Pub Date : 2025-02-10DOI: 10.1016/j.sedgeo.2025.106833
Szymon Świątek, Małgorzata Pisarska-Jamroży
Seismically liquefaction-induced soft-sediment deformation structures are key to understanding the geological history of earthquakes and sedimentary environments. These evidences usually have been associated with high-magnitude seismic events, above 5. However, the precise thresholds and mechanisms, especially for lower-magnitude earthquakes, remained unclear. This study aims to address this gap by experimentally investigating the development of deformation structures under controlled laboratory conditions. Using three sediment types arranged in five sequences, the sediments were subjected to low-magnitude seismic vibrations. Developed liquefaction features such as clastic volcanoes, pseudonodules, flame structures, and load casts were measured by a novel morphometric analysis to quantify their size and shape. The findings revealed that even at a magnitude of ∼3.5, liquefaction and deformation structures can occur, especially in high water-saturated fine-grained sediments. These results provide new insights into the thresholds of seismically-induced liquefaction and highlight the importance of considering lower-magnitude events in seismic risk assessments, offering significant implications for the study of sedimentary processes and earthquake-related deformation.
{"title":"Seismogenic liquefaction with M ∼ 3.5 in fine-grained sediments: An experimental approach","authors":"Szymon Świątek, Małgorzata Pisarska-Jamroży","doi":"10.1016/j.sedgeo.2025.106833","DOIUrl":"10.1016/j.sedgeo.2025.106833","url":null,"abstract":"<div><div>Seismically liquefaction-induced soft-sediment deformation structures are key to understanding the geological history of earthquakes and sedimentary environments. These evidences usually have been associated with high-magnitude seismic events, above 5. However, the precise thresholds and mechanisms, especially for lower-magnitude earthquakes, remained unclear. This study aims to address this gap by experimentally investigating the development of deformation structures under controlled laboratory conditions. Using three sediment types arranged in five sequences, the sediments were subjected to low-magnitude seismic vibrations. Developed liquefaction features such as clastic volcanoes, pseudonodules, flame structures, and load casts were measured by a novel morphometric analysis to quantify their size and shape. The findings revealed that even at a magnitude of ∼3.5, liquefaction and deformation structures can occur, especially in high water-saturated fine-grained sediments. These results provide new insights into the thresholds of seismically-induced liquefaction and highlight the importance of considering lower-magnitude events in seismic risk assessments, offering significant implications for the study of sedimentary processes and earthquake-related deformation.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"478 ","pages":"Article 106833"},"PeriodicalIF":2.7,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-03DOI: 10.1016/j.sedgeo.2025.106825
Ming-wei Ma , Jia-wen Zhou , Xing-guo Yang , Yi-hui Liang , Tao Yang , Hai-mei Liao
This study explores the impact of granular materials with varying moisture contents and particle sizes, as well as block materials with different volumes and layer strengths, on landslide fragmentation, motion, and deposit. The experimental results show that as particle size increases, the maximum dam height (Hmax) and width (Wmax) increase, while the minimum dam height (Hmin) decreases, indicating an improvement in the stability of landslide dams. Larger particle sizes are less sensitive to changes in moisture content. Additionally, moisture content inhibits Wmax, with mixed particle-size materials showing a greater reduction compared to single particle-size materials. As Wmax increases, the maximum dam length (Lmax) decreases exponentially. Sliding time (Ts), deposition time (Td), and total time (T) decrease as particle size increases. For mixed particle-size materials, a more continuous particle size distribution further reduces Ts, Td, and T. Block material experiments show that with increasing block volume, Wmax, Lmax, and Hmax increase significantly, with corresponding increases in Ts, Td, and T. When the strength of the lower layer material decreases, Wmax and Hmax decrease, while Ts, Td, and T increase. Conversely, when the lower layer material strength increases, the opposite effect is observed. Frictional energy loss (Ef) is the primary energy loss pathway, with both total energy loss and Ef decreasing with increasing particle size. Localized energy losses are mainly due to terrain collisions, independent of moisture content.
{"title":"Experiments study on landslide motion and damming deposit for particle and block materials with different mechanical properties","authors":"Ming-wei Ma , Jia-wen Zhou , Xing-guo Yang , Yi-hui Liang , Tao Yang , Hai-mei Liao","doi":"10.1016/j.sedgeo.2025.106825","DOIUrl":"10.1016/j.sedgeo.2025.106825","url":null,"abstract":"<div><div>This study explores the impact of granular materials with varying moisture contents and particle sizes, as well as block materials with different volumes and layer strengths, on landslide fragmentation, motion, and deposit. The experimental results show that as particle size increases, the maximum dam height (<em>H</em><sub><em>max</em></sub>) and width (<em>W</em><sub><em>max</em></sub>) increase, while the minimum dam height (<em>H</em><sub><em>min</em></sub>) decreases, indicating an improvement in the stability of landslide dams. Larger particle sizes are less sensitive to changes in moisture content. Additionally, moisture content inhibits <em>W</em><sub><em>max</em></sub>, with mixed particle-size materials showing a greater reduction compared to single particle-size materials. As <em>W</em><sub><em>max</em></sub> increases, the maximum dam length (<em>L</em><sub><em>max</em></sub>) decreases exponentially. Sliding time (<em>T</em><sub><em>s</em></sub>), deposition time (<em>T</em><sub><em>d</em></sub>), and total time (<em>T</em>) decrease as particle size increases. For mixed particle-size materials, a more continuous particle size distribution further reduces <em>T</em><sub><em>s</em></sub>, <em>T</em><sub><em>d</em></sub>, and <em>T</em>. Block material experiments show that with increasing block volume, <em>W</em><sub><em>max</em></sub>, <em>L</em><sub><em>max</em></sub>, and <em>H</em><sub><em>max</em></sub> increase significantly, with corresponding increases in <em>T</em><sub><em>s</em></sub><em>, T</em><sub><em>d</em></sub>, and <em>T</em>. When the strength of the lower layer material decreases, <em>W</em><sub><em>max</em></sub> and <em>H</em><sub><em>max</em></sub> decrease, while <em>T</em><sub><em>s</em></sub><em>, T</em><sub><em>d</em></sub>, and <em>T</em> increase. Conversely, when the lower layer material strength increases, the opposite effect is observed. Frictional energy loss (<em>E</em><sub><em>f</em></sub>) is the primary energy loss pathway, with both total energy loss and <em>E</em><sub><em>f</em></sub> decreasing with increasing particle size. Localized energy losses are mainly due to terrain collisions, independent of moisture content.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"478 ","pages":"Article 106825"},"PeriodicalIF":2.7,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143336963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-03DOI: 10.1016/j.sedgeo.2025.106824
Se Hyun Cho, Suk-Joo Choh
The depositional record of epeiric platforms is typically interrupted by unconformities, reflecting repetition of sedimentation and non-deposition. The Ordovician epeiric platform on the North China includes a Lower to Middle Ordovician unconformity, and this study documented early Darriwilian re-inundation events in the Makgol Formation from four sections over a distance of 25 km in the Taebaek area, eastern North China Craton.
The Makgol Formation mainly comprises micritic limestone with subordinate laminite and grainy facies, exhibiting subaerial exposure features in its lower part, and is interpreted as a micrite-dominated inner platform deposit. The re-inundation pattern is characterized by accumulation of metre-scale peritidal and subtidal cycles, which show an overall deepening upward trend, marked by a decrease in exposure features and an increase in subtidal cycles. However, this deepening trend was not gradual and occurred stepwise. Seven cycle sets, each consisting of one to six cycles, are described along with eight correlated key flooding surfaces. Each flooding event caused retreat of the facies belt to varying degrees, while cycles within cycle sets exhibited shallowing upward stacking patterns. These deepening upward trends are similar to punctuated transgressions observed in continental shelves, which suggest the applicability of the sequence stratigraphic concept from continental margins to inner epeiric platforms.
Lateral variations in the number of cycles between sections are recognised in seven intervals, four of which are interpreted as the result from erosion and non-deposition associated with subaerial exposure features. This finding suggests the incompleteness in transgressive deposits in inner epeiric platform conditions and highlights the importance of identifying missing cycles for the interpretation of stacking pattern and origin of metre-scale cycles.
{"title":"Re-inundation of the North China epeiric platform: A cyclic peritidal succession above a Lower–Middle Ordovician unconformity in southern Korea","authors":"Se Hyun Cho, Suk-Joo Choh","doi":"10.1016/j.sedgeo.2025.106824","DOIUrl":"10.1016/j.sedgeo.2025.106824","url":null,"abstract":"<div><div>The depositional record of epeiric platforms is typically interrupted by unconformities, reflecting repetition of sedimentation and non-deposition. The Ordovician epeiric platform on the North China includes a Lower to Middle Ordovician unconformity, and this study documented early Darriwilian re-inundation events in the Makgol Formation from four sections over a distance of 25 km in the Taebaek area, eastern North China Craton.</div><div>The Makgol Formation mainly comprises micritic limestone with subordinate laminite and grainy facies, exhibiting subaerial exposure features in its lower part, and is interpreted as a micrite-dominated inner platform deposit. The re-inundation pattern is characterized by accumulation of metre-scale peritidal and subtidal cycles, which show an overall deepening upward trend, marked by a decrease in exposure features and an increase in subtidal cycles. However, this deepening trend was not gradual and occurred stepwise. Seven cycle sets, each consisting of one to six cycles, are described along with eight correlated key flooding surfaces. Each flooding event caused retreat of the facies belt to varying degrees, while cycles within cycle sets exhibited shallowing upward stacking patterns. These deepening upward trends are similar to punctuated transgressions observed in continental shelves, which suggest the applicability of the sequence stratigraphic concept from continental margins to inner epeiric platforms.</div><div>Lateral variations in the number of cycles between sections are recognised in seven intervals, four of which are interpreted as the result from erosion and non-deposition associated with subaerial exposure features. This finding suggests the incompleteness in transgressive deposits in inner epeiric platform conditions and highlights the importance of identifying missing cycles for the interpretation of stacking pattern and origin of metre-scale cycles.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"478 ","pages":"Article 106824"},"PeriodicalIF":2.7,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143360437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coastal depositional systems can be classified into transgressive and regressive systems, but their dynamics in relation to multi-segment sea level change remains largely unknown. In this study, we examined five sediment cores and 57 radiocarbon dates from the Wakayama Plain, western Japan. We have elucidated that the maximum flooding surface is dated at 7.6 cal kyr BP (8 ka), and the depositional system changed from a wave-dominated estuary to a wave-dominated delta at around 4 ka. This two-step change in the coastal depositional system can be explained by the decreasing in the rate of sea-level rise at 8 ka and the onset of sea-level fall at 4 ka, respectively. The coastal dynamics of the Wakayama Plain suggests that in areas where the mid-Holocene sea-level was higher than present sea levels, the sediment stacking pattern was controlled by the “rate” of sea-level rise, and the change in the geometry of the depositional system was controlled by the “height” of sea level.
{"title":"Coastal dynamics and sea-level change at 4 ka: A case study from the Wakayama Plain, Japan","authors":"Susumu Tanabe , Kanata Kobayashi , Toshiaki Irizuki , Akira Tsujimoto , Rei Nakashima , Yuki Haneda , Yoshiro Ishihara","doi":"10.1016/j.sedgeo.2025.106807","DOIUrl":"10.1016/j.sedgeo.2025.106807","url":null,"abstract":"<div><div>Coastal depositional systems can be classified into transgressive and regressive systems, but their dynamics in relation to multi-segment sea level change remains largely unknown. In this study, we examined five sediment cores and 57 radiocarbon dates from the Wakayama Plain, western Japan. We have elucidated that the maximum flooding surface is dated at 7.6 cal kyr BP (8 ka), and the depositional system changed from a wave-dominated estuary to a wave-dominated delta at around 4 ka. This two-step change in the coastal depositional system can be explained by the decreasing in the rate of sea-level rise at 8 ka and the onset of sea-level fall at 4 ka, respectively. The coastal dynamics of the Wakayama Plain suggests that in areas where the mid-Holocene sea-level was higher than present sea levels, the sediment stacking pattern was controlled by the “rate” of sea-level rise, and the change in the geometry of the depositional system was controlled by the “height” of sea level.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"476 ","pages":"Article 106807"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.sedgeo.2024.106801
Chao FU , Yuhong XIE , Hui WANG , Wei XU
<div><div>Significant volumes of sediment are deposited in deep-sea regions via turbidite channel systems, which function as critical conduits for the transport of sediment from shelf environments to the abyssal plain; concurrently, complex sedimentary processes—such as erosion, incision, and sedimentation—play an integral role in the development of diverse architectural features. In particular, the head area of slope-parallel submarine turbidite channel systems is marked by significant sediment transport, yet the rapidly changing topography has limited our understanding of their architectural stacking patterns. In this study, we selected the head area of the Central Canyon Area (CCA) in the Qiongdongnan Basin (QDNB) as a case study and constructed various patterns of turbidite channel system architecture along the turbidity flow direction. Based on >200 m of core samples, we identified nine lithofacies and determined the transition patterns of turbidite flows from coarse-grained equilibrium flow, fine-grained equilibrium flow, depositional flow, and erosion flow. Furthermore, utilizing high-resolution 3D seismic data, we measured the geomorphological parameters of the channel systems, including the static aspect ratio, cross-sectional asymmetry, angles of channel-complex growth trajectories, and stratigraphic mobility numbers. By applying an empirical formula that correlates turbidite channel system morphology with layer-averaged flow velocity, we calculated the corresponding Froude numbers. Finally, we reconstructed the evolution of the turbidite channel system architecture in different hierarchies.① In the initial depositional stage, coarse-grained and fine-grained equilibrium flows developed. The turbidite channel system complex presented high aspect ratios and asymmetry values in upstream depocentre areas, transitioning to lower aspect ratios in midstream regions while maintaining high asymmetry. This architecture is characterized by steady vertical accretion types, with the predominant filling types being layer-filled, cut-stack, and interbedded mass transport deposits (MTDs). ② During the rapid accumulation stage, a shift to lower aspect ratios and asymmetry values occurs, revealing diverse turbidite channel systems, primarily lateral accretion types with layered filling, lateral products, and cut-stack patterns dominating the channel stacks. ③ In the reworking MTD stage, a sharp change in the aspect ratio signals a dominance of lateral accretion-type channel systems interbedded with MTDs.</div><div>Furthermore, we identify key factors influencing the architecture of turbidite channel system stack patterns across different stages and speculate on deposition patterns in slope-parallel submarine channel heads. Statistical analysis of the morphological parameters revealed that during the initial deposition and rapid accumulation stages, the topographic slope angle and turbidity currents were the primary influences on channel accumulation.
{"title":"Architectures of the turbidite channel in the head area of a slope-parallel directional submarine turbidite channel system: A case study of the Central Canyon Area, Qiongdongnan Basin, South China Sea","authors":"Chao FU , Yuhong XIE , Hui WANG , Wei XU","doi":"10.1016/j.sedgeo.2024.106801","DOIUrl":"10.1016/j.sedgeo.2024.106801","url":null,"abstract":"<div><div>Significant volumes of sediment are deposited in deep-sea regions via turbidite channel systems, which function as critical conduits for the transport of sediment from shelf environments to the abyssal plain; concurrently, complex sedimentary processes—such as erosion, incision, and sedimentation—play an integral role in the development of diverse architectural features. In particular, the head area of slope-parallel submarine turbidite channel systems is marked by significant sediment transport, yet the rapidly changing topography has limited our understanding of their architectural stacking patterns. In this study, we selected the head area of the Central Canyon Area (CCA) in the Qiongdongnan Basin (QDNB) as a case study and constructed various patterns of turbidite channel system architecture along the turbidity flow direction. Based on >200 m of core samples, we identified nine lithofacies and determined the transition patterns of turbidite flows from coarse-grained equilibrium flow, fine-grained equilibrium flow, depositional flow, and erosion flow. Furthermore, utilizing high-resolution 3D seismic data, we measured the geomorphological parameters of the channel systems, including the static aspect ratio, cross-sectional asymmetry, angles of channel-complex growth trajectories, and stratigraphic mobility numbers. By applying an empirical formula that correlates turbidite channel system morphology with layer-averaged flow velocity, we calculated the corresponding Froude numbers. Finally, we reconstructed the evolution of the turbidite channel system architecture in different hierarchies.① In the initial depositional stage, coarse-grained and fine-grained equilibrium flows developed. The turbidite channel system complex presented high aspect ratios and asymmetry values in upstream depocentre areas, transitioning to lower aspect ratios in midstream regions while maintaining high asymmetry. This architecture is characterized by steady vertical accretion types, with the predominant filling types being layer-filled, cut-stack, and interbedded mass transport deposits (MTDs). ② During the rapid accumulation stage, a shift to lower aspect ratios and asymmetry values occurs, revealing diverse turbidite channel systems, primarily lateral accretion types with layered filling, lateral products, and cut-stack patterns dominating the channel stacks. ③ In the reworking MTD stage, a sharp change in the aspect ratio signals a dominance of lateral accretion-type channel systems interbedded with MTDs.</div><div>Furthermore, we identify key factors influencing the architecture of turbidite channel system stack patterns across different stages and speculate on deposition patterns in slope-parallel submarine channel heads. Statistical analysis of the morphological parameters revealed that during the initial deposition and rapid accumulation stages, the topographic slope angle and turbidity currents were the primary influences on channel accumulation. ","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"476 ","pages":"Article 106801"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.sedgeo.2024.106783
John T. Haynes , Rafael A. Villanueva , Richard M. Robinet , Stephen A. Leslie , Achim D. Herrmann
<div><div>An increase in accumulation of phosphate-enriched sediment occurred in several areas of Earth's oceans during the later Ordovician, suggesting that some fundamental change (s) in seawater and/or pore water chemistry were taking place, either syndepositionally or during early diagenesis. One hypothesis is that widespread cooling of the water column led to this increase, but another is that the increase could have been forced primarily by changes in seawater chemistry that accompanied an influx of siliciclastic sediments associated with tectonically driven subsidence. Here, we report on findings from study of the upper ~30 m of the >200 m of Middle and Late Ordovician strata exposed near Tidwell Hollow, Blount County, Alabama, and what the results suggest about the competing hypotheses. This Ordovician sequence, deposited along the southeastern margin of Laurentia during the initial (Blountian) stage of the Taconic Orogeny, records the transition from a restricted peritidal carbonate shelf environment (the “Black River lithofacies”) into a more normal marine carbonate environment (the “Trenton lithofacies”). In particular, the younger carbonate strata are notable for their measurably higher amounts of secondary phosphate minerals. This stratigraphic interval is also well-constrained chronostratigraphically by the presence of the Deicke and Millbrig K-bentonite beds (altered volcanic tephra layers), thus it is ideal for a focused geochemical, petrographic, and stratigraphic investigation of the increased phosphate content of a specific Upper Ordovician sequence. Analyses of bulk rock samples and of extracted collophane grains (via x-ray fluorescence, XRF, and in-situ laser ablation inductively coupled plasma mass spectrometer, ICPMS) suggest that phosphogenesis in these strata was episodic rather than slow and steady, with a depositional pattern of abrupt increases followed by abrupt declines. Observed trace element changes in the 12 m to 18 m sample interval include the occurrence of elevated Th/U ratios (maximum of 5.7) accompanied by Y/Ho ratios that range from 27 (base) to 51 (top). We attribute these changes to increasing silicate influx into the basin and an accompanying increase in available Fe, which would preferentially scavenge MREEs and then release them to the pore waters leading to MREE enrichment, which we also observe in this interval. In a rapidly subsiding basin, MREE enrichment could have resulted from initial restriction of bottom water circulation followed by gradually more open marine conditions. Some allochems and textures that are more characteristic of the older Black River lithofacies than the younger Trenton lithofacies (e.g. framework grains of calcareous green algae and Type 1 and Type 2 oncoids, fenestral lime mudstones, and associated small framestones of <em>Tetradium</em> sp. buildups) persist in relative abundance upsection into the ~10 m interval of strata above the Millbrig K-bentonite Bed, and this pe
{"title":"Rapid subsidence as a driver of phosphate deposition in the later Ordovician: Case study from the Alabama Appalachians","authors":"John T. Haynes , Rafael A. Villanueva , Richard M. Robinet , Stephen A. Leslie , Achim D. Herrmann","doi":"10.1016/j.sedgeo.2024.106783","DOIUrl":"10.1016/j.sedgeo.2024.106783","url":null,"abstract":"<div><div>An increase in accumulation of phosphate-enriched sediment occurred in several areas of Earth's oceans during the later Ordovician, suggesting that some fundamental change (s) in seawater and/or pore water chemistry were taking place, either syndepositionally or during early diagenesis. One hypothesis is that widespread cooling of the water column led to this increase, but another is that the increase could have been forced primarily by changes in seawater chemistry that accompanied an influx of siliciclastic sediments associated with tectonically driven subsidence. Here, we report on findings from study of the upper ~30 m of the >200 m of Middle and Late Ordovician strata exposed near Tidwell Hollow, Blount County, Alabama, and what the results suggest about the competing hypotheses. This Ordovician sequence, deposited along the southeastern margin of Laurentia during the initial (Blountian) stage of the Taconic Orogeny, records the transition from a restricted peritidal carbonate shelf environment (the “Black River lithofacies”) into a more normal marine carbonate environment (the “Trenton lithofacies”). In particular, the younger carbonate strata are notable for their measurably higher amounts of secondary phosphate minerals. This stratigraphic interval is also well-constrained chronostratigraphically by the presence of the Deicke and Millbrig K-bentonite beds (altered volcanic tephra layers), thus it is ideal for a focused geochemical, petrographic, and stratigraphic investigation of the increased phosphate content of a specific Upper Ordovician sequence. Analyses of bulk rock samples and of extracted collophane grains (via x-ray fluorescence, XRF, and in-situ laser ablation inductively coupled plasma mass spectrometer, ICPMS) suggest that phosphogenesis in these strata was episodic rather than slow and steady, with a depositional pattern of abrupt increases followed by abrupt declines. Observed trace element changes in the 12 m to 18 m sample interval include the occurrence of elevated Th/U ratios (maximum of 5.7) accompanied by Y/Ho ratios that range from 27 (base) to 51 (top). We attribute these changes to increasing silicate influx into the basin and an accompanying increase in available Fe, which would preferentially scavenge MREEs and then release them to the pore waters leading to MREE enrichment, which we also observe in this interval. In a rapidly subsiding basin, MREE enrichment could have resulted from initial restriction of bottom water circulation followed by gradually more open marine conditions. Some allochems and textures that are more characteristic of the older Black River lithofacies than the younger Trenton lithofacies (e.g. framework grains of calcareous green algae and Type 1 and Type 2 oncoids, fenestral lime mudstones, and associated small framestones of <em>Tetradium</em> sp. buildups) persist in relative abundance upsection into the ~10 m interval of strata above the Millbrig K-bentonite Bed, and this pe","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"476 ","pages":"Article 106783"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.sedgeo.2024.106803
Edoardo Perri , Mario Borrelli , Maurizio Ponte
Despite laboratory reproduced microbially induced Ca‑carbonate precipitation is currently used for various sustainable bio-engineering applications, an inevitable environmental impact because of the waste materials and chemicals involved in lab activities still occurs. Here is presented a new and alternative net-0 experimental procedure to obtain a Ca‑carbonate bio-cement, developed in a natural fluvial laboratory (Parmenta stream) where microbial-mediated calcite precipitates, forming typical tufa deposits. The experiment consisted in the treating of a common multimineral sand (0,355–1 mm in grain size) with the stream flowing water for 4 months, associated with a parallel control monitoring of the precipitation process. During this time interval, thanks to the development and mediation of the microbial biofilm community, calcite precipitated with a variable daily rate from 0,49 to 2,94 μm/day, showing typical hierarchical nano- to micro-crystalline morphological features. This process brought to the gradual formation of a calcite bio-cement around the sand particles, starting from scattered tens of μm-size crystal aggregates to continuous crusts up to ca. 200 μm thick. The internal friction angle of the sand showed a total increase of ca. 20 % (i.e. 5,9° from 28,6° to 34,5°), with the major growth of ca. 16 % (i.e. 4,8° from 28,6° to 33,4°) after just 1 month; this indicates that just few amounts of new precipitates are enough to obtain the 80 % of such increase, most probably due to the roughness rise of the grains. Whereas, the cohesion showed a constant reduction trough time up to a total of ca. -64 % (from 0,17 Kg/cm2 to 0,06 Kg/cm2); this probably due to a reduction of the grains' specific surface on which the electrostatic attractions act.
{"title":"Net-0 experimental procedure to obtain Ca‑carbonate bio-cement via microbially induced precipitation in a fluvial natural lab","authors":"Edoardo Perri , Mario Borrelli , Maurizio Ponte","doi":"10.1016/j.sedgeo.2024.106803","DOIUrl":"10.1016/j.sedgeo.2024.106803","url":null,"abstract":"<div><div>Despite laboratory reproduced microbially induced Ca‑carbonate precipitation is currently used for various sustainable bio-engineering applications, an inevitable environmental impact because of the waste materials and chemicals involved in lab activities still occurs. Here is presented a new and alternative net-0 experimental procedure to obtain a Ca‑carbonate bio-cement, developed in a natural fluvial laboratory (Parmenta stream) where microbial-mediated calcite precipitates, forming typical tufa deposits. The experiment consisted in the treating of a common multimineral sand (0,355–1 mm in grain size) with the stream flowing water for 4 months, associated with a parallel control monitoring of the precipitation process. During this time interval, thanks to the development and mediation of the microbial biofilm community, calcite precipitated with a variable daily rate from 0,49 to 2,94 μm/day, showing typical hierarchical nano- to micro-crystalline morphological features. This process brought to the gradual formation of a calcite bio-cement around the sand particles, starting from scattered tens of μm-size crystal aggregates to continuous crusts up to ca. 200 μm thick. The internal friction angle of the sand showed a total increase of ca. 20 % (i.e. 5,9° from 28,6° to 34,5°), with the major growth of ca. 16 % (i.e. 4,8° from 28,6° to 33,4°) after just 1 month; this indicates that just few amounts of new precipitates are enough to obtain the 80 % of such increase, most probably due to the roughness rise of the grains. Whereas, the cohesion showed a constant reduction trough time up to a total of ca. -64 % (from 0,17 Kg/cm<sup>2</sup> to 0,06 Kg/cm<sup>2</sup>); this probably due to a reduction of the grains' specific surface on which the electrostatic attractions act.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"476 ","pages":"Article 106803"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.sedgeo.2024.106805
Lihui Liu , Sen Wang , Zhanjie Xu , Tianjiao Yu , Joan S. Esterle , Suzanne D. Golding , Yunfei Xi , Qinfu Liu
Sedimentary pyrite is ubiquitous in coal measures and occurs with different crystal morphologies and geochemical characteristics that are typically employed to infer the bottom seawater microenvironment and diagenetic stages. In this study, representative pyrite with four distinct crystal morphologies were identified in Carboniferous coal gangue in North China. The crystal structure, microscopic morphology, in-situ sulfur isotope content, and distribution of pyrite crystals were comprehensively analyzed using polarizing microscopy, X-ray diffraction, scanning electron microscope, and nanoscale secondary ion mass spectrometry to better understand the diagenetic evolution of these Carboniferous rocks. The varying morphologies and δ34S values of pyrite closely correlate to the crystal growth pattern, sulfur source, and precipitation mechanism. Euhedral granular pyrite and framboidal pyrite have relatively small particle sizes and negative δ34S values (average − 6.59 ‰ and − 36.62 ‰) and are interpreted to have formed through the reduction of sulfate in a brackish lagoon from the syn-depositional stage to the early diagenetic stage. In contrast, massive pyrite and cell-filling pyrite exhibit slightly larger particle size and positive δ34S values (average + 9.39 ‰ and + 10.53 ‰), which suggest formation in the diagenetic stage under the action of microbial sulfate reduction. The geochemical characteristics recorded in the microscale pyrites indicate that the primary sulfur source is seawater sulfate where the wide range of pyrite sulfur isotope values reflects substrate depletion effects in an increasingly closed system. This research highlights the vital relationship between grain shape and the mechanism of sedimentary pyrite formation in the coal-forming environment. Thus, different pyrite mineralization processes in the world can be identified, and the environment of crystal growth understood by in-situ sulfur isotope analysis.
{"title":"In-situ sulfur isotope characteristic and genesis of sedimentary pyrite with varying crystal morphologies in coal-bearing strata in North China","authors":"Lihui Liu , Sen Wang , Zhanjie Xu , Tianjiao Yu , Joan S. Esterle , Suzanne D. Golding , Yunfei Xi , Qinfu Liu","doi":"10.1016/j.sedgeo.2024.106805","DOIUrl":"10.1016/j.sedgeo.2024.106805","url":null,"abstract":"<div><div>Sedimentary pyrite is ubiquitous in coal measures and occurs with different crystal morphologies and geochemical characteristics that are typically employed to infer the bottom seawater microenvironment and diagenetic stages. In this study, representative pyrite with four distinct crystal morphologies were identified in Carboniferous coal gangue in North China. The crystal structure, microscopic morphology, <em>in-situ</em> sulfur isotope content, and distribution of pyrite crystals were comprehensively analyzed using polarizing microscopy, X-ray diffraction, scanning electron microscope, and nanoscale secondary ion mass spectrometry to better understand the diagenetic evolution of these Carboniferous rocks. The varying morphologies and δ<sup>34</sup>S values of pyrite closely correlate to the crystal growth pattern, sulfur source, and precipitation mechanism. Euhedral granular pyrite and framboidal pyrite have relatively small particle sizes and negative δ<sup>34</sup>S values (average − 6.59 ‰ and − 36.62 ‰) and are interpreted to have formed through the reduction of sulfate in a brackish lagoon from the <em>syn</em>-depositional stage to the early diagenetic stage. In contrast, massive pyrite and cell-filling pyrite exhibit slightly larger particle size and positive δ<sup>34</sup>S values (average + 9.39 ‰ and + 10.53 ‰), which suggest formation in the diagenetic stage under the action of microbial sulfate reduction. The geochemical characteristics recorded in the microscale pyrites indicate that the primary sulfur source is seawater sulfate where the wide range of pyrite sulfur isotope values reflects substrate depletion effects in an increasingly closed system. This research highlights the vital relationship between grain shape and the mechanism of sedimentary pyrite formation in the coal-forming environment. Thus, different pyrite mineralization processes in the world can be identified, and the environment of crystal growth understood by <em>in-situ</em> sulfur isotope analysis.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"476 ","pages":"Article 106805"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.sedgeo.2024.106785
Mara R. Diaz , Kelly Bergman , Peter K. Swart , Gregor P. Eberli
Fecal pellets are key components of the biological carbon pump and a source of nutrients. When cohesively bound and cemented, they become the most abundant non-skeletal grains in shallow-water carbonates and an important nucleus for ooid formation. Herein, we describe the mineralization processes contributing to pellet cementation using scanning electron microscopy in conjunction with stable isotope and mineralogical analyses of the bulk sediments on Great Bahama Bank, known for its abundance of peloids and fecal pellets. Results show biogenic signatures consistent with the initial stages of organomineralization. These include, curved-tubular filaments and bacilli bacteria associated with extracellular polymeric substances (EPS); fibrils of EPS binding aragonite needles; and the coexistence of decayed EPS with amorphous calcium carbonate that once it develops, coalesces and crystalizes into aragonite. While δ13Cinorg do not show large variations, slightly higher values are observed in areas where pellets are indurated, likely attributed to photosynthetic activity on the pellets. The δ13Corg values tend to be more elevated in indurated pellets, suggesting that heterotrophs are preferentially using enriched carbon sources. In contrast, friable pellets from nearshore areas show more negative δ13Corg values, suggesting microbial exposure to depleted C3 and CAM plant sources. Fingerprints of nitrogen fixation and denitrification are also documented and supported by δ15Norg values. Altogether, these findings suggest that EPS and a microbial consortium, including gut-microbial flora and free-living surface colonizers, are responsible for inducing early cements, which are later complemented by secondary cements. Microorganisms involved in pellet lithification may subsequently also aid in ooid cortex development.
{"title":"Lithification of pelletal grains by microbially mediated organomineralization","authors":"Mara R. Diaz , Kelly Bergman , Peter K. Swart , Gregor P. Eberli","doi":"10.1016/j.sedgeo.2024.106785","DOIUrl":"10.1016/j.sedgeo.2024.106785","url":null,"abstract":"<div><div>Fecal pellets are key components of the biological carbon pump and a source of nutrients. When cohesively bound and cemented, they become the most abundant non-skeletal grains in shallow-water carbonates and an important nucleus for ooid formation. Herein, we describe the mineralization processes contributing to pellet cementation using scanning electron microscopy in conjunction with stable isotope and mineralogical analyses of the bulk sediments on Great Bahama Bank, known for its abundance of peloids and fecal pellets. Results show biogenic signatures consistent with the initial stages of organomineralization. These include, curved-tubular filaments and bacilli bacteria associated with extracellular polymeric substances (EPS); fibrils of EPS binding aragonite needles; and the coexistence of decayed EPS with amorphous calcium carbonate that once it develops, coalesces and crystalizes into aragonite. While δ<sup>13</sup>C<sub>inorg</sub> do not show large variations, slightly higher values are observed in areas where pellets are indurated, likely attributed to photosynthetic activity on the pellets. The δ<sup>13</sup>C<sub>org</sub> values tend to be more elevated in indurated pellets, suggesting that heterotrophs are preferentially using enriched carbon sources. In contrast, friable pellets from nearshore areas show more negative δ<sup>13</sup>C<sub>org</sub> values, suggesting microbial exposure to depleted C3 and CAM plant sources. Fingerprints of nitrogen fixation and denitrification are also documented and supported by δ<sup>15</sup>N<sub>org</sub> values. Altogether, these findings suggest that EPS and a microbial consortium, including gut-microbial flora and free-living surface colonizers, are responsible for inducing early cements, which are later complemented by secondary cements. Microorganisms involved in pellet lithification may subsequently also aid in ooid cortex development.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"476 ","pages":"Article 106785"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.sedgeo.2024.106802
Teresa Serra, Marianna Soler, Jordi Colomer
Turbidity currents are mechanisms that transport sediment from continental landscapes into coastal areas and therefore into oceans, reservoirs and lakes. Turbulence at the head of the turbidity current maintains sediment particles in suspension provided the mixing is greater than the settling velocity of the particles being transported. However, both the depositional regimes of the particles in turbidity currents and the extent of the hydrodynamical regimes still need to be better related. Likewise, the associated sedimentary patterns need to be related to the type of particles that form a turbidity current. In this study, a set of lock-exchange experiments in a flume were conducted to determine the extent and development of a turbidity current composed of different granulometric sediments and sediment concentrations. Both the extent of the inertial regime and the onset of the self-similar regime were determined and found to be dependent on the d50 of the sediment and the Rouse number (i.e. the balance between particle sedimentation and mixing due to the gravity current development). The results obtained from the sedimentation patterns bring new knowledge in explaining the gradation of sediments in turbidites and its relationship to the longitudinal hydrodynamics of a turbidity current as it develops.
{"title":"Sedimentation patterns from turbidity currents associated to hydrodynamical transport modes","authors":"Teresa Serra, Marianna Soler, Jordi Colomer","doi":"10.1016/j.sedgeo.2024.106802","DOIUrl":"10.1016/j.sedgeo.2024.106802","url":null,"abstract":"<div><div>Turbidity currents are mechanisms that transport sediment from continental landscapes into coastal areas and therefore into oceans, reservoirs and lakes. Turbulence at the head of the turbidity current maintains sediment particles in suspension provided the mixing is greater than the settling velocity of the particles being transported. However, both the depositional regimes of the particles in turbidity currents and the extent of the hydrodynamical regimes still need to be better related. Likewise, the associated sedimentary patterns need to be related to the type of particles that form a turbidity current. In this study, a set of lock-exchange experiments in a flume were conducted to determine the extent and development of a turbidity current composed of different granulometric sediments and sediment concentrations. Both the extent of the inertial regime and the onset of the self-similar regime were determined and found to be dependent on the d<sub>50</sub> of the sediment and the Rouse number (i.e. the balance between particle sedimentation and mixing due to the gravity current development). The results obtained from the sedimentation patterns bring new knowledge in explaining the gradation of sediments in turbidites and its relationship to the longitudinal hydrodynamics of a turbidity current as it develops.</div></div>","PeriodicalId":21575,"journal":{"name":"Sedimentary Geology","volume":"476 ","pages":"Article 106802"},"PeriodicalIF":2.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}