Pub Date : 2024-07-10DOI: 10.57035/journals/sdk.2024.e21.1272
Kristoffer Fowler, A. Forte
Assessing the relative contributions of tectonics and climate in orogenic systems and the stratigraphy preserved within their fringing basins has guided research for decades. Determining the role of these contributions is non-trivial and is difficult due to variations in both magnitude and period over which fluctuations in tectonics and climate occur, typically >105 – 7 years and <105 years, respectively. The Greater Caucasus is a young orogen that offers a unique opportunity to assess these critical roles through analysis of exposures of the foreland stratigraphy. Here, we synthesize available measured stratigraphic sections from within the Kura Fold-Thrust Belt and adjoining regions, creating multiple paleogeographic reconstructions for key regional chronostratigraphic stages, and then assessing the Kura Basin’s response time throughout these stages. We use basin response time as a proxy for whether tectonics or climate fluctuations could be preserved within the Kura Fold-Thrust Belt stratigraphy and, thus, what changes in depositional environments during those periods are more likely to reflect. In general, estimates of basin response times indicate that tectonic signals could be preserved throughout the Kura Basin during the deposition of the Productive Series. Climatic signals would likely be preserved during the deposition of the Akchagyl stage, although tectonics signals cannot be ruled out. During the Apsheronian stage, both tectonic and climate signals can be preserved. These results highlight that a foreland basin system can fluctuate between being able to record mixtures of tectonic and climatic signals during both different geologic stages and within the same stage across a foreland.
{"title":"Distinguishing climate and tectonic signals in the stratigraphy of the Kura Basin, the southeastern foreland of the Greater Caucasus","authors":"Kristoffer Fowler, A. Forte","doi":"10.57035/journals/sdk.2024.e21.1272","DOIUrl":"https://doi.org/10.57035/journals/sdk.2024.e21.1272","url":null,"abstract":"Assessing the relative contributions of tectonics and climate in orogenic systems and the stratigraphy preserved within their fringing basins has guided research for decades. Determining the role of these contributions is non-trivial and is difficult due to variations in both magnitude and period over which fluctuations in tectonics and climate occur, typically >105 – 7 years and <105 years, respectively. The Greater Caucasus is a young orogen that offers a unique opportunity to assess these critical roles through analysis of exposures of the foreland stratigraphy. Here, we synthesize available measured stratigraphic sections from within the Kura Fold-Thrust Belt and adjoining regions, creating multiple paleogeographic reconstructions for key regional chronostratigraphic stages, and then assessing the Kura Basin’s response time throughout these stages. We use basin response time as a proxy for whether tectonics or climate fluctuations could be preserved within the Kura Fold-Thrust Belt stratigraphy and, thus, what changes in depositional environments during those periods are more likely to reflect. In general, estimates of basin response times indicate that tectonic signals could be preserved throughout the Kura Basin during the deposition of the Productive Series. Climatic signals would likely be preserved during the deposition of the Akchagyl stage, although tectonics signals cannot be ruled out. During the Apsheronian stage, both tectonic and climate signals can be preserved. These results highlight that a foreland basin system can fluctuate between being able to record mixtures of tectonic and climatic signals during both different geologic stages and within the same stage across a foreland.","PeriodicalId":513481,"journal":{"name":"Sedimentologika","volume":"15 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141660833","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 : 2024-06-13DOI: 10.57035/journals/sdk.2024.e21.1318
Robin Hilderman, John MacDonald, Sammy Griffin, C. Slaymark, Joshua Einsle, Andrew Monaghan
Lithification of artificial ground comprising by-products of legacy iron and steel workings presents a range of opportunities including atmospheric carbon dioxide (CO2) storage. The natural environmental processes altering these waste sites can also pose challenges such as ecotoxic metal leaching, and so it is important to characterise these largely undocumented anthropogenically-derived rocks. This study documents the lithification mechanisms, as well as mineralogical and geochemical characteristics across a legacy coastal iron and steel slag deposit (in Warton, England). X-Ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) analysis of the slag deposit, as well as thermogravimetric analysis (TGA) of the cream-coloured material covering the deposit, shows lithification both on the top surface and the seaward side above the mean high-water mark (MHWM), which is the result of carbonate mineralisation. This process is driven by water weathering slag minerals (gehlenite, åkermanite, and pseudowollastonite), which release calcium (Ca). Ingassed and hydroxylated atmospheric CO2 reacts with the leached Ca to form calcite that is slightly to strongly depleted in 13C (δ13C values: -6.4 ‰ to -22.7 ‰), following partial dissolved inorganic carbonate (DIC) equilibrium. Calcium-silicate-hydrate (CSH) precipitation was responsible for lithifying the deposit where more frequent and abundant seawater washing prevents subsequent slag mineral dissolution and carbonate precipitation. This work shows that legacy iron and steel slag deposits are prone to lithification, particularly in coastal settings. This lithification can draw down atmospheric CO2 and has the potential to slow the release of toxic metals from CSH precipitation, enhancing the possibility for repurposing legacy industrial waste for CO2 storage and coastal defence applications.
{"title":"Heterogeneous lithification across a legacy coastal slag bank: the creation of new sedimentary rock from anthropogenic material","authors":"Robin Hilderman, John MacDonald, Sammy Griffin, C. Slaymark, Joshua Einsle, Andrew Monaghan","doi":"10.57035/journals/sdk.2024.e21.1318","DOIUrl":"https://doi.org/10.57035/journals/sdk.2024.e21.1318","url":null,"abstract":"Lithification of artificial ground comprising by-products of legacy iron and steel workings presents a range of opportunities including atmospheric carbon dioxide (CO2) storage. The natural environmental processes altering these waste sites can also pose challenges such as ecotoxic metal leaching, and so it is important to characterise these largely undocumented anthropogenically-derived rocks. This study documents the lithification mechanisms, as well as mineralogical and geochemical characteristics across a legacy coastal iron and steel slag deposit (in Warton, England). X-Ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) analysis of the slag deposit, as well as thermogravimetric analysis (TGA) of the cream-coloured material covering the deposit, shows lithification both on the top surface and the seaward side above the mean high-water mark (MHWM), which is the result of carbonate mineralisation. This process is driven by water weathering slag minerals (gehlenite, åkermanite, and pseudowollastonite), which release calcium (Ca). Ingassed and hydroxylated atmospheric CO2 reacts with the leached Ca to form calcite that is slightly to strongly depleted in 13C (δ13C values: -6.4 ‰ to -22.7 ‰), following partial dissolved inorganic carbonate (DIC) equilibrium. Calcium-silicate-hydrate (CSH) precipitation was responsible for lithifying the deposit where more frequent and abundant seawater washing prevents subsequent slag mineral dissolution and carbonate precipitation. This work shows that legacy iron and steel slag deposits are prone to lithification, particularly in coastal settings. This lithification can draw down atmospheric CO2 and has the potential to slow the release of toxic metals from CSH precipitation, enhancing the possibility for repurposing legacy industrial waste for CO2 storage and coastal defence applications.","PeriodicalId":513481,"journal":{"name":"Sedimentologika","volume":"67 43","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141346532","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 : 2024-05-06DOI: 10.57035/journals/sdk.2024.e21.1296
Christoph Daxer, Katleen Wils, Arne Ramisch, M. Strasser, J. Moernaut
In slowly deforming tectonic settings (e.g., European Alps), large earthquakes occur too infrequently to be adequately represented in instrumental and historical records. This leads to uncertainties and inaccuracies of seismic hazard estimations. To extend the seismic record, lacustrine paleoseismologists usually resort to the sedimentary archive of large lakes where earthquakes can be recorded as mass-transport deposits and associated turbidites. The imprint of seismic shaking is generally more subtle and poorly understood in small lakes (<2 km2) with small catchments and therefore such sediment-starved basins are often neglected for paleoseismology. However, these basins might harbour additional information about past earthquakes, thus constituting a valuable supplement to other paleoseismic data. Here, we present the 18 ka-long paleoseismic record of Klopeiner See, a small and rather shallow groundwater-fed lake in the Eastern European Alps. Reflection seismic profiles and sediment cores reveal that several large earthquakes led to extensive mass-wasting in early Late-Glacial times when sedimentation rates were very high (~10 mm/yr). In the Early and Middle Holocene, low sedimentation rates (~0.2-0.5 mm/yr) may have decreased the lake´s sensitivity for recording seismic shaking and no imprints were found for paleo-earthquakes inferred from other records in the region. A short succession of turbidites at ca. 3160 cal BP suggests a burst of strong paleoseismic activity. This may have caused permanent modifications of inflowing ground water systems, archived as a permanent shift in the geochemical signal of the sediment. Such a period of enhanced paleoseismic activity was also inferred from the nearby Lake Wörthersee, but it remains unclear whether these represent the same earthquakes or migrating paleoseismicity. This study highlights the unexpected potential and peculiarities of paleoseismology on small ground-water fed lakes.
在缓慢变形的构造环境中（如欧洲阿尔卑斯山），大地震发生的频率太低，无法在仪器和历史记录中得到充分体现。这导致了地震灾害估计的不确定性和不准确性。为了扩展地震记录，湖沼古地震学家通常会求助于大型湖泊的沉积档案，因为在这些湖泊中，地震可以被记录为物质迁移沉积和相关的浊积岩。在集水面积较小的小型湖泊（<2 平方公里）中，地震震痕通常更为细微，人们对其了解甚少，因此，这类沉积物匮乏的盆地在古地震学研究中往往被忽视。然而，这些盆地可能蕴藏着有关过去地震的更多信息，因此是对其他古地震数据的宝贵补充。在此，我们展示了 Klopeiner See 长达 18 ka 年的古地震记录，Klopeiner See 是东欧阿尔卑斯山脉的一个小型浅层地下水湖。反射地震剖面和沉积物岩芯显示，在沉积速率非常高（约 10 毫米/年）的晚冰期早期，几次大地震导致了大规模的物质流失。在全新世早期和中期，较低的沉积速率（约 0.2-0.5 毫米/年）可能降低了湖泊记录地震震动的灵敏度，因此没有发现根据该地区其他记录推断出的古地震印记。在大约公元前 3160 年，浊积岩出现了短暂的演替。约公元前 3160 年的浊积岩短时间的演替表明，曾发生过一次强烈的古地震活动。这可能导致流入的地下水系统发生永久性改变，沉积物的地球化学信号发生永久性转变。附近的沃瑟湖（Lake Wörthersee）也推断出了这样一个古地震活动增强的时期，但目前还不清楚这些活动是代表相同的地震，还是代表古地震活动的迁移。这项研究凸显了古地震学在小型地下水源湖泊中意想不到的潜力和特殊性。
{"title":"Contrasting sedimentary and long-lasting geochemical imprints of seismic shaking in a small, groundwater-fed lake basin (Klopeiner See, Eastern European Alps)","authors":"Christoph Daxer, Katleen Wils, Arne Ramisch, M. Strasser, J. Moernaut","doi":"10.57035/journals/sdk.2024.e21.1296","DOIUrl":"https://doi.org/10.57035/journals/sdk.2024.e21.1296","url":null,"abstract":"In slowly deforming tectonic settings (e.g., European Alps), large earthquakes occur too infrequently to be adequately represented in instrumental and historical records. This leads to uncertainties and inaccuracies of seismic hazard estimations. To extend the seismic record, lacustrine paleoseismologists usually resort to the sedimentary archive of large lakes where earthquakes can be recorded as mass-transport deposits and associated turbidites. The imprint of seismic shaking is generally more subtle and poorly understood in small lakes (<2 km2) with small catchments and therefore such sediment-starved basins are often neglected for paleoseismology. However, these basins might harbour additional information about past earthquakes, thus constituting a valuable supplement to other paleoseismic data. Here, we present the 18 ka-long paleoseismic record of Klopeiner See, a small and rather shallow groundwater-fed lake in the Eastern European Alps. Reflection seismic profiles and sediment cores reveal that several large earthquakes led to extensive mass-wasting in early Late-Glacial times when sedimentation rates were very high (~10 mm/yr). In the Early and Middle Holocene, low sedimentation rates (~0.2-0.5 mm/yr) may have decreased the lake´s sensitivity for recording seismic shaking and no imprints were found for paleo-earthquakes inferred from other records in the region. A short succession of turbidites at ca. 3160 cal BP suggests a burst of strong paleoseismic activity. This may have caused permanent modifications of inflowing ground water systems, archived as a permanent shift in the geochemical signal of the sediment. Such a period of enhanced paleoseismic activity was also inferred from the nearby Lake Wörthersee, but it remains unclear whether these represent the same earthquakes or migrating paleoseismicity. This study highlights the unexpected potential and peculiarities of paleoseismology on small ground-water fed lakes.","PeriodicalId":513481,"journal":{"name":"Sedimentologika","volume":"7 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141011238","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 : 2024-01-10DOI: 10.57035/journals/sdk.2024.e21.1067
E. Soutter, Ander Martínez-Doñate, I. Kane, M. Poyatos‐Moré, William Taylor, David M. Hodgson, M. J. Bouwmeester, Stephen Flint
Depositional and erosional bedforms can be used to reconstruct sedimentary processes and aid palaeoenvironmental interpretations. Using exhumed deep-marine strata in the Eocene Aínsa Basin, Spain, we document a 3-dimensional package of dunes, a rarely identified bedform in deep-marine environments. Our analysis shows that the dunes have curvilinear crests in planform, with smaller superimposed oblique dunes and ripples across the stoss sides. Beds containing these dunes have two main internal divisions: a lower inversely-graded (fine-to-coarse sandstone) and predominantly structureless division, and an upper coarse-grained sandstone division with well-developed cross-stratification, which is scoured and mantled with mudclasts and coarse-grains on the stoss-side. The rugose remnant relief of the bedforms controls the location of subsequent bedforms. Following recently reported direct measurements of natural turbidity currents, we interpret the basal division as recording deposition from the dense basal head of a high-velocity turbidity current, followed by the development of dunes beneath the more sustained but relatively high-velocity and unsteady flow body that reworked the initial sandy deposit into downstream migrating dunes and scours. These dune-forming beds have been identified in different deep-water environments in the Aínsa Basin stratigraphy, including channel overbank and channel mouth settings and scour-fills. These locations suggest that the dunes were intimately tied to high-velocity flows that bypassed through channel axes before expanded and depositing in less confined channel overbank or channel mouth settings. Preservation of these dunes in the Aínsa Basin was likely enhanced by tectonically-forced lateral migration of channels, which prevented cannibalisation of bypass-zones, in combination with high aggradation rates due to confinement, or periodic supply of flows from a particularly clay-poor source area. Where identified these dune-like bedforms are considered diagnostic of substantial sediment bypass downslope to deep-water basins.
{"title":"Exceptional preservation of three-dimensional dunes on an ancient deep-marine seafloor: implications for sedimentary processes and depositional environments","authors":"E. Soutter, Ander Martínez-Doñate, I. Kane, M. Poyatos‐Moré, William Taylor, David M. Hodgson, M. J. Bouwmeester, Stephen Flint","doi":"10.57035/journals/sdk.2024.e21.1067","DOIUrl":"https://doi.org/10.57035/journals/sdk.2024.e21.1067","url":null,"abstract":"Depositional and erosional bedforms can be used to reconstruct sedimentary processes and aid palaeoenvironmental interpretations. Using exhumed deep-marine strata in the Eocene Aínsa Basin, Spain, we document a 3-dimensional package of dunes, a rarely identified bedform in deep-marine environments. Our analysis shows that the dunes have curvilinear crests in planform, with smaller superimposed oblique dunes and ripples across the stoss sides. Beds containing these dunes have two main internal divisions: a lower inversely-graded (fine-to-coarse sandstone) and predominantly structureless division, and an upper coarse-grained sandstone division with well-developed cross-stratification, which is scoured and mantled with mudclasts and coarse-grains on the stoss-side. The rugose remnant relief of the bedforms controls the location of subsequent bedforms. Following recently reported direct measurements of natural turbidity currents, we interpret the basal division as recording deposition from the dense basal head of a high-velocity turbidity current, followed by the development of dunes beneath the more sustained but relatively high-velocity and unsteady flow body that reworked the initial sandy deposit into downstream migrating dunes and scours. These dune-forming beds have been identified in different deep-water environments in the Aínsa Basin stratigraphy, including channel overbank and channel mouth settings and scour-fills. These locations suggest that the dunes were intimately tied to high-velocity flows that bypassed through channel axes before expanded and depositing in less confined channel overbank or channel mouth settings. Preservation of these dunes in the Aínsa Basin was likely enhanced by tectonically-forced lateral migration of channels, which prevented cannibalisation of bypass-zones, in combination with high aggradation rates due to confinement, or periodic supply of flows from a particularly clay-poor source area. Where identified these dune-like bedforms are considered diagnostic of substantial sediment bypass downslope to deep-water basins.","PeriodicalId":513481,"journal":{"name":"Sedimentologika","volume":"37 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139441390","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 : 2024-01-08DOI: 10.57035/journals/sdk.2024.e21.1085
N. Sadid
In the Helmand/Sistan basin in southwest Afghanistan, aeolian sediment movement impacts the environment, irrigation canals, agriculture, and fluvial systems. The migration of large sand dunes into the Helmand and Arghandab rivers has a significant impact on the water resources providing livelihood for over three million people. A first step toward mitigating these impacts is to better understand sand dune migration. In this study, dune celerity and flux into the fluvial system are measured using PlanetScope Visual Ortho Scene satellite imagery. Two different time periods were used to quantify flux in five study sites of dune fields along 100 km of the Helmand River and 150 km of the Arghandab and Dori rivers. Results show diverse sand dune celerities with the fastest barchan dune movement south of Zaranj city. Sand dune celerity on the Helmand River right bank in the direction of flow is estimated to vary between 6.2 m/year to 103.1 m/year. The highest unit flux values of 250 m3/m/year occur in the lower Helmand basin. Much lower dune celerity values between 0.2 m/year to 2.9 m/year are calculated for the dune field on the left bank of the Arghandab and Dori rivers. The study also identifies the sensitive locations on the right bank of Helmand River in lower Helmand that may be used to plan sand dune stabilization measures such as mulching and Haloxylon species plantation that have been extensively practiced in the region.
{"title":"Sand dune migration and flux into the lower Helmand and Arghandab valleys","authors":"N. Sadid","doi":"10.57035/journals/sdk.2024.e21.1085","DOIUrl":"https://doi.org/10.57035/journals/sdk.2024.e21.1085","url":null,"abstract":"In the Helmand/Sistan basin in southwest Afghanistan, aeolian sediment movement impacts the environment, irrigation canals, agriculture, and fluvial systems. The migration of large sand dunes into the Helmand and Arghandab rivers has a significant impact on the water resources providing livelihood for over three million people. A first step toward mitigating these impacts is to better understand sand dune migration. In this study, dune celerity and flux into the fluvial system are measured using PlanetScope Visual Ortho Scene satellite imagery. Two different time periods were used to quantify flux in five study sites of dune fields along 100 km of the Helmand River and 150 km of the Arghandab and Dori rivers. Results show diverse sand dune celerities with the fastest barchan dune movement south of Zaranj city. Sand dune celerity on the Helmand River right bank in the direction of flow is estimated to vary between 6.2 m/year to 103.1 m/year. The highest unit flux values of 250 m3/m/year occur in the lower Helmand basin. Much lower dune celerity values between 0.2 m/year to 2.9 m/year are calculated for the dune field on the left bank of the Arghandab and Dori rivers. The study also identifies the sensitive locations on the right bank of Helmand River in lower Helmand that may be used to plan sand dune stabilization measures such as mulching and Haloxylon species plantation that have been extensively practiced in the region.","PeriodicalId":513481,"journal":{"name":"Sedimentologika","volume":"33 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139446576","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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