Australia) bears numerous fractured clasts. Clast-cutting fractures are restricted to particular clasts, the matrix of the conglomerate is not fractured. The fractures are tectonic joints of two sets. The joints were formed due to either seismic or aseismic deformation. In the former case, the fractures may result from Early Paleozoic earthquakes.","PeriodicalId":12724,"journal":{"name":"Geology, Geophysics and Environment","volume":"24 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87300924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.7494/geol.2019.45.4.257
A. Akinsunmade, S. Tomecka-Suchoń, P. Pysz
In this paper, complex signal analyses of ground penetrating radar (GPR) field data over an area of farmland in Krakow were interpreted alongside the basic filtered field data. The farmland was simulated with var - ying degrees of soil compaction induced by tractor movement. The focus of the study was the delineation of in - herent characteristics of media through which the electromagnetic energy travelled. Fourteen GPR profiles were acquired from the area. The field data were subjected to pre- and post-processing prior to its the presentation and interpretation. Advance analysis operations on the field data which resorted in different attributes reveal more about the effects of the compaction on the soil than indicated by the basic filtered field data. Better resolution of subsurface layers boundary and lateral variation in the physical properties of the traversing media were well elu - cidated. The results have demonstrated that an advanced signal processing such as used in the study has ability to depict subtle characteristics of the propagating media.
{"title":"Complex analysis of GPR signalsfor the delineation of subsurface subtle features","authors":"A. Akinsunmade, S. Tomecka-Suchoń, P. Pysz","doi":"10.7494/geol.2019.45.4.257","DOIUrl":"https://doi.org/10.7494/geol.2019.45.4.257","url":null,"abstract":"In this paper, complex signal analyses of ground penetrating radar (GPR) field data over an area of farmland in Krakow were interpreted alongside the basic filtered field data. The farmland was simulated with var - ying degrees of soil compaction induced by tractor movement. The focus of the study was the delineation of in - herent characteristics of media through which the electromagnetic energy travelled. Fourteen GPR profiles were acquired from the area. The field data were subjected to pre- and post-processing prior to its the presentation and interpretation. Advance analysis operations on the field data which resorted in different attributes reveal more about the effects of the compaction on the soil than indicated by the basic filtered field data. Better resolution of subsurface layers boundary and lateral variation in the physical properties of the traversing media were well elu - cidated. The results have demonstrated that an advanced signal processing such as used in the study has ability to depict subtle characteristics of the propagating media.","PeriodicalId":12724,"journal":{"name":"Geology, Geophysics and Environment","volume":"18 1","pages":"257"},"PeriodicalIF":0.8,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83346970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.7494/geol.2019.45.4.305
M. Wendorff, A. Świąder
The Tsodilo Hills Group strata exposed in the Tsodilo Hills are an association of metaarenites, metaconglomerates, quartz-mica schists, sandstone, red siltstone and sedimentary breccia deposited on an open siliciclastic marine shelf between the Late alaeoproterozic and Late Mesoproterozoic, and outcropping in NW Botswana. The uccession is dominated by three micaceous quartzite units interlayered with subordinate lenses and wedges of other rock types. Facies gradients from S to N are expressed by: decreasing content of muscovite at all levels of metasediment organisation from thin wedge-shaped units to thick quartzite complexes, as well as a decrease in pebble content and increase in arenaceous matrix in some metaconglomerate beds, matching regional palaeotransport direction. Well-rounded pebbles of extrabasinal rocks are flat, suggesting redeposition from a beach environment. Lenticular conglomeratic bodies with erosional lower boundaries represent infills of local incisions in the sandy bottom sediments. The abundance of laterally discontinuous lithological units reflects shelf palaeotopography controlled and modified by deposition and migration of large bed forms, ranging from megaripple marks (or submarine dunes) to sand waves. Deposition was influenced by tides and two regressive events. The older regression resulted in a marker unit of tidal mudflat-related red-bed facies: mudstone, siltstone, channel-fill sandstone and sedimentary breccia. The second regression is indicated by a tabular conglomerate marker reflecting increased input of coarse terrigenous material.
{"title":"Lithostratigraphic classification of the Tsodilo Hills Group: a Palaeo- to Mesoproterozoic metasedimentary succession in NW Botswana","authors":"M. Wendorff, A. Świąder","doi":"10.7494/geol.2019.45.4.305","DOIUrl":"https://doi.org/10.7494/geol.2019.45.4.305","url":null,"abstract":"The Tsodilo Hills Group strata exposed in the Tsodilo Hills are an association of metaarenites, metaconglomerates, quartz-mica schists, sandstone, red siltstone and sedimentary breccia deposited on an open siliciclastic marine shelf between the Late alaeoproterozic and Late Mesoproterozoic, and outcropping in NW Botswana. The uccession is dominated by three micaceous quartzite units interlayered with subordinate lenses and wedges of other rock types. Facies gradients from S to N are expressed by: decreasing content of muscovite at all levels of metasediment organisation from thin wedge-shaped units to thick quartzite complexes, as well as a decrease in pebble content and increase in arenaceous matrix in some metaconglomerate beds, matching regional palaeotransport direction. Well-rounded pebbles of extrabasinal rocks are flat, suggesting redeposition from a beach environment. Lenticular conglomeratic bodies with erosional lower boundaries represent infills of local incisions in the sandy bottom sediments. The abundance of laterally discontinuous lithological units reflects shelf palaeotopography controlled and modified by deposition and migration of large bed forms, ranging from megaripple marks (or submarine dunes) to sand waves. Deposition was influenced by tides and two regressive events. The older regression resulted in a marker unit of tidal mudflat-related red-bed facies: mudstone, siltstone, channel-fill sandstone and sedimentary breccia. The second regression is indicated by a tabular conglomerate marker reflecting increased input of coarse terrigenous material.","PeriodicalId":12724,"journal":{"name":"Geology, Geophysics and Environment","volume":"4 4 1","pages":"305"},"PeriodicalIF":0.8,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83451907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.7494/geol.2019.45.4.269
B. Figarska-Warchoł, Marek Rembiś, Grażyna Stańczak
The work concerned the effects of the thermal treatment of diatomites from the Jawornik deposit (an example of the diatomites of the Leszczawka Member of the Polish Outer Carpathians). Five distinct lithological varieties were subjected to calcination at 600°C in ambient air. The thermal impact induced the following changes to the rocks. Their overall rock porosity increased, most distinctly in the initially softer varieties, and the internal pores of the siliceous frustules themselves usually became larger due to the initial melting of the silica phases. Most of the diatoms, quartz and feldspars cracked as a result of their brittle fracturing under compressive strain resulting from substantial and differing size changes of growing grains. Clay minerals were thermally transferred, changing their volume. The organic matter dispersed throughout the diatomites was partly oxidized and removed. At the same time, the structure of the rocks was strengthened, as confirmed by an increase in their microhardness. The microhardness of soft and porous diatomite varieties increased considerably on heating, but that of the hard and compact variety changed to a smaller degree. The increase is directly related to the content of the clay minerals. The impact of other mineral components was not detected. The calcination of lithologically diversified diatomites provided the mineral with raw material with deicing and antisliding properties. The technology of its production has been determined by the authors and submitted as a patent.
{"title":"The impact of calcination on changes in the physical and mechanical properties of the diatomites of the Leszczawka Member (the Outer Carpathians, Poland)","authors":"B. Figarska-Warchoł, Marek Rembiś, Grażyna Stańczak","doi":"10.7494/geol.2019.45.4.269","DOIUrl":"https://doi.org/10.7494/geol.2019.45.4.269","url":null,"abstract":"The work concerned the effects of the thermal treatment of diatomites from the Jawornik deposit (an example of the diatomites of the Leszczawka Member of the Polish Outer Carpathians). Five distinct lithological varieties were subjected to calcination at 600°C in ambient air. The thermal impact induced the following changes to the rocks. Their overall rock porosity increased, most distinctly in the initially softer varieties, and the internal pores of the siliceous frustules themselves usually became larger due to the initial melting of the silica phases. Most of the diatoms, quartz and feldspars cracked as a result of their brittle fracturing under compressive strain resulting from substantial and differing size changes of growing grains. Clay minerals were thermally transferred, changing their volume. The organic matter dispersed throughout the diatomites was partly oxidized and removed. At the same time, the structure of the rocks was strengthened, as confirmed by an increase in their microhardness. The microhardness of soft and porous diatomite varieties increased considerably on heating, but that of the hard and compact variety changed to a smaller degree. The increase is directly related to the content of the clay minerals. The impact of other mineral components was not detected. The calcination of lithologically diversified diatomites provided the mineral with raw material with deicing and antisliding properties. The technology of its production has been determined by the authors and submitted as a patent.","PeriodicalId":12724,"journal":{"name":"Geology, Geophysics and Environment","volume":"72 1","pages":"269"},"PeriodicalIF":0.8,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89682403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.7494/geol.2019.45.4.247
M. Strzelczyk, A. Steinhoff-Wrześniewska
The characteristics of Polish rural agglomerations indicate that only 32% of these areas are villages typified by compact buildings where the use of a collective sewage system is economically justified. In other areas, it is necessary to apply solutions that allow for the sewage utilization in place of their creation and safe discharge into the environment, e.g. in the form of home systems based on biological processes, e.g. in soil-plant systems. The purpose of the work was to determine the soil-plant efficiency of wastewater treatment with the use of so-called energy plants. The experiment was conducted in 2012–2014 in lysimeters at a depth of 130 cm and 100 cm in diameter. These were submerged in the ground, filled with sand clay and equipped with installations enabling the drain-age of gravity water in the form of lysimeter effluents. Two species of plants were used: Miscanthu giganteus and Sida hermaphrodita (L.) Rusby. They were irrigated with pre-treated domestic sewage (variant I – 1200 mm · year−1 and variant II – 1600 mm · year−1). For irrigation, sewage from a group of buildings inhabited by six families was used. Raw domestic sewage was discharged into the tank, consisting of four chambers, which constituted a relatively good level of pre-cleaning. For the irrigation of plants in the experiment, pre-treated sewage was used. In order to determine the effectiveness of wastewater treatment in the soil-plant environment, the concentrations of the following components were determined in the effluents: TSS, BOD5, COD, Ntot. The quantities of pollutants contained in the sewage were characterized by considerable variability, especially in relation to COD (390.6–1583.0 mg O2· dm−3) and Ntot (47.0–250.2 mg N · dm−3).
{"title":"Effectiveness of domestic rural wastewater treatment in soil-plant system","authors":"M. Strzelczyk, A. Steinhoff-Wrześniewska","doi":"10.7494/geol.2019.45.4.247","DOIUrl":"https://doi.org/10.7494/geol.2019.45.4.247","url":null,"abstract":"The characteristics of Polish rural agglomerations indicate that only 32% of these areas are villages typified by compact buildings where the use of a collective sewage system is economically justified. In other areas, it is necessary to apply solutions that allow for the sewage utilization in place of their creation and safe discharge into the environment, e.g. in the form of home systems based on biological processes, e.g. in soil-plant systems. The purpose of the work was to determine the soil-plant efficiency of wastewater treatment with the use of so-called energy plants. The experiment was conducted in 2012–2014 in lysimeters at a depth of 130 cm and 100 cm in diameter. These were submerged in the ground, filled with sand clay and equipped with installations enabling the drain-age of gravity water in the form of lysimeter effluents. Two species of plants were used: Miscanthu giganteus and Sida hermaphrodita (L.) Rusby. They were irrigated with pre-treated domestic sewage (variant I – 1200 mm · year−1 and variant II – 1600 mm · year−1). For irrigation, sewage from a group of buildings inhabited by six families was used. Raw domestic sewage was discharged into the tank, consisting of four chambers, which constituted a relatively good level of pre-cleaning. For the irrigation of plants in the experiment, pre-treated sewage was used. In order to determine the effectiveness of wastewater treatment in the soil-plant environment, the concentrations of the following components were determined in the effluents: TSS, BOD5, COD, Ntot. The quantities of pollutants contained in the sewage were characterized by considerable variability, especially in relation to COD (390.6–1583.0 mg O2· dm−3) and Ntot (47.0–250.2 mg N · dm−3).","PeriodicalId":12724,"journal":{"name":"Geology, Geophysics and Environment","volume":"31 3 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91258551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.7494/geol.2019.45.4.283
J. Barniak, Agnieszka Jureczko
Tree-ring analysis was used to investigate the impact of air pollution on forest stands in southern part of the Upper Silesia region of southern Poland. Four about 120 years old Scots pine stands located near Wodzislaw Śląski and Rybnik were selected for study and 20 increment core samples from each stand were taken. All study stands were selected based upon their considerable exposure to air and dust pollution. The results of dendrochronological analysis showed strong and significant reductions in tree ring growth especially during the period from 1960 to 1990. A significant number of trees with reductions (85%) was observed in two Scots pine stands both of which are directly exposed to air pollution from mine-owned coking plant and power and heating plants. Since 1990s the improved growth of these pines was clearly noted. A comparison for the period 1970 to 1990 for stands located west from the main emitters’ versus stands east and directly exposed found fewer trees with growth reductions (ca. 40%). At the beginning of the 21st century, a large number of trees in these western stands were observed with growth reductions between 50 and 60%. Probably, these trees were affected by air pollution from a nearby power plant located immediately across the border in the Czech Republic. Relationships between periods of severe reductions in ring width growth or missing rings were noted in a large percentage of pine trees in all four stands; these cross-stand relationships suggested common weather related impacts. Missing rings were noted in 1956, 1963, 1968, 1970, 1971, 1973, 1976 and 1979.
{"title":"Impact of air pollution on forest stands in the vicinity of Wodzisław Śląski and Rybnik, Poland","authors":"J. Barniak, Agnieszka Jureczko","doi":"10.7494/geol.2019.45.4.283","DOIUrl":"https://doi.org/10.7494/geol.2019.45.4.283","url":null,"abstract":"Tree-ring analysis was used to investigate the impact of air pollution on forest stands in southern part of the Upper Silesia region of southern Poland. Four about 120 years old Scots pine stands located near Wodzislaw Śląski and Rybnik were selected for study and 20 increment core samples from each stand were taken. All study stands were selected based upon their considerable exposure to air and dust pollution. The results of dendrochronological analysis showed strong and significant reductions in tree ring growth especially during the period from 1960 to 1990. A significant number of trees with reductions (85%) was observed in two Scots pine stands both of which are directly exposed to air pollution from mine-owned coking plant and power and heating plants. Since 1990s the improved growth of these pines was clearly noted. A comparison for the period 1970 to 1990 for stands located west from the main emitters’ versus stands east and directly exposed found fewer trees with growth reductions (ca. 40%). At the beginning of the 21st century, a large number of trees in these western stands were observed with growth reductions between 50 and 60%. Probably, these trees were affected by air pollution from a nearby power plant located immediately across the border in the Czech Republic. Relationships between periods of severe reductions in ring width growth or missing rings were noted in a large percentage of pine trees in all four stands; these cross-stand relationships suggested common weather related impacts. Missing rings were noted in 1956, 1963, 1968, 1970, 1971, 1973, 1976 and 1979.","PeriodicalId":12724,"journal":{"name":"Geology, Geophysics and Environment","volume":"1 1","pages":"283"},"PeriodicalIF":0.8,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79567730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-25DOI: 10.7494/geol.2019.45.4.291
T. Akana, O. Adeigbe
This study used repeat satellite imagery and Geographic Information System analysis to assess the planform dynamics along the length of the lower Niger River Valley from Onitsha city to the coast between 1985 and 2015. The aim is to understand the altered dynamics and its plausible causes in this data-poor region. Analyses revealed that the Niger River has undergone change corresponding to enhanced instability in terms of an increased rate of erosion. In the study area, a change was observed from 3.7% of deposition in the first 10 years (1985–1995) to 3.9% of erosion in the next 10 years (1995–2005) and 4.7% of erosion in the last 10 years (2005–2015). Total erosion over the 30-year period (1985–2015) in the delta was calculated on 4.8%. The river channel has migrated toward the east in the upper and lower reaches while the mid-section of the channel is migrating towards the west. The east river bank is observed to be more unstable compared to west bank line through the study period. The maximum shifts identified were 3.35 km of deposition in 10 years (1985–1995), 3.31 km of erosion in the next 10 years (1995–2005), and another substantial erosional shift of 3.35 km in the next 10 years (2005–2015). Avulsion rates gradually moved from −42.1 m∙year−1 (1985–2005, segment F) to 100.2 m∙year−1 (1985–1995, segment D), large deposition in the first 10 years. Total avulsion rates of the delta in the last 30 years (1985–2015) has pointed on erosion (−2.2 m∙year−1). The altered dynamics observed would likely threaten the future of the fragile lower river system environment and raise concerns for operators with infrastructure within the Niger Delta.
本研究使用重复卫星图像和地理信息系统分析来评估1985年至2015年间尼日尔河下游从奥尼沙市到海岸的平台动态。目的是了解这一数据贫乏地区的变化动态及其可能的原因。分析表明，尼日尔河在侵蚀率增加方面经历了与不稳定性增强相对应的变化。研究区前10年(1985-1995)沉积占3.7%，后10年(1995-2005)侵蚀占3.9%，后10年(2005-2015)侵蚀占4.7%。三角洲30年间(1985-2015)的总侵蚀率为4.8%。上、下游河道呈东移趋势，中游河道呈西移趋势。在研究期间，观察到东岸比西岸线更不稳定。结果表明:1985-1995年10年最大沉积位移为3.35 km, 1995-2005年最大侵蚀位移为3.31 km, 2005-2015年最大侵蚀位移为3.35 km。崩裂速率从- 42.1 m∙year - 1(1985-2005年，F段)逐渐增加到100.2 m∙year - 1(1985-1995年，D段)，前10年沉积量较大。在过去的30年(1985-2015)中，三角洲的总崩解速率指向侵蚀(- 2.2 m∙year - 1)。观察到的动态变化可能会威胁到脆弱的下游河流系统环境的未来，并引起尼日尔三角洲基础设施运营商的担忧。
{"title":"Channel characteristics and planform dynamics of the lower Niger River, Niger Delta Basin (1985–2015)","authors":"T. Akana, O. Adeigbe","doi":"10.7494/geol.2019.45.4.291","DOIUrl":"https://doi.org/10.7494/geol.2019.45.4.291","url":null,"abstract":"This study used repeat satellite imagery and Geographic Information System analysis to assess the planform dynamics along the length of the lower Niger River Valley from Onitsha city to the coast between 1985 and 2015. The aim is to understand the altered dynamics and its plausible causes in this data-poor region. Analyses revealed that the Niger River has undergone change corresponding to enhanced instability in terms of an increased rate of erosion. In the study area, a change was observed from 3.7% of deposition in the first 10 years (1985–1995) to 3.9% of erosion in the next 10 years (1995–2005) and 4.7% of erosion in the last 10 years (2005–2015). Total erosion over the 30-year period (1985–2015) in the delta was calculated on 4.8%. The river channel has migrated toward the east in the upper and lower reaches while the mid-section of the channel is migrating towards the west. The east river bank is observed to be more unstable compared to west bank line through the study period. The maximum shifts identified were 3.35 km of deposition in 10 years (1985–1995), 3.31 km of erosion in the next 10 years (1995–2005), and another substantial erosional shift of 3.35 km in the next 10 years (2005–2015). Avulsion rates gradually moved from −42.1 m∙year−1 (1985–2005, segment F) to 100.2 m∙year−1 (1985–1995, segment D), large deposition in the first 10 years. Total avulsion rates of the delta in the last 30 years (1985–2015) has pointed on erosion (−2.2 m∙year−1). The altered dynamics observed would likely threaten the future of the fragile lower river system environment and raise concerns for operators with infrastructure within the Niger Delta.","PeriodicalId":12724,"journal":{"name":"Geology, Geophysics and Environment","volume":"201 1 1","pages":"291"},"PeriodicalIF":0.8,"publicationDate":"2020-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83451821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.7494/geol.2020.46.3.189
M. Kaminski, A. Amao, Thomas F. Garrison, Flavia Fiorini, S. Magliveras, B. Tawabini, A. Waśkowska
A salt-marsh assemblage of agglutinated foraminifera was recovered from a salt marsh on the east side of Tubli Bay in eastern Bahrain. This locality is one of the last remaining patches of salt marsh on the east coast of Tubli Bay. The salt marsh is covered by a single marsh plant species, Arthrocnemum macrostachyum. Samples were collected from beneath the Arthrocnemum canopy in two transects beginning at the maximum landward extent of halophytic plants in the high marsh and extending to a tidal channel at the seaward side of the low marsh. A distinct elevation-related zonation in foraminifera is observed from the high marsh to the low marsh. The trochamminids Entzia macrescens and Trochammina inflata are characteristic of the high marsh, whereas Ammonia, Elphidium, Peneroplis and smaller miliolids become common in the middle part of the marsh transect. The tidal channel at the lower limit of the marsh contains an assemblage dominated by Ammonia, Elphidium, adult specimens of Peneroplis, and smaller miliolids, with Clavulina and Agglutinella as the only agglutinated taxa. Living specimens of Entzia and Trochammina were observed during the winter 2019–2020 sampling season, whereas samples collected in Autumn 2019 contained only dead specimens. One new species, ?Sigmoilina canisdementis sp. nov., is described herein. This is the first report of a live Entzia-dominated salt marsh assemblage in the Arabian Gulf region.
{"title":"An Entzia-dominated marsh-type agglutinated foraminiferal assemblage from a salt marsh in Tubli Bay, Bahrain","authors":"M. Kaminski, A. Amao, Thomas F. Garrison, Flavia Fiorini, S. Magliveras, B. Tawabini, A. Waśkowska","doi":"10.7494/geol.2020.46.3.189","DOIUrl":"https://doi.org/10.7494/geol.2020.46.3.189","url":null,"abstract":"A salt-marsh assemblage of agglutinated foraminifera was recovered from a salt marsh on the east side of Tubli Bay in eastern Bahrain. This locality is one of the last remaining patches of salt marsh on the east coast of Tubli Bay. The salt marsh is covered by a single marsh plant species, Arthrocnemum macrostachyum. Samples were collected from beneath the Arthrocnemum canopy in two transects beginning at the maximum landward extent of halophytic plants in the high marsh and extending to a tidal channel at the seaward side of the low marsh. A distinct elevation-related zonation in foraminifera is observed from the high marsh to the low marsh. The trochamminids Entzia macrescens and Trochammina inflata are characteristic of the high marsh, whereas Ammonia, Elphidium, Peneroplis and smaller miliolids become common in the middle part of the marsh transect. The tidal channel at the lower limit of the marsh contains an assemblage dominated by Ammonia, Elphidium, adult specimens of Peneroplis, and smaller miliolids, with Clavulina and Agglutinella as the only agglutinated taxa. Living specimens of Entzia and Trochammina were observed during the winter 2019–2020 sampling season, whereas samples collected in Autumn 2019 contained only dead specimens. One new species, ?Sigmoilina canisdementis sp. nov., is described herein. This is the first report of a live Entzia-dominated salt marsh assemblage in the Arabian Gulf region.","PeriodicalId":12724,"journal":{"name":"Geology, Geophysics and Environment","volume":"74 1","pages":"189"},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86308683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-22DOI: 10.7494/GEOL.2019.45.3.163
Sebastian Waszkiewicz, R. Alvarez, J. Jarzyna
This paper was made using geological and well logging data from the Cuban oilfield area and the Polish Carpathian Foredeep gas deposit to compare the interpretation process and underline similarities and differences between data analysis from two reservoir rocks of different lithology. Data from conventional hydrocarbon deposits, i.e. the Mesozoic Cuban carbonate formation and Miocene shaly-sandy sediments were processed and interpreted using Techlog (Schlumberger Co.) software. Selected approaches were used to determine the step by step volume of shale, total and effective porosity, water/hydrocarbon saturation (Quanti) and for the comprehensive interpretation of well logs (Quanti Elan). Brief characteristics of the carbonate and siliciclastic formations were presented to indicate that the interpretation methodology oriented to the determination of petrophysical properties depends strongly on the type of reservoir. Cross-plots were presented for primary mineral composition recognition, determination of m exponent and resistivity of formation water in the Archie equation. Effective intervals for the carbonate reservoir were calculated according to the Cumulative Hydrocarbon Column methodology. Finally, the results of the interpretation of well logs were presented as continuous curves of mineral composition, including shaliness, porosity and hydrocarbon saturation. The conclusions included recommendations for the effective comprehensive interpretation of well logs in the carbonate and siliciclastic reservoirs.
{"title":"Results of the comprehensive interpretation of well logs in carbonate and siliciclastic rocks – similarities and differences in the case studies of selected formations","authors":"Sebastian Waszkiewicz, R. Alvarez, J. Jarzyna","doi":"10.7494/GEOL.2019.45.3.163","DOIUrl":"https://doi.org/10.7494/GEOL.2019.45.3.163","url":null,"abstract":"This paper was made using geological and well logging data from the Cuban oilfield area and the Polish Carpathian Foredeep gas deposit to compare the interpretation process and underline similarities and differences between data analysis from two reservoir rocks of different lithology. Data from conventional hydrocarbon deposits, i.e. the Mesozoic Cuban carbonate formation and Miocene shaly-sandy sediments were processed and interpreted using Techlog (Schlumberger Co.) software. Selected approaches were used to determine the step by step volume of shale, total and effective porosity, water/hydrocarbon saturation (Quanti) and for the comprehensive interpretation of well logs (Quanti Elan). Brief characteristics of the carbonate and siliciclastic formations were presented to indicate that the interpretation methodology oriented to the determination of petrophysical properties depends strongly on the type of reservoir. Cross-plots were presented for primary mineral composition recognition, determination of m exponent and resistivity of formation water in the Archie equation. Effective intervals for the carbonate reservoir were calculated according to the Cumulative Hydrocarbon Column methodology. Finally, the results of the interpretation of well logs were presented as continuous curves of mineral composition, including shaliness, porosity and hydrocarbon saturation. The conclusions included recommendations for the effective comprehensive interpretation of well logs in the carbonate and siliciclastic reservoirs.","PeriodicalId":12724,"journal":{"name":"Geology, Geophysics and Environment","volume":"141 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86250933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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