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Hassenruck-Gudipati, Hima J., Thaddeus Ellis, Timothy A. Goudge, and David Mohrig. "A multi-proxy assessment of terrace formation in the lower Trinity River valley, Texas." Earth Surface Dynamics 10, no. 3 (2022): 635–51. http://dx.doi.org/10.5194/esurf-10-635-2022.
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Abstract. A proposed null hypothesis for fluvial terrace formation is that internally generated or autogenic processes, such as lateral migration and river-bend cutoff, produce variabilities in channel incision that lead to the abandonment of floodplain segments as terraces. Alternatively, fluvial terraces have the potential to record past environmental changes from external forcings that include temporal changes in sea level and hydroclimate. Terraces in the Trinity River valley have been previously characterized as Deweyville groups and interpreted to record episodic cut and fill during late Pleistocene sea level variations. Our study uses high-resolution topography of a bare-earth digital elevation model derived from airborne lidar surveys along ∼ 88 linear kilometers of the modern river valley. We measure both differences in terrace elevations and widths of paleo-channels preserved on these terraces in order to have two independent constraints on terrace formation mechanisms. For 52 distinct terraces, we quantify whether terrace elevations fit distinct planes – expected for allogenic terrace formation tied to punctuated sea level and/or hydroclimate change – by comparing variability in a grouped set of Deweyville terrace elevations against variability associated with randomly selected terrace sets. Results show Deweyville groups record an initial valley floor abandoning driven by allogenic forcing, which transitions into autogenic forcing for the formation of younger terraces. For these different terrace sets, the slope amongst different terraces stays constant. For 79 paleo-channel segments preserved on these terraces, we connected observed changes in paleo-channel widths to estimates for river paleo-hydrology over time. Our measurements suggest the discharge of the Trinity River increased systematically by a factor of ∼ 2 during the late Pleistocene. Despite this evidence of increased discharge, the similar down-valley slopes between terrace sets indicate that there were likely no increases in sediment-to-water discharge ratios that could be linked to allogenic terrace formation. This is consistent with our elevation clustering analysis that suggests younger terraces are indistinguishable in their elevation variance from autogenic terrace formation mechanisms, even if the changing paleo-channel dimensions might, viewed in isolation, provide a mechanism for allogenic terrace formation. Methods introduced here combine river-reach-scale observations of terrace sets and paleo-hydrology with local observations of terraces and paleo-channels to show how interpretations of allogenic versus autogenic terrace formation can be evaluated within a single river system.
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Bellwald, B., S. Planke, S. Polteau, et al. "Characterization of a glacial paleo-outburst flood using high-resolution 3-D seismic data: Bjørnelva River Valley, SW Barents Sea." Journal of Glaciology 67, no. 263 (2021): 404–20. http://dx.doi.org/10.1017/jog.2020.115.
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AbstractProglacial braided river systems discharge large volumes of meltwater from ice sheets and transport coarse-grained sediments from the glaciated areas to the oceans. Here, we test the hypothesis if high-energy hydrological events can leave distinctive signatures in the sedimentary record of braided river systems. We characterize the morphology and infer a mode of formation of a 25 km long and 1–3 km wide Early Pleistocene incised valley recently imaged in 3-D seismic data in the Hoop area, SW Barents Sea. The fluvial system, named Bjørnelva River Valley, carved 20 m deep channels into Lower Cretaceous bedrock at a glacial paleo-surface and deposited 28 channel bars along a paleo-slope gradient of ~0.64 m km−1. The landform morphologies and position relative to the paleo-surface support that Bjørnelva River Valley was formed in the proglacial domain of the Barents Sea Ice Sheet. Based on valley width and valley depth, we suggest that Bjørnelva River Valley represents a braided river system fed by violent outburst floods from a glacial lake, with estimated outburst discharges of ~160 000 m3 s−1. The morphological configuration of Bjørnelva River Valley can inform geohazard assessments in areas at risk of outburst flooding today and is an analogue for landscapes evolving in areas currently covered by the Greenland and Antarctic ice sheets.
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de Weger, Wouter, F. Javier Hernández-Molina, Rachel Flecker, et al. "Late Miocene contourite channel system reveals intermittent overflow behavior." Geology 48, no. 12 (2020): 1194–99. http://dx.doi.org/10.1130/g47944.1.
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Abstract Paleoceanographic information from submarine overflows in the vicinity of oceanic gateways is of major importance for resolving the role of ocean circulation in modulating Earth’s climate. Earth system models are currently the favored way to study the impact of gateways on global-scale processes, but studies on overflow-related deposits are more suitable to understand the detailed changes. Such deposits, however, had not yet been documented in outcrop. Here, we present a unique late Miocene contourite channel system from the Rifian Corridor (Morocco) related to the initiation of Mediterranean Outflow Water (MOW). Two channel branches were identified consisting of three vertically stacked channelized sandstone units encased in muddy deposits. Both branches have different channel-fill characteristics. Our findings provide strong evidence for intermittent behavior of overflow controlled by tectonic processes and regional climatic change. These fluctuations in paleo-MOW intermittently influenced global ocean circulation.
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Bukar, Shettima, Mohammed Bukar, Asabe Kuku, Bintu Shettima, and Ishaku H. Kamale. "Incised Valley Depositional System of the Cretaceous Yolde Formation of the Gongola Sub-basin Northern Benue Trough N.E. Nigeria." European Journal of Engineering Research and Science 5, no. 8 (2020): 870–76. http://dx.doi.org/10.24018/ejers.2020.5.8.1999.
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This research was carried out in the Gongola Sub-basin of the Northern Benue Trough aimed at deciphering of the paleo-depositional environment of the Yolde Formation based on facies on facies analysis. Six lithofacies were identified to include trough crossbedded sandstone facies (St), massive bedded sandstone facies (Sm), planar crossbedded sandstone facies (Sp), ripple laminated sandstone facies (Sr), parallel sandstone facies (Sl) and mudstone facies (Fm). These build into two facies association of fluvial channel and tidally influenced fluvial channel facies associations. The fluvial successions typical characterizes the lower stratigraphic horizons and their contained dominances of trough crossbedded sandstone facies with high channel to overbank facies and contained mud-clast reflecting deep, high energy braided river system. The submergences of these channels by surging sea level rise generated the tidally influenced fluvial facies association and this package characteristically defines the upper interval stratigraphic architecture of this formation, displaying occasional bi-directional current system and abundant marine ichnogenera. This architectural symmetry is reflective of an incised valley fills, developing as a consequence of Cenomanian transgressive phase induced by the mid-Cretaceous global marine transgression.
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Bukar, Shettima, Mohammed Bukar, Asabe Kuku, Bintu Shettima, and Ishaku H. Kamale. "Incised Valley Depositional System of the Cretaceous Yolde Formation of the Gongola Sub-basin Northern Benue Trough N.E. Nigeria." European Journal of Engineering and Technology Research 5, no. 8 (2020): 870–76. http://dx.doi.org/10.24018/ejeng.2020.5.8.1999.
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This research was carried out in the Gongola Sub-basin of the Northern Benue Trough aimed at deciphering of the paleo-depositional environment of the Yolde Formation based on facies on facies analysis. Six lithofacies were identified to include trough crossbedded sandstone facies (St), massive bedded sandstone facies (Sm), planar crossbedded sandstone facies (Sp), ripple laminated sandstone facies (Sr), parallel sandstone facies (Sl) and mudstone facies (Fm). These build into two facies association of fluvial channel and tidally influenced fluvial channel facies associations. The fluvial successions typical characterizes the lower stratigraphic horizons and their contained dominances of trough crossbedded sandstone facies with high channel to overbank facies and contained mud-clast reflecting deep, high energy braided river system. The submergences of these channels by surging sea level rise generated the tidally influenced fluvial facies association and this package characteristically defines the upper interval stratigraphic architecture of this formation, displaying occasional bi-directional current system and abundant marine ichnogenera. This architectural symmetry is reflective of an incised valley fills, developing as a consequence of Cenomanian transgressive phase induced by the mid-Cretaceous global marine transgression.
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Pelletier, J. D. "The linkage between hillslope vegetation changes and late-Quaternary fluvial-system aggradation in the Mojave Desert revisited." Earth Surface Dynamics Discussions 2, no. 1 (2014): 181–213. http://dx.doi.org/10.5194/esurfd-2-181-2014.
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Abstract. Valley-floor-channel and alluvial-fan deposits and terraces in the southwestern US record multiple episodes of late Quaternary fluvial aggradation and incision. Perhaps the most well constrained of these episodes took place from the latest Pleistocene to the present in the Mojave Desert. One hypothesis for this episode, i.e. the paleo-vegetation change hypothesis (PVCH), posits that a reduction in hillslope vegetation cover associated with the transition from Pleistocene woodlands to Holocene desert scrub generated a pulse of sediment that triggered a primary phase of aggradation downstream, followed by channel incision, terrace abandonment, and initiation of a secondary phase of aggradation further downstream. A second hypothesis, i.e. the extreme-storm hypothesis, attributes episodes of aggradation and incision to changes in the frequency and/or intensity of extreme storms. In the past decade a growing number of studies has advocated the extreme-storm hypothesis and challenged the PVCH on the basis of inconsistencies in both timing and process. Here I show that in eight out of nine sites where the timing of fluvial-system aggradation in the Mojave Desert is reasonably well constrained, measured ages of primary aggradation and/or incision are consistent with the predictions of the PVCH if the time-transgressive nature of paleo-vegetation changes with elevation is fully taken into account. I also present an alternative process model for PVCH that is more consistent with available data and produces sediment pulses primarily via an increase in drainage density (i.e. a transformation of hillslopes into low-order channels) rather than solely via an increase in sediment yield from hillslopes. This paper further documents the likely important role of changes in upland vegetation cover and drainage density in driving fluvial-system response during semiarid-to-arid climatic changes.
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Bindi, L., F. Tasselli, F. Olmi, A. Peccerillo, and S. Menchetti. "Crystal chemistry of clinopyroxenes from Linosa Volcano, Sicily Channel, Italy: implications for modelling the magmatic plumbing system." Mineralogical Magazine 66, no. 6 (2002): 953–68. http://dx.doi.org/10.1180/0026461026660070.
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Abstract The Island of Linosa is a small part of the large submarine volcanic complex which is locatedat the SW edge of the Linosa Graben, Sicily Channel. The island was formed between 1.06±0.10 and 0.53±0.07 Ma, through three main stages of activity: Paleo-Linosa, Arena Bianca and Monte Bandiera. Major and trace element data show that the compositional variability of the three activity stages is limited, with most of the rocks showing basaltic to hawaiitic composition. Evolved benmoreites and trachytes are foundas lithics in some pyroclastic units of Paleolinosa. The mafic rocks of the three stages show porphyritic texture, with phenocryst assemblages characterized by olivine, clinopyroxene and plagioclase. The volume ratio of olivine vs. clinopyroxene decreases from early to late stages of activity in mafic rocks with comparable major element composition. Clinopyroxene phenocrysts from mafic rocks of the three stages have poorly variable composition, clustering in the augite field. Phenocrysts from the first activity stage (Paleo-Linosa), show a slight increase in TiO2, Al2O3 and CaO, and a decrease of Fe2O3 (total) with the increasing SiO2 content of the host rocks. Crystals from the second and the third stage (Arena Bianca and Monte Bandiera) display a slightly more restricted range of FeOtot, frequently with very high MgO, Al2O3 and TiO2 contents. Crystal chemical investigation of clinopyroxenes from rocks of the three stages with comparable degrees of evolution, revealed significant variation of structural parameters, in particular VM1 and Vcell. These show a consistent decrease, passing from clinopyroxenes of the early stage to crystals extracted from the mafic lavas of stages 2 and 3. Given the similar compositional ranges of the host rocks, structural variations of clinopyroxenes are interpreted to reveal modifications of crystallization pressure, which increased, passing from Paleo-Linosa to the Arena Bianca and Monte Bandiera stages. Given this information, the observed crystal-chemical variations provide information on the depth of magma reservoirs and on the evolution of the plumbing system of Linosa volcano.
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Rivett, Michael O., Shona Symon, Lucas Jacobs, et al. "Paleo-Geohydrology of Lake Chilwa, Malawi is the Source of Localised Groundwater Salinity and Rural Water Supply Challenges." Applied Sciences 10, no. 19 (2020): 6909. http://dx.doi.org/10.3390/app10196909.
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Meeting long-term rural community water supply needs requires diligent geohydrological conceptualisation. Study of Malawi’s Lake Chilwa Basin, including sampling of 330 water points in Phalombe District, enabled assessment of groundwater quality influence upon supply. The control of larger Lake Chilwa paleo-environments on current Basin groundwater quality is demonstrated. Lacustrine sediment deposition forming high-level deposits under open lake conditions and terrace deposits under open and closed lake conditions significantly control the groundwater major-ion quality and salinity now observed. Paleo-lake extent marks the transition between low-TDS (total dissolved solids) groundwater suitable for water supply at higher elevations and high-TDS brackish groundwater in areas overlain by lacustrine deposits closer to the current lake level. Low-TDS groundwater is limited to mid-to-low reach influent leakage of rivers incising terraces. Permeable fluvial deposits within the deeper paleo-river channel may possibly provide low-TDS water. The conceptual model, whereby paleo-lake controls groundwater salinity, provides science-based evidence to address policy to manage the significant water point functionality concerns quantified at the district and river basin scales. Targeting of the low-TDS groundwater alongside improved use of upland low-TDS stream/river sources with fewer, but larger capacity, and better maintained gravity-fed supply schemes are recommended. This study hence shows the value of paleo-geohydrology interpretation of the lake–groundwater system conceptualisation to inform Sustainable Development Goal 6 (SDG 6.5.1)—integrated water resources management policy for rural water supply.
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Wills, W. H., David W. Love, Susan J. Smith, et al. "Water Management at Pueblo Bonito: Evidence from the National Geographic Society Trenches." American Antiquity 81, no. 3 (2016): 449–70. http://dx.doi.org/10.1017/s0002731600003942.
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Recent archaeological investigations at Pueblo Bonito in Chaco Canyon reveal that residents constructed a large diversion channel during the eleventh century A.D. as dramatic growth resulted in the expansion of the building onto the main valley floor. Sediments in the diversion channel reflect repeated episodes of flooding, rather than slow moving water typically found in irrigation canals, and archaeobotanical data indicate deposition during late summer or early fall. Although an agricultural function is possible, the channel may have been built primarily to divert floodwaters away from Pueblo Bonito while providing a nearby water source for construction and domestic use. The diversion channel was destroyed by the entrenchment of the “Bonito paleo-channel” in the late A.D. 1000s, and then buried by a combination of cultural debris and valley flooding. Although the canyon stream system changed throughout the occupation of Pueblo Bonito, there is no evidence that the formation of a deep natural channel in the floodplain had any negative effect on the growth of the great house
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Château, Chloé C. F., Shahin E. Dashtgard, and James A. MacEachern. "Refinement of the stratigraphic framework for the Regional C depositional unit of the McMurray Formation and implications for the early transgression of the Alberta Foreland Basin, Canada." Journal of Sedimentary Research 90, no. 10 (2020): 1322–45. http://dx.doi.org/10.2110/jsr.2020.62.
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ABSTRACT The Lower Cretaceous McMurray Formation in Alberta and Saskatchewan, Canada, comprises a series of depositional units (DUs) consisting of stacked parasequences bounded by flooding surfaces and incised by fluvio-estuarine channel belts. The fluvio-estuarine channel belts of the McMurray Fm have been the focus of numerous studies whereas the regional DUs have received substantially less attention. Of the regional DUs, Regional C (equivalent to the middle McMurray) is the most understudied, yet this interval records the history of the McMurray Formation between deposition of fluvial strata in the lower McMurray and marine facies in the upper McMurray and overlying Clearwater Formation. Determining the history of the Regional C DU is fundamental for accurately reconstructing the stratigraphic evolution of the McMurray Fm and, by extension, the early evolution of the Alberta Foreland Basin. The Regional C is divided into two DUs separated by a regionally mappable flooding surface. This surface occurs 11 to 15 m below the top of the Regional C and is traceable over a 2,550 km2 area. This flooding surface divides the thick interval of undifferentiated Regional C into a lower C2 DU and an upper C1 DU, each with a maximum thickness of < 15 m. The thickness of the C2 and C1 DUs indicates that deposition at this time also occurred in a setting of low to moderate accommodation creation, which is consistent with the rest of the McMurray Formation. The limited available accommodation space was easily surpassed by sediment supplied by the paleo-distributive channel system, leading to a basinward progradation of the shoreline. The C2 and C1 DUs are retrogradationally stacked, with the maximum regressive paleo-shoreline of C1 lying landward of that of C2. This stacking arrangement indicates that the shoreline backstepped during the early stages of transgression of the Boreal Sea. The backstepping of the paleo-shoreline from C2 to C1 time is consistent with previous studies that show continued and stepwise retrogradation and/or transgression of the paleo-shoreline from the onset of deposition in the lower McMurray Formation through to maximum transgression in the Clearwater Formation. Together, these studies demonstrate that the early drowning of the Alberta Foreland Basin was persistent and slow.
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Shan, Xiaocai, Fei Tian, Fuqi Cheng, Changchun Yang, and Wei Xin. "Spectral Decomposition and a Waveform Cluster to Characterize Strongly Heterogeneous Paleokarst Reservoirs in the Tarim Basin, China." Water 11, no. 2 (2019): 256. http://dx.doi.org/10.3390/w11020256.
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The main components of the Ordovician carbonate reservoirs in the Tahe Oilfield are paleokarst fracture-cavity paleo-channel systems formed by karstification. Detailed characterization of these paleokarst reservoirs is challenging because of heterogeneities in characteristics and strong vertical and lateral non-uniformities. Traditional seismic analysis methods are not able to solve the identification problem of such strongly heterogeneous reservoirs. Recent developments in seismic interpretation have heightened the need to describe the fracture-cavity structure of a paleo-channel with more accuracy. We propose a new prediction model for fracture-cavity carbonate reservoirs based on spectral decomposition and a waveform cluster. By the Matching Pursuit decomposition algorithm, the single-frequency data volumes are obtained. The specific frequency data volume that is the most sensitive to the reservoir is chosen based on seismic synthesis traces of well-logging data and geological interpretability. The waveform cluster is then applied to delineate the complex paleokarst systems, particularly the fracture-caves in the runoff zone. This method was applied to the area around Well T615 in the Tahe oilfield, and a paleokarst fracture-cavity system with strong heterogeneity in the runoff zone was delineated and characterized. The findings of this research provide insights for predicting other similar karst systems, such as karstic groundwater and karst hydrogeological systems.
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Carraro, Davide, Dario Ventra, and Andrea Moscariello. "Anatomy of a fluvial paleo-fan: sedimentological and architectural trends of the Paleocene–Eocene Wasatch–Colton System (western Uinta Basin, Utah, U.S.A.)." Journal of Sedimentary Research 93, no. 6 (2023): 370–412. http://dx.doi.org/10.2110/jsr.2022.095.
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ABSTRACT Recent developments in fluvial geomorphology and sedimentology suggest that fluvial fans (also known as distributive fluvial systems) could be responsible for the accumulation of great volumes of clastic successions in continental basins. A general depositional model based on sedimentological and architectural trends has been formulated for these fluvial systems, however, their recognition in the stratigraphic record often relies on partially preserved, discontinuous successions. This study provides a sedimentological and architectural characterization of Paleogene alluvial strata of the Wasatch and Colton formations in the southwestern Uinta Basin, central Utah (U.S.A.), following an ∼ 120-km-long outcrop belt which records deposition from an alluvial wedge that prograded to the north and northwest, from the basin margin to distal lake-dominated environments, preceding the onset of ancient Lake Uinta. Lateral and vertical distribution of facies associations are presented from a dataset of field observations (thirteen logged stratigraphic sections, for a total of ∼ 2400 m) and virtual outcrop models along the proximal-to-distal extent of the Wasatch–Colton alluvial system. Four sectors are defined (proximal, medial, distal, and terminal) to mark the longitudinal heterogeneity of alluvial stratigraphy. Noteworthy trends comprise a downstream decrease in the overall thickness of the alluvial stratigraphic column, a reduction in the relative volume, architectural complexity, and amalgamation of fluvial-channel bodies away from the apex, a weak downstream-fining trend in channel sandstones, and a down-system increase in preserved overbank and floodplain deposits accompanied by increasing volume and facies complexity of preserved lacustrine and palustrine facies associations. A proximal-to-distal change in fluvial-channel architecture is noted, with proximal sections characterized by vertically and laterally amalgamated sheet-like channel fills, transitioning to a lesser degree of amalgamation towards the medial sector, whereas distal and terminal sections are dominated by floodplain fines enveloping a subordinate volume of isolated, ribbon-shaped channel-sandstone bodies. The temporal development of the stratigraphic succession is observed in its entirety throughout the field area and, albeit localized, channel-scale erosion and potential depositional hiatuses punctuate the stratigraphy. Two major system-scale trends have been described in the Wasatch–Colton System (WCS). A first-order, long-term progradational trend, especially evident in proximal and medial sections, encompasses the large-scale vertical patterns in facies and architecture vertically through most of the stratigraphy of the WCS. In contrast, the uppermost part of the stratigraphic succession is characterized by a reverse, retrogradational trend, possibly associated with the early transgression of Lake Uinta's southern margin, marking the base of the overlying Green River Formation. Albeit expressed by different vertical succession of facies, proximal-to-distal processes, and stratal patterns documented along a longitudinal transect of the WCS mirror substantially identical vertical trends through the stratigraphy, which are interpreted as Waltherian superposition of distinct depositional domains during fluvial-fan progradation. Analyses of sandstone petrography and zircon geochronology suggest a unified source for the fluvial system, also supporting an interpretation as a distributive, rather than a tributive, fluvial system. This study enhances our understanding of the current depositional model for extensive fluvial-fan successions via a regional-scale stratigraphic analysis of a fluvial paleo-fan based on integrated characterization of both vertical and down-system patterns in facies distribution and fluvial architecture, providing key insights on useful criteria for recognizing fluvial-fan successions from the rock record.
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Li, Yifan, Xiaojie Wei, Kui Liu, and Kening Qi. "Sequence Stratigraphic and Geochemical Records of Paleo-Sea Level Changes in Upper Carboniferous Mixed Clastic–Carbonate Successions in the Eastern Qaidam Basin." Journal of Marine Science and Engineering 13, no. 7 (2025): 1299. https://doi.org/10.3390/jmse13071299.
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The Upper Carboniferous strata in the eastern Qaidam Basin, comprising several hundred meters of thick, mixed clastic–carbonate successions that have been little reported or explained, provide an excellent geological record of paleoenvironmental and paleo-sea level changes during the Late Carboniferous icehouse period. This tropical carbonate–clastic system offers critical constraints for correlating equatorial sea level responses with high-latitude glacial cycles during the Late Paleozoic Ice Age. Based on detailed outcrop observations and interpretations, five facies assemblages, including fluvial channel, tide-dominated estuary, wave-dominated shoreface, tide-influenced delta, and carbonate-dominated marine, have been identified and organized into cyclical stacking patterns. Correspondingly, four third-order sequences were recognized, each composed of lowstand, transgressive, and highstand system tracts (LST, TST, and HST). LST is generally dominated by fluvial channels as a result of river juvenation when the sea level falls. The TST is characterized by tide-dominated estuaries, followed by retrogradational, carbonated-dominated marine deposits formed during a period of sea level rise. The HST is dominated by aggradational marine deposits, wave-dominated shoreface environments, or tide-influenced deltas, caused by subsequent sea level falls and increased debris supply. The sequence stratigraphic evolution and geochemical records, based on carbon and oxygen isotopes and trace elements, suggest that during the Late Carboniferous period, the eastern Qaidam Basin experienced at least four significant sea level fluctuation events, and an overall long-term sea level rise. These were primarily driven by the Gondwana glacio-eustasy and regionally ascribed to the Paleo-Tethys Ocean expansion induced by the late Hercynian movement. Assessing the history of glacio-eustasy-driven sea level changes in the eastern Qaidam Basin is useful for predicting the distribution and evolution of mixed cyclic succession in and around the Tibetan Plateau.
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Hayes, Robert, and Peter DeCelles. "Reconstructing paleosinuosity and sedimentary mass balance in the Upper Triassic Shinarump paleoriver in Utah and Arizona, U.S.A." Journal of Sedimentary Research 92, no. 12 (2022): 1207–32. http://dx.doi.org/10.2110/jsr.2021.122.
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ABSTRACT The Upper Triassic Shinarump Member forms the basal part of the Chinle Formation in the western interior United States and was deposited by a continental-scale fluvial system which ran approximately 2,500 km from the Ouachita Orogen in the east into the Auld Lang Syne marine basin in the west. Previous studies of the Shinarump Member have concluded that the deposits represent a braided-river system but have not produced estimates for paleo-sinuosity and paleo-discharge. Recent advances in sedimentology allow detailed morphometric assessment of the nature of the river system that deposited the Shinarump Member enabling us to produce quantitative estimates for these parameters. We therefore present architectural data from the Shinarump Member in northern Arizona and Utah, supported by lithofacies data and 39 sandstone petrographic analyses, and a dataset of 4,298 paleocurrent measurements from trough cross-strata. Lithofacies and architectural analysis supports previous interpretations of the Shinarump and equivalent strata as braided-river deposits. Petrographic analysis shows that the Shinarump is dominated by monocrystalline quartz and exhibits low spatial variation in composition, ranging from 85.4% to 99.8% total quartz. Paleocurrent measurements are used to calculate the channel sinuosity of the fluvial system as varying between 1.02 and 1.77, with a median value of 1.33 (compared to the Yangtze River, ranging from 1.05 to 1.50 and the Ganges–Brahmaputra, ranging from 1.05 to 1.13 in their lower 250 km). Paleohydrological estimates using data from the architectural surveys produce slope estimates from 2.01 × 10–4 to 6.51 × 10–4 and bankfull discharge estimates from 4.36 × 103 m3 s–1 to 2.38 × 104 m3 s–1 for individual channels, comparable to extant continental-scale fluvial systems. Estimates of lifetime sediment transport volume range from 7.75 × 104 km3 to 6.09 × 105 km3, which are in order-of-magnitude agreement with estimates for the volume of the depositional sink (1.35 × 105 km3 to 4.17 × 105 km3). These results demonstrate the potential for paleohydrologic estimates to provide new avenues for analysis of heavily studied units.
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Fan, Li, Zhuang Jiezao, Yu Jianjun, Du Quansheng, Dong Tailu, and Jiang Xiuhang. "Buried paleo-channel system and records of sea level changes on the continental shelf in Yingge Sea Basin." Chinese Journal of Oceanology and Limnology 8, no. 3 (1990): 240–48. http://dx.doi.org/10.1007/bf02849663.
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Caballero, Víctor Manuel, Julian Francisco Naranjo Vesga, Pedro David Gómez Gutiérrez, et al. "Eocene facies successions and environments in the Southern Llanos basin, Colombia." CT&F - Ciencia, Tecnología y Futuro 10, no. 1 (2020): 107–22. http://dx.doi.org/10.29047/01225383.141.
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This work presents the facies analysis and depositional environment for the Eocene rocks in the southern Llanos Basin (SLLB) and southern Llanos Foothills. Cores and outcrop samples were analyzed by palynology and detrital zircon U-Pbgeochronology. In this paper, we present ages for the facies and two important paleosol markers.
 The lower member of the Mirador Formation consists of amalgamated sandstones and conglomerates accumulated in a braidad channel belt. The lower Mirador is 33 m thick and early Eocene in the Foothills, whereas in the SLLB, it ist is 22 m thick and middle Eocene in age; it pinches out approximately 33 km to the east. The fluvial facies rests over an unconformity marked by a mature and intensively-weathered paleosol developed over Paleocene, Cretaceous and older rocks to the east. This mature paleosol was dated by U-Pb detrital zircon geochronology as middle to late Paleocene. At the top of the lower Mirador, we describe an interval of sandstones with root casts capped by a thin layer of coal or coaly mudstone. This facies succession evolved as A compound paleosol is a polygenetic soil that marks a change from well-drained conditions under a subaerial vegetation cover to poor-drained conditions of marsh and swamps, which halt vegetation growth, which is incorporated as coal or coaly mudstone, see the section of Facies Successions. At the top of the lower Mirador facies and recorded the cessation of the fluvial system and its stabilization by vegetation. The coal layer marked the posterior rise on the water table and flooding. Detrital zircon U-Pb geochronology dated this compound paleosol as middle Eocene.
 Above the fluvial facies of the lower Mirador, shallow marine facies deposited during the middle and late Eocene in the Foothills and western SLLB. The marine facies consist in shelf mudstone and shoreface sandstone in a coarsening upward trend. These facies correspond to the C8 member of the Carbonera Formation. The correlative middle Eocene facies to the east of the SLLB are carbonaceous mudstones and coals that were deposited in swamp-marsh and lagoon environments in backshore to coastal-plain environments during the middle Eocene.
 The fluvial and coastal plain, as well as the marine facies, fossilized an erosional relief less than 50 m high, corresponding to a paleo-landscape. The paleo-landscape was carved at the end of the Paleocene and is capped by the intensely-weathered paleosol indicating subaerial exposition. The paleo-landscape was modeled over Paleocene, Cretaceous, Paleozoic, and basement rocks toward the east and south of the basin. This paleo-landscape lasted until the end of the middle Eocene in the studied area.
 The Fluvial reservoirs are not continuous but distributed along channel belts composed of channels and braided bars in an NW direction. The marine shoreface reservoirs are distributed as swaths of sandstones in a perpendicular direction to the fluvial belts. These reservoirs have excellent seal rocks above. The plays include fluvial valley sandstones and buried hills of Cretaceous sandstones.
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Baioumy, Hassan, Chong Jing Ting, Sherif Farouk, and Khaled Al-Kahtany. "Facies architecture of fluviatile deposits of the Jurassic-Cretaceous Bertangga Formation, Peninsular Malaysia." Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 298, no. 2 (2020): 177–95. http://dx.doi.org/10.1127/njgpa/2020/0943.
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Bertangga Formation is a part of the Jurassic-Cretaceous non-marine sequences in Thailand and Malaysia. However, its facies analysis and depositional model have not been investigated in detail. Eleven lithofacies have been described in the Bertangga Formation and combined five facies associations including channel, point bar, floodplain, crevasse splay and swamp facies associations. Channel deposits are stacked bodies of fining upward sequences with prevalent erosional bases, formed by vertical aggradation and avulsion of channels. Point bar sands comprise cross bedded sandstone bodies formed in upper flow regime and possible lateral accretion surfaces. Crevasse splay deposits form sheets of fine-to-medium-grained sandstone. Floodplain sediments are composed of motteled grey mudstone. Swamp depositional environment is characterized by an association of coal, carbonaceous shale and siltstone. Facies analysis allows reconstruction of the depositional environment of the Bertangga Formation as a meandering fluvial system. Facies association also shows the increasingly distal and fine-grained trend from west to east of the studied area, which suggests possible eastward paleo-flow direction of the river. The existence of kaolinite in all samples indicates weathering of felsic rocks under acidic conditions. In the same time, the presence of smectite in the eastern part of the study area may suggest a contribution of mafic and/or volcanic rocks to the source of sediments in this area.
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Invernizzi, Daniele, Moreno Pizzutto, Fabrizio Felletti, George Pantopoulos, Mattia Marini, and Adam Mcarthur. "Reconstruction of the sedimentary heterogeneity in outcropping deep-water channel–levee deposits (Taza–Guercif Basin, late Tortonian, NE Morocco)." Journal of Sedimentary Research 95, no. 2 (2025): 314–41. https://doi.org/10.2110/jsr.2024.040.
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ABSTRACT In the context of subsurface modeling of deep-water sedimentary systems, it is crucial to confidently identify turbidite channel–levee architectural elements in ancient strata. This becomes particularly critical when working with data of limited resolution, such as wireline well or seismic data. Similarly, in areas with limited outcrop exposure, establishing the temporal relationships of channel–levee systems relies predominantly on inference. Moreover, the paucity of well-documented outcrops exhibiting a continuous sedimentary record between channel-fill and overbank sediments remains a challenge. This work presents the sedimentary architecture of channel–levee Complex 7, one of the late Tortonian (Miocene) slope channel–levee complexes constituting the Tachrift System, which records the infill of the Taza–Guercif Basin in NE Morocco. The basin was on the southern margin of an ancient seaway (the Rifian Corridor) connecting the paleo–Mediterranean Sea and the Atlantic Ocean. The objective of this study is to comprehensively document the geometry, as well as the vertical and lateral heterogeneity of facies assemblages in the northwestern part of Complex 7. This approach encompasses geological mapping, detailed facies analysis from thirty-five sedimentary logs, and the implementation of physical stratigraphic correlations. Facies associations and stratigraphic architecture of Complex 7 reveal an eastward channel migration and a subsequent increase in flow energy. Due to exceptional 3-D exposures, this study offers a detailed sedimentological characterization of channel fills and their correlative levee deposits. It also provides valuable insights into the evolution of the parent channel, from its formation to its abandonment, while facilitating sub-seismic-scale lithological calibration for subsurface analogs.
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Fardiansyah, Iqbal, Agung Wiyono, and Abdullah Faisal Talib. "The Massive Fluvial Channel System in The Balam Graben: New Insight and Future Expectation from Menggala Formation in The Northern Rokan Block, Central Sumatera Basin." Indonesian Association of Geologists Journal 1, no. 2 (2021): 103–10. http://dx.doi.org/10.51835/iagij.2021.1.2.34.
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Menggala Formation has been long recognized as high quality oil bearing sand and favorable reservoir in Central Sumatera Basin (CSB). Regionally, this formation is unique in characteristic, distribution and has not been thoroughly evaluated during early exploration and development. This paper aims to explain elaborately the new stratigraphic feature and regional paleogeography model of Menggala Formation throughout Balam grabens by integrating cores, biostratigraphy, water salinity, well log and 2D seismic image to better understand regional stratigraphic play concept. Lower Menggala Formation in the northern Rokan Block has been clearly identified as the large scale of fluvial channel system that deposited parallel with Paleogene border fault remnants during early post-rift phase (22-25 million years ago). The fluvial channel belt is characterized by 4 to 5 km width, thick multi stacking fluvial sequence in the north and gradually change into river mouth sediment in the south. These sediments accumulated in depression area and also proven as huge productive reservoir in many fields. The north-south trending channel axis and geobodies confirmed by paleo bathymetric zonation, water salinity and 2D seismic image. The new paleogeography model helps better understanding of the regional stratigraphic concept of Menggala Formation across Balam grabens. In addition, this conceptual model also leads to strengthen the future exploration and development play concept within study area in Rokan Block.
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Brault, Nicolas, Francois Guillocheau, Jean-Noel Proust, et al. "Le systeme fluvio-estuarien Pleistocene moyen-superieur de Penestin (Morbihan); une paleo-Loire?" Bulletin de la Société Géologique de France 172, no. 5 (2001): 563–72. http://dx.doi.org/10.2113/172.5.563.
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Abstract In France, the basement domains are incised by large fluvial valley networks. Recent studies [Lefebvre et al., 1994; Bonnet, 1998; Lautridou et al., 1999; Antoine et al., 2000; Bonnet et al., 2000] show that these networks were cut during the Pleistocene in response to the uplift of western Europe combined with a fall of the base level [Haq et al., 1987; Shackleton, 1987]. The aim of this article is to study one of the rare Pleistocene sedimentary accumulations preserved in the Armorican Massif, the Penestin fluvial channel system in order to: (1) reconstitute the paleogeomorphological parameters and (2) discuss its relationships with recent tectonic movements. The Penestin fluvial system is localized at the top of the cliff of the Mine d'Or beach (west of Penestin, south of the Vilaine estuary, fig. 1). The paleochannel cuts through the Carboniferous micaschists which pass laterally into Tertiary paleoweathering deposits. The paleochannel is deformed by folds and/or by strike-slip faults. Three sectors are identified (fig. 2). Sector 1: a northern undeformed sub-area; sector 2: an intermediate slightly folded sub-area; sector 3 a southern folded and faulted sub-area. Three sedimentological units and seven associated facies are distinguished. Unit I (facies G), containing local matrix-dominated conglomerates characteristic of distal debris flows, suggests a proximal braided river environment, near the transition with alluvial fans [Blair and MacPherson, 1994]. Paleocurrent trends are directed toward N320 (fig. 3). Unit II (facies Sg, Sgm, Sf, Fb and T) is mainly dominated by sandy facies and corresponds to a more distal braided river flooded at the top by the sea (occurrence of inner estuarine deposits). The 2D and 3D megaripple cross-bedding structures indicate paleocurrents trending N320 (fig. 3). Unit III (facies G, Sg, Sgm and Fr) with multiple erosive channels is filled by braided river deposits (facies G, Sg and Sgm) or temporary lake sediments (facies Fr). The 2D and 3D megaripple cross-bedding structures indicate paleocurrents oriented N135 or N180 (fig. 3). Stratigraphically, these three units record two major base level cycles (fig. 6), in the sense of Wheeler [1958]. The first base level fall corresponds to the incision of the paleochannel. Unit I is amalgamated and was deposited during the beginning of the rise, while unit II corresponds to the maximal facies preservation during the maximum rate of rise. The erosion of unit II by unit III corresponds to a moderate base level fall followed by a small rise (little preservation of unit III). The basement, the weathering deposits and the Quaternary sedimentary units are folded and faulted by N050 to N070 strike-slip faults (fig. 2). Two stages of deformation can be characterized. The first stage, taking place before the incision of the paleochannel, corresponds to a southward tilting of the weathering profile. The second stage took place during the paleochannel infilling, producing thickness variations of the bedsets within unit II. The amount of deformation increased during deposition of unit III and is expressed by N050 to N070 strike-slip faults capped by unit III or by a topmost erosive surface. Fault orientation indicates a NNW-SSE compression (fig. 5) consistent with the stress field in northwestern Europe [Muller et al., 1992; Zoback, 1992]. Paleocurrent directions in units I and II seem to indicate a southerly drainage basin. Today, the Vilaine river flows southward. The units I and II do not represent a paleo-Vilaine river, but since unit III shows paleocurrents similar to those of the present Vilaine river and contains red schists in its basin. It could represent a paleo-Vilaine river. Units I and II might represent a paleo-Loire river, the present Loire river following a curve as it passes over the South Armorican shear zone which reorientates it toward the N320 (fig. 7). Tourenq and Pomerol [1995] show that the Loire river was captured many times ago by the Seine river during the Pleistocene. in this way, when the paleo-Loire river was captured, the paleo-Vilaine river deposited unit III. The Penestin paleochannel resulted from the fluviatile incision/filling of a braided river, which was temporarily overlain by estuarine deposits. The rivers filling this paleochannel first flowed out to the north (flow of a paleo-Loire river: units I and II), and then to the south (flow of a paleo-Vilaine river: unit III). The deformation is attributed to a N110 fault, to a set of N050 and N070 faults and to N050 folds.
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Devi, K., Shashank Sharma, and Rajesh Nair. "Evaluating spatial variability of subsurface carbon stock and free-phase gas using ground-penetrating radar and direct measurements in coastal landforms of South-West Indian peatlands." Journal of Physics: Conference Series 2141, no. 1 (2021): 012011. http://dx.doi.org/10.1088/1742-6596/2141/1/012011.
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Abstract Organic rich soils (peat) store significant amount of global soil carbon (C) in the form of methane (CH4) and carbon dioxide (CO2). Peat soils act as sinks and are a source of greenhouse gases (GHG) which occur in the form of Free Phase Gas in coastal landforms. South-West India has an extensive wetland system and is the primary source of GHG emissions, and CH4, in particular, has high potential to contribute to global climate change. In this scenario, this study sheds light on how SW Indian peatlands contribute to the global carbon cycle. The soil C stock and GHG spatial distribution in three distinct topographic coastal landforms within the peatland region were investigated: site 1, Muthukulam in the wetland boundary; site 2, Ramapuram in the paleo-sand ridge, and site 3, Eruva in the paleo-drainage channel. The combination of non-destructive Ground Penetrating Radar (GPR) and direct measurement (coring) in conjunction with the C core analysis helped in building the relationship between the GHG storage in the landforms of varying C stocks. Moreover, Common offset GPR has the ability to image subsurface features, lithological boundaries, coastal landforms, and peat-forming environments. The result from this study depicts the importance of different landforms in the storage of C and GHG in SW Indian peatlands.
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Reynolds, Tony. "“Grain-size bookkeeping,” a new aid for siliciclastic systems with examples from paralic environments." Journal of Sedimentary Research 89, no. 10 (2019): 976–1016. http://dx.doi.org/10.2110/jsr.2019.53.
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ABSTRACT Sedimentary logs form the foundation of many studies of ancient and modern sedimentary successions. In siliciclastic settings in particular, vertical grain-size trends are important records of past depositional processes and environments, so that they are recorded with care and are often central to final interpretations. It is rare for the actual grain size to play a similar role. Yet there is significant value in (i) digitizing sedimentary logs to produce statistical grain-size data and (ii) the deliberate study of grain size, a process described here as “grain-size bookkeeping.” To illustrate this, over 5.9 km of sedimentary logs have been digitized from the Miocene to Pliocene paleo–Orinoco delta, the Cretaceous Ferron Last Chance and Notom deltas, and the Jurassic Ravenscar Group. The digital data reveal how grain size partitions into distinct sedimentary facies, proximal-to-distal changes, changes related to stratigraphy and base level, and the overall grain size of paralic systems. It emerges that fluvio-distributary channels are the coarsest-grained sediment bodies in each of the studied systems. The coarsest material does not reach the shoreline, though the grain sizes of fluvio-distributary channels and shoreline sand bodies overlap, in accordance with the concept that the former feeds the later. By contrast, overbank sediments are relatively fine-grained, suggesting that, with the exception of channel belts, coarse sediment can largely bypass the delta plain. Grain-size changes occur across some key stratigraphic surfaces, but not consistently so. Channels in valleys are, on average, coarser than similar channels in unconfined systems, but, in the presented datasets, valleys do not contain the coarsest channels. The data have also allowed the analysis of down-system fining rates in ancient, sandy fluvio-distributary systems, with grain size being measured to decrease at rates ranging from 0.7 to 7.7 μm/km—values that compare favorably with modern rivers. Such large-scale trends are ornamented by, and link to, smaller-scale spatial changes associated with, for example, channel bars, crevasses, and mouth bars, and an initial dataset of associated fining rates has been collected. In general, very large systems (rivers) have low fining rates because of their great size, whereas the converse is true for small systems, especially if the grain size range is large. Consideration of downstream fining rates has led to the insight that avulsion initiates an unequal race to the shoreline. Suspended very fine sand and silt is likely to reach the shoreline with the avulsion flood waters, but bedload will advance far more slowly, perhaps too slowly to reach the shoreline before the river avulses again. Some avulsions may lead to notable temporal variations in the caliber of sediment supplied to shorelines. As expected, the largest system, the paleo-Orinoco, is the finest grained. The Ferron deltas have catchment areas 12 and 22 times smaller than the Orinoco, and are the coarsest grained. Remarkably, though their catchment areas differ by a factor of two, they have almost identical sand grain-size distributions. The data have also proved powerful in refining paleogeographic reconstructions, in particular suggesting “missing” depositional elements needed to complete local sediment routing systems. Careful tracking of grain size is also beneficial in that it is a key control on permeability, the description of which is crucial to the prediction of subsurface fluid flow.
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Osman, Ariana, Ronald J. Steel, Ryan Ramsook, Cornel Olariu, and Si Chen. "The arrival of the paleo–Orinoco Delta at Trinidad: The Cruse Formation delta lobes and delivery to deepwater Atlantic." Journal of Sedimentary Research 90, no. 8 (2020): 938–68. http://dx.doi.org/10.2110/jsr.2020.47.
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ABSTRACT Icehouse continental-shelf-margin accretion is typically driven by high-sediment-supply deltas and repeated glacio-eustatic, climate-driven sea-level changes on a ca. 100 ky time scale. The paleo–Orinoco margin is no exception to this, as the paleo–Orinoco River Delta with its high sediment load prograded across Venezuela, then into the Southern and Columbus basins of Trinidad since the late Miocene, depositing a continental-margin sedimentary prism that is > 12 km thick, 200 km wide, and 500 km along dip. The Cruse Formation (> 800 m thick; 3 My duration) records the first arrival of the paleo–Orinoco Delta into the Trinidad area. It then accreted eastwards, outwards onto the Atlantic margin, by shallow to deepwater clinoform increments since the late Miocene and is capped by a major, thick flooding interval (the Lower Forest Clay). Previous research has provided an understanding of the paleo–Orinoco Delta depositional system at seismic and outcrop scales, but a clinoform framework detailing proximal to distal reaches through the main fairway of the Southern Basin has never been built. We integrate data from 58 wells and outcrop observations to present a 3-D illustration of 15 mapped Cruse clinoforms, in order to understand the changing character of the first Orinoco clastic wedge on Trinidad. The clinoforms have an undecompacted average height of 550 m, estimated continental slope of 2.5° tapering to 1°, and a distance from shelf edge to near-base of slope of > 10 km. The clinoform framework shows trajectory changes from strong shelf-margin progradation (C10–C13) to aggradation (C14–C20) and to renewed progradation (C21–24). Cruse margin progradational phases illustrate oblique clinothem geometries that lack well-developed topsets but contain up to 70 m (200 ft) thick, deepwater slope channels. This suggests a high supply of sediment during periods of repeated icehouse rise and fall of eustatic sea level, with fall outpacing subsidence rates at times, and delivery of sand to the deepwater region of the embryonic Columbus channel region. Also, evidence of wholesale shelf-edge collapse and canyon features seen in outcrop strongly suggest that deepwater conduits for sediment dispersal and bypass surfaces for Cruse basin-floor fans do exist. The change to a topset aggradational pattern with a rising shelf trajectory may be linked to increased subsidence associated with eastward migration of the Caribbean plate. The Cruse-margin topsets were dominated by mixed fluvial–wave delta lobes that were effective in delivery of sands to the basin floor. The preservation of a fluvial regime of the delta may have been impacted by basin geometry which partly sheltered the area from the open Atlantic wave energy at the shelf edge. Ultimately, understanding shelf-edge migration style as well as process-regime changes during cross-shelf transits of the delta will help to predict the location of bypassed sands and their delivery to deepwater areas.
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Wei, Jiaying, Lei Li, Yong Xu, Guoqing Xue, Zhongpo Zhang, and Guohua Zhang. "Characterization and Numerical Modeling of Shallow Marine Turbidite Depositional Systems: A Case Study from the Second Member of the Yinggehai Formation, X Gas Field, Yinggehai Basin." Journal of Marine Science and Engineering 13, no. 6 (2025): 1107. https://doi.org/10.3390/jmse13061107.
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Objective: The research on turbid current deposition in shallow Marine shelf environments is relatively weak. Method: Based on three-dimensional seismic, drilling and logging data, etc., the spatio-temporal characterization of the shallow sea turbidity current sedimentary system was carried out by using seismic geomorphology and sedimentary numerical simulation techniques. Results and Conclusions: (1) A set of standards for identifying sedimentary units in the X Gas Field was established, identifying four sedimentary units: channel, mound body, channel-side accumulation body, and shelf mud; (2) The vertical evolution and planar distribution of the sedimentary units in the painting were precisely engraved. Along with the weakly–strongly–weak succession of turbidity current energy, the lithological combination of argillaceous siltstone–siltstone–mudstone developed vertically. On the plane, the clusters showed an evolution of isolation–connection–superposition. The scale of the river channel continued to expand, and the phenomena of oscillation and lateral accumulation occurred. (3) Three factors were analyzed: sea level, material sources, and sedimentary substrates (paleo landforms), and a shallow Marine turbidity current sedimentary system was established in the Honghe area in the northwest direction under the background of Marine receding, which is controlled by sedimentary slope folds and blocked by the high part of the diapause during the downward accumulation process of material sources along the shelf. (4) The numerical simulation results reconstructed the process of lateral migration of waterways, evolution of branch waterways into clusters, expansion of the scale of isolated clusters, and connection and superposition to form cluster complexes on a three-dimensional scale. The simulation results are in high agreement with the actual geological data.
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Vasilev, V. V., Yu G. Zenkova, D. V. Ponomareva, A. V. Permyakov, and R. R. Shakirov. "Accounting for paleo-channel sediments in the formation of a gas reservoir development system for the Novo-Chaselskoye oil-gas-condensate field." Neftyanoe khozyaystvo - Oil Industry, no. 8 (2020): 47–49. http://dx.doi.org/10.24887/0028-2448-2020-8-47-49.
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Wang, Wei, Yanxiu Shao, Jinyu Zhang, Wenxin Wang, and Renqi Lu. "Channel Profiles Reveal Fault Activity along the Longmen Shan, Eastern Tibetan Plateau." Remote Sensing 15, no. 19 (2023): 4721. http://dx.doi.org/10.3390/rs15194721.
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Assessing fault activity in regions lacking Quaternary sedimentary constraints remains a global challenge. In this study, we used channel slope distribution to examine variations in rock uplift along faults. By comparing channel steepness with published low-temperature thermochronology and paleo-seismic data, we identified deformation changes both perpendicular to and along the Longmen Shan at various time scales. Our data revealed distinct fault segments displaying distinct thrust activities along the Longmen Shan’s strike. In the southern segment, the Dachuan fault exhibited the highest activity, and its movement had persisted for millions of years. In the central segment, the Wenchuan fault was active during theearly Quaternary but has become dormant since the late Pleistocene. Within the past millions of years, the Yingxiu and Pengguan faults displayed significant vertical displacement. Fault activity in the northern Longmen Shan was relatively weak, with the Qingchuan fault transitioning from thrust movement during the Neogene to pure strike-slip activity since the Pleistocene. Overall, the Dachuan and Huya faults exhibited deformation patterns similar to the Yingxiu fault during the Quaternary. Similar to the Yingxiu fault, which triggered the Wenchuan earthquake, the Dachuan and Huya faults possess the capacity to produce significant earthquakes in the future. The variations in deformation perpendicular to and along the Longmen Shan fault system underscore the importance of upper crustal shortening in shaping the rock uplift patterns and topography of the eastern Tibetan Plateau margin.
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Koreny, John S., and Terry T. Fisk. "Hydraulic conductivity of the Portland Basin deep aquifer system." Environmental and Engineering Geoscience 6, no. 3 (2000): 279–92. http://dx.doi.org/10.2113/gseegeosci.6.3.279.
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Abstract The Portland Basin is 900 mi 2 in size and includes portions of Oregon and Washington. A deep aquifer system of the Troutdale Formation is used for municipal ground-water supply in both states over an area of approximately 300 mi 2 . Although lateral sedimentary facies variations are evident in the lithologic record, data from multi-well aquifer tests show that the aquifer forms a continuous hydrostratigraphic unit in both states. The aquifer is synclinal and in the center of the basin is well-confined by low-permeability layers. On the eastern and western margins of the basin, the aquifer is in hydraulic continuity with a buried Columbia River paleo-channel. The paleochannel forms a boundary to the aquifer and relative head differences between the aquifer and the river cause ground water to flow up the formation dip and against the Columbia River gradient in the eastern portion of the basin. The paleochannel acts as a discharge sink during low-pumping periods and a recharge source during extended pumping. Municipal use of ground water in the deep aquifers includes: a) continuous use which has increased from approximately 1 to 2 mgd in 1984 to 13 mgd in 1998 and, b) emergency use which has caused total use peaks of 55 mgd. The increased ground-water use has resulted in a modified flow regime causing the aquifer to receive induced recharge through the paleochannel deposits. The induced recharge available from the Columbia River may allow for further efficient development of groundwater supplies on the eastern and western margins of the basin.
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Chamberlain, Elizabeth L., and Jakob Wallinga. "Seeking enlightenment of fluvial sediment pathways by optically stimulated luminescence signal bleaching of river sediments and deltaic deposits." Earth Surface Dynamics 7, no. 3 (2019): 723–36. http://dx.doi.org/10.5194/esurf-7-723-2019.
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Abstract. Reconstructing sediment pathways in fluvial and deltaic systems beyond instrumental records is challenging due to a lack of suitable methods. Here we explore the potential of luminescence methods for such purposes, focusing on bleaching of the optically stimulated luminescence (OSL) signal of quartz sediments in a large fluviodeltaic system across time and space. We approach this by comparing residual doses of sand and silt from the modern Mississippi River channel with estimated residual doses of sand isolated from Late Holocene Mississippi Delta mouth bar and overbank deposits. Further insight is obtained from a comparison of burial ages of paired quartz sand and silt of Mississippi Delta overbank deposits. In contrast to some previous investigations, we find that the bleaching of the OSL signal is at least as likely for finer sediment as for coarser sediment of the meandering Mississippi River and its delta. We attribute this to the differences in light exposure related to transport mode (bedload vs. suspended load). In addition, we find an unexpected spatiotemporal pattern in OSL bleaching of mouth bar sand deposits. We suggest this may be caused by changes in upstream pathways of the meandering channel belt(s) within the alluvial valley or by distributary channel and coastal dynamics within the delta. Our study demonstrates that the degree of OSL signal bleaching of sand in a large delta can be highly time- and/or space-dependent. Silt is shown to be generally sufficiently bleached in both the modern Mississippi River and associated paleo-deposits regardless of age, and silt may therefore provide a viable option for obtaining OSL chronologies in megadeltas. Our work contributes to initiatives to use luminescence signals to fingerprint sediment pathways within river channel networks and their deltas and also helps inform luminescence dating approaches in fluviodeltaic environments.
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Matoshko, Andrei, Anton Matoshko, and Arjan de Leeuw. "The Plio–Pleistocene Demise of the East Carpathian Foreland Fluvial System and Arrival of the Paleo-Danube To The Black Sea." Geologica Carpathica 70, no. 2 (2019): 91–112. http://dx.doi.org/10.2478/geoca-2019-0006.
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Abstract This paper studies the Porat Formation (Fm.), which was deposited along the NE margin of the Dacian Basin part of the East Carpathian foreland (ECF) during the Pliocene and Early Pleistocene. We use a review of stratigraphic data in combination with lithofacies and sedimentary architecture analysis to interpret the Porat Fm. as a large sandy alluvial basin infill with an aggradational structure, consisting of cyclic successions of shallow sandy high-energy braided rivers. Aggradation of the Porat Fan was governed by subsidence of the Dacian Basin, along with a northerly supply of water and sediment from the Carpathians. Along the southern margin of the area the fan entered the Reni–Izmail-Trough, which formed the periodically active gateway between the Black Sea and Dacian basins. Along this trough, the Porat Fm. is developed in a different facies, discerned as the Dolynske Member (Mb. 1), which accumulated in the channel of a large river interpreted as the paleo-Danube. According to mammal stratigraphy of the Porat Fm. this continental-scale river had reached the area by the Gelasian to early Calabrian. The Porat alluvial infill indicates a stable water supply from the Carpathians, which explains the ecologically mixed fauna in its deposits: moistened forested alluvial plain-valleys were present between the zonally semi-arid steppe interfluves. The Porat Fm. and the previously studied late Miocene Balta Fm. are key elements for further in-depth study of the terrestrial evolution (tectonic–sedimentary–relief) of the ECF and north-western Black Sea coastal regions.
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Chajin-Ortiz, Patricia, Erick J. Illidge, and Sait Khurama. "Submarine canyon-fill reconstruction from integrated seismic-stratigraphic analysis – application to Banquereau formation, Scotian basin – offshore Canada." CT&F - Ciencia, Tecnología y Futuro 9, no. 2 (2019): 37–52. http://dx.doi.org/10.29047/01225383.119.
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Building geological models (integrating stratigraphic, structural and paleo-environmental 3D models) that allow the interpretation of sand bodies deposited by turbidity currents along submarine canyons or channels, is one of the most useful tools used by geoscientists for the definition of new drilling opportunities in both exploration and development phases. In this context, the integration of methodologies such as sequence stratigraphyand seismic attributes, together with well-log and core information, outline the basis for the interpretation of sand-body lithostratigraphy and chronostratigraphy. Similarly, these models allow the interpreter to reconstruct the depositional environment and deformation history of a sedimentary basin [1]. Based on a series of chronostratigraphic stages, this paper proposes a 3D model for the sedimentation history of the Banquereau Formation.This model is based on the integration of seismic stratigraphy, seismic attribute interpretation and well-log analysis. Also, a set of system tracts and corresponding transgression and regression phases were identified for the sedimentary interval of interest. The available dataset provided the information to identify the geometry and changes in the sedimentation patterns of the stratigraphic sequences from the Tertiary to the present, thus defining a 3D model of the sedimentological and structural architecture of this interval. Last but not least, theresulting 3D stratigraphic model made possible the identification and description of an amalgamated channel complex filling a submarine canyon associated with a fluvio-deltaic setting. This sort of analysis might be used as an analog for similar reservoirs, providing key insights and vital information for decision making.
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Cadena, Andrea F., and Roger M. Slatt. "Seismic and sequence stratigraphic interpretation of the area of influence of the Magdalena submarine fan, offshore northern Colombia." Interpretation 1, no. 1 (2013): SA53—SA74. http://dx.doi.org/10.1190/int-2013-0028.1.
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The area of influence of the Magdalena submarine fan, offshore northern Colombia, is a global frontier basin with sparse well control and only publically available 2D seismic from which to conduct exploration surveys. We have conducted a 2D seismic stratigraphic study to advance knowledge of the tectonostratigraphic evolution of this area and, furthermore, optimize exploration concepts to include stratigraphy and sedimentology to enhance such opportunities. Eight third-order seismic sequences from the early Miocene to Holocene comprise the stratigraphic record. Seismic character, thickness, and sedimentary processes vary in each sequence based on the area of deposition. Three geomorphologic areas are subject to deposition: the Tayrona depression, the undeformed central Magdalena fan and deformed wedges on either side of the fan. From oldest to youngest, sequences I to V represent bathyal paleo-environments that were deformed during the late Miocene Andean phase. Deformation of these sequences is thin skinned thrust sheets, where the main basal detachment corresponds to Oligocene shale. This deformation continued until the middle Pliocene, when sequence VI and VII were deposited on the Magdalena Fan mainly as mass transport and channel-levee deposits. Sequence VIII represents the record from early Pleistocene to the present time. From early Pliocene to present, erosion was mainly the product of submarine fan activity and bypass in areas of high slope, whereas for older deposits, erosion was caused by exposure to subaerial conditions. Superimposed on the third-order sequences are fourth-order sequences, which reveal a relative (tectonic-eustatic) sea level increase from Early Miocene to middle Late Miocene (Tortonian) time, followed by a lowstand event that extended until Holocene time. Potential reservoirs embedded within the sequences include sheet sands, channel fills, and levee-overbank. Other components of the petroleum system such as a mature source rock are still under debate.
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LIMA, ZULEIDE MARIA CARVALHO, ADRIANO DE LIMA ALVES, VENERANDO EUSTÁQUIO AMARO, and HELENICE VITAL. "Evolução da Linha de Costa do Esporão de Galinhos (NE Brasil) Utilizando Fotografias Aéreas e Imagens Landsat TM." Pesquisas em Geociências 28, no. 2 (2001): 497. http://dx.doi.org/10.22456/1807-9806.20324.
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Galinhos is one of many spits along the northern coast of Rio Grande do Norte state. Nowadays it has almost 10 km of extension in the E-W direction and medium width of 550 m. Sandy beaches, reefs, estuary, mangroves, lagoon, and dunes are the characteristic geomorphologic features. The modeling of these features is directly correlated with the united performance of waves, coastal current and winds, related with variations of the se level happened in the Quaternary. Aiming to monitoring the evolution of the coastline, it was used aerial photographs from 1954, 1967 and 1988 and satellite images from 1989 and 2000. After georeferred, the images were submitted to several techniques of digital processing, being applied synthesis techniques (dimensionality reduction) and emphasis of the information contained in the same ones, as: RGB colored compositions, index methods (NDWI), analysis for main components (PC’s) and space frequency filtering (directional filters). Each one of the six spectral bands (1-5 and 7) of the Landsat 5-TM and 7-ETM+ were submitted to contrast modifications of the histogram (lineal and no lineal contrast transformations). Among the applied processes, NDWI and the colored composition RGB 432 showed better results to the identification of the interface sea/earth. The application of directional filters allowed to observe submerged features, as sandwaves and photolineaments; the last one also observed in the aerial photographs, with direction NE-SW, which infers the existence of a paleo-channel, cutting the Galinhos spit, suggesting ancient system of island barrier developing for the current spit. The results show a ciclicity of erosional and accretionary processes, as well as the progress of the field of coastal dunes, located in the end East, burying the mangrove vegetation and silting up the tidal channel.
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Dill, Harald G., Andrei Buzatu, and Sorin-Ionut Balaban. "Straight to Low-Sinuosity Drainage Systems in a Variscan-Type Orogen—Constraints from Tectonics, Lithology and Climate." Minerals 11, no. 9 (2021): 933. http://dx.doi.org/10.3390/min11090933.
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A holistic-modular approach has been taken to study the evolution of three straight to low-sinuosity drainage systems (=SSS) in an uplifted basement block of the Central European Variscides. The development of the SSS is described by means of a quadripartite model. (1) The geological framework of the SSS: Forming the lithological and structural features in the bedrock as a result of different temperature, pressure and dynamic-metamorphic processes. (2) Prestage of SSS: Forming the paleo-landscape with a stable fluvial regime as a starting point for the SSS. (3) Proto-SSS: Transition into the metastable fluvial regime of the SSS. (4) Modern SSS: Operation of the metastable fluvial regime Tectonics plays a dual role. Late Paleozoic fold tectonic creates the basis for the studied SSS and has a guiding effect on the development of morphotectonic units during the Neogene and Quaternary. Late Cenozoic fault tectonics triggered the SSS to incise into the Paleozoic basement. The change in the bedrock lithology has an impact on the fluvial and colluvial sediments as well as their landforms. The latter reflects a conspicuous modification: straight drainage system ⇒ higher sinuosity and paired terraces ⇒ hillwash plains. Climate change has an indirect effect controlling via the bedrock the intensity of mechanical and chemical weathering. The impact on the development of the SSS can be assessed as follows: Tectonics >> climate ≅ bedrock lithology. The three parameters cause a facies zonation: (1) wide-and-shallow valley (Miocene), (2) wide-angle V-shaped valley (Plio-Pleistocene), (3) acute-angle V-shaped valley (Pleistocene), (4) V-shaped to U-shaped valleys (Pleistocene-Holocene). Numerical data relevant for the hydrographic studies of the SSS are determined in each reference area: (1) Quantification of fluvial and colluvial deposits along the drainage system, (2) slope angles, (3) degree of sinuosity as a function of river facies, (4) grain size distribution, (5) grain morphological categorization, (6) grain orientation (“situmetry”), (7) channel density, (8) channel/floodplain ratios. Thermodynamic computations (Eh, pH, concentration of solubles) are made to constrain the paleoclimatic regime during formation of the SSS. The current model of the SSS is restricted in its application to the basement of the Variscan-Type orogens, to an intermediate crustal maturity state.
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Peterson, Curt D., and Sandy Vanderburgh. "Tidal Flat Depositional Response to Neotectonic Cyclic Uplift and Subsidence (1–2 m) as Superimposed on Latest-Holocene Net Sea Level Rise (1.0 m/ka) in a Large Shallow Mesotidal Wave-Dominated Estuary, Willapa Bay, Washington, USA." Journal of Geography and Geology 10, no. 1 (2018): 109. http://dx.doi.org/10.5539/jgg.v10n1p109.
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The late-Holocene record of tidal flat deposition in the large shallow Willapa Bay estuary (43 km in length), located in the Columbia River Littoral Cell (CRLC) system (160 km length), was investigated with new vibracores (n=30) and gouge cores (n=8), reaching 2–5 m depth subsurface. Reversing up-core trends of muddy sand to peaty mud deposits in marginal tidal flat settings demonstrate episodic submergence events resulting from cyclic tectonic uplift and subsidence (1–2 m) in the Cascadia subduction zone. These short-term reversals are superimposed on longer-term trends of overall sediment coarsening-up, which represent the transgression of higher-energy sandy tidal flats over pre-existing lower-energy tidal flat mud and peaty mud deposits in late-Holocene time. Fining-up trends associated with channel lateral migration and accretionary bank deposition occurred only infrequently in the broad intertidal flats of Willapa Bay. Vibracores and gouge cores were dated by 14C (n=16) and paleo-subsidence event contacts (n=17). Vibracore median probability 14C ages ranged from 0 to 6,992 yr BP and averaged 2,174 yr BP. Dated sample ages and corresponding depths of tidal flat deposits yield net sedimentation rates of 0.9–1.2 m ka-1, depending on the averaging methods used. Net sedimentation rates in the intertidal flat settings (~1.0 m ka-1) are comparable to the rate of net sea level rise (~1.0 m ka-1), as based on dated paleo-tidal marsh deposits in Willapa Bay. Reported modern inputs of river sand (total=1.77x104 m3 yr-1), from the three small rivers that flow into Willapa Bay, fall well short of the estimated increasing accommodation space (1.9x105 m3 yr-1) in the intertidal (MLLW-MHHW) setting (1.9x108 m2 surface area) during the last 3 ka, or 3.0 m of sea level rise. The under-supply of tributary sand permitted the influx of littoral sand (1.1x105 m3 yr-1) into Willapa Bay, as based on the net sedimentation rate (~1.0 m ka-1) and textural composition (average 60 % littoral sand) in analyzed core sections (n=179). The long-term littoral sand sink in Willapa Bay’s intertidal setting (55 % of total estuary area) is estimated to be about 5 % of the Columbia River supply of sand to the CRLC system, and about 30% relative to the littoral sand accumulated in barrier spits and beach plains during late-Holocene time. A 2.0 m rise in future sea level could yield a littoral sand sink of 2.2x108 m3 in the Willapa Bay intertidal setting, resulting in an equivalent shoreline retreat of 600 m along a 50 km distance of the barrier spit and beach plains that are located adjacent to the Willapa Bay tidal inlet. Willapa Bay serves as proxy for potential littoral sand sinks in other shallow mesotidal estuary-barrier-beach systems around the world following future global sea level rise.
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Corradini, Erica, Daniel Groß, Tina Wunderlich, et al. "Finding Mesolithic Sites: A Multichannel Ground-Penetrating Radar (GPR) Investigation at the Ancient Lake Duvensee." Remote Sensing 14, no. 3 (2022): 781. http://dx.doi.org/10.3390/rs14030781.
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The shift to the early Holocene in northern Europe is strongly associated with major environmental and climatic changes that influenced hunter-gatherers’ activities and occupation during the Mesolithic period. The ancient lake Duvensee (10,000–6500 cal. BCE) has been studied for almost a century, providing archaeological sites consisting of bark mats and hazelnut-roasting hearths situated on small sand banks deposited by the glacier. No method is yet available to locate these features before excavation. Therefore, a key method for understanding the living conditions of hunter-gatherer groups is to reconstruct the paleoenvironment with a focus on the identification of areas that could possibly host Mesolithic camps and well-preserved archaeological artefacts. We performed a 16-channel MALÅ Imaging Radar Array (MIRA) system survey aimed at understanding the landscape surrounding the find spot Duvensee WP10, located in a hitherto uninvestigated part of the bog. Using an integrated approach of high-resolution ground radar mapping and targeted excavations enabled us to derive a 3D spatio-temporal landscape reconstruction of the investigated sector, including paleo-bathymetry, stratigraphy, and shorelines around the Mesolithic camps. Additionally, we detected previously unknown islands as potential areas for yet unknown dwelling sites. We found that the growth rates of the islands were in the order of approximately 0.3 m2/yr to 0.7 m2/yr between the late Preboreal and the Subboreal stages. The ground-penetrating radar surveying performed excellently in all aspects of near-surface landscape reconstruction as well as in identifying potential dwellings; however, the direct identification of small-scale artefacts, such as fireplaces, was not successful because of their similarity to natural structures.
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Hamilton, T. S., Randolph J. Enkin, Michael Riedel, Garry C. Rogers, John W. Pohlman, and Heather M. Benway. "Slipstream: an early Holocene slump and turbidite record from the frontal ridge of the Cascadia accretionary wedge off western Canada and paleoseismic implications." Canadian Journal of Earth Sciences 52, no. 6 (2015): 405–30. http://dx.doi.org/10.1139/cjes-2014-0131.
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Slipstream Slump, a well-preserved 3 km wide sedimentary failure from the frontal ridge of the Cascadia accretionary wedge 85 km off Vancouver Island, Canada, was sampled during Canadian Coast Guard Ship (CCGS) John P. Tully cruise 2008007PGC along a transect of five piston cores. Shipboard sediment analysis and physical property logging revealed 12 turbidites interbedded with thick hemipelagic sediments overlying the slumped glacial diamict. Despite the different sedimentary setting, atop the abyssal plain fan, this record is similar in number and age to the sequence of turbidites sampled farther to the south from channel systems along the Cascadia Subduction Zone, with no extra turbidites present in this local record. Given the regional physiographic and tectonic setting, megathrust earthquake shaking is the most likely trigger for both the initial slumping and subsequent turbidity currents, with sediments sourced exclusively from the exposed slump face of the frontal ridge. Planktonic foraminifera picked from the resedimented diamict of the underlying main slump have a disordered cluster of 14C ages between 12.8 and 14.5 ka BP. For the post-slump stratigraphy, an event-free depth scale is defined by removing the turbidite sediment intervals and using the hemipelagic sediments. Nine 14C dates from the most foraminifera-rich intervals define a nearly constant hemipelagic sedimentation rate of 0.021 cm/year. The combined age model is defined using only planktonic foraminiferal dates and Bayesian analysis with a Poisson-process sedimentation model. The age model of ongoing hemipelagic sedimentation is strengthened by physical property correlations from Slipstream events to the turbidites for the Barkley Canyon site 40 km south. Additional modelling addressed the possibilities of seabed erosion or loss and basal erosion beneath turbidites. Neither of these approaches achieves a modern seabed age when applying the commonly used regional marine 14C reservoir age of 800 years (marine reservoir correction ΔR = 400 years). Rather, the top of the core appears to be 400 years in the future. A younger marine reservoir age of 400 years (ΔR = 0 years) brings the top to the present and produces better correlations with the nearby Effingham Inlet paleo-earthquake chronology based only on terrestrial carbon requiring no reservoir correction. The high-resolution dating and facies analysis of Slipstream Slump in this isolated slope basin setting demonstrates that this is also a useful type of sedimentary target for sampling the paleoseismic record in addition to the more studied turbidites from submarine canyon and channel systems. The first 10 turbidites at Slipstream Slump were deposited between 10.8 and 6.6 ka BP, after which the system became sediment starved and only two more turbidites were deposited. The recurrence interval for the inferred frequent early Holocene megathrust earthquakes is 460 ± 140 years, compatible with other estimates of paleoseismic megathrust earthquake occurrence rates along the subduction zone.
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Häusler, Hermann, Otto Cichocki, Eva Wild, and Peter Steier. "Identification and 14C-dating of Quaternary wood samples dredged from groundwater-filled gravel pits in the UNESCO World Heritage Landscape of Lake Neusiedl (Northern Burgenland, Austria)." Austrian Journal of Earth Sciences 118, no. 1 (2025): 61–73. https://doi.org/10.17738/ajes.2025.0003.
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Abstract In the lowlands of eastern Austria, the Quaternary deposits are underlain by Neogene formations of the Danube/Kisalföld Basin that in turn forms the westernmost bay of the Miocene Central Paratethys. The younger Middle Pleistocene to Holocene deposits of the UNESCO World Heritage Landscape of the Nationalpark “Neusiedler See - Seewinkel” are known as the Illmitz Formation. In the Seewinkel Plain, this formation covers an area of 350 km2 and comprises deposits from a few meters to 20 m thick, which are interpreted as sediments of an anastomosing river system. Youngest fine- grained lacustrine deposits of the Illmitz Formation below salt pans near Podersdorf am See range from ~11 000 calibrated years Before Present (cal BP) to ~8 000 cal BP. Hence also comparable young coarse-clastic channel deposits of the Illmitz Formation were expected. Wood samples dredged from gravel pits in the Seewinkel Plain in the years 1988 and 1996 yielded radiocarbon ages ranging from ~43 600 cal BP to ~32 500 cal BP. In contrast, recently dredged wood remains yielded minimum radiocarbon ages exceeding ~50 000 years. Surprisingly, older deposits of the Seewinkel Plain were dated from both surface of gravel pits and subsurface of salt pans. On the one hand, fine-clastic deposits on top of Seewinkel gravel pits were luminescence dated ~100 to ~55 ka. On the other hand, the deposition of a salt-bearing gravelly silt, the so called “salt-bearing horizon” below salt pans was attributed to MIS 5e (~130 to ~115 ka). Therefore, the wood remains with minimum radiocarbon ages of over 50 000 years probably were deposited in younger channel fills between the salt-bearing horizon and the luminescence dated fine-clastic deposits. Ultimately, it cannot be ruled out that at the base of the Illmitz Formation older wood remains were relocated either from fluvial deposits of paleo-Danube that date back to the Early Pleistocene or from underlying lignite-bearing deposits of Late Neogene. Overall, the multitemporal deposition of woods in climatically changing environments since the beginning of the Rissian glaciation (~MIS 11) may have spanned a period of approximately 400 000 years. Wood anatomical studies allowed identifying several species, among them climatically indifferent taxa as, e.g., Larix/Picea (larch/spruce) and Pinus (pine) as well as thermophilous ones such as Fraxinus (ash), Ulmus (elm) and Quercus (oak). Decimeter-sized dark brown coalified wood residues with rounded edges were dredged from the base of gravel pits. The dark color of wood remains indicates either a completely different chemical environment at the base of the Illmitz Formation or more probably a much longer exposure time in fluvial deposits than for the light brown wood samples.
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He, Feng, Chang Song Lin, and Xiao Qing Zhang. "The Control of Palegeomorphology on Sedimentary Systems in Southeast Qianjiang Depression, Lower Xingouzui Formation, Jianghan Basin." Applied Mechanics and Materials 733 (February 2015): 71–75. http://dx.doi.org/10.4028/www.scientific.net/amm.733.71.
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The pale geomorphology of Lower Xingouzui Formation is controlled by synsedimentary faults. The pale geomorphology controls the distribution of depositional systems, the development of underwater distributary channel controlled by groove and structural slope break belt, combination features of underwater distributary channel and mouth bar controlled by sedimentary slope break, beach bar developed in paleo-uplift, shore-shallow lacustrine and semi-deep lake developed in sag zone.
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Bordy, Emese M., and Orsolya Sztanó. "Badenian (middle Miocene) continental paleoenvironment in the Novohrad–Nógrád Basin (Central Paratethys): a volcano-sedimentary record from the Páris-patak Valley in Hungary." Földtani Közlöny 151, no. 2 (2021): 159. http://dx.doi.org/10.23928/foldt.kozl.2021.151.2.159.
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Two levels of volcaniclastics, comprising conglomerates, sandstones and mudstones, are interbedded with upper middle Miocene (upper Badenian) andesite pyroclastics near the Hungarian-Slovakian border in the distal region of the Central Slovakian Neogene Volcanic Field. Based on the field sedimentological investigations, the facies of the volcaniclastics (e.g., lateral and vertical grain size changes, sedimentary structures, textures, clast composition), their geometry and field relationships are documented herein with the aim of reconstructing the depositional environment. The silica-cemented volcaniclastics are mostly andesite clasts with only ~ 5% being granitoid, quarzitic, and tuff clasts as well as charred fossil wood fragments. The coarse-grained facies association includes crudely stratified, tabular or lenticular, clast-supported pebble-cobble conglomerates with erosive basal surfaces, b-axis imbrication, alternating with sets of cross-bedding. The fine-grained facies association comprises cross-bedded pebbly to medium-grained sandstone and lenses of tuffaceous clayey siltstone with rare horizontal lamination and water-escape structures. Rip-up mudstone clasts, with diametre up to 1 m, are present in both facies associations, revealing the co-existence of abandoned silty palaeo-channel plugs. Facies associations are arranged in several 0.5-4-m-thick, fining-upwards successions that likely formed in shallow channels as downstream- to laterally accreting longitudinal bars, extensive gravel sheets and bars that migrated in peak flow during floods. Palaeocurrent indicators (i.e., clast imbrication, direction of planar cross-bedding, orientation of petrified wood logs) show bedload transport by traction currents, initially towards ~S, and later towards ~W. Intermittently debris flows also occurred. Cross-bedded sandstones formed as in-channel transverse bars during medium/low discharge. Variation of grain size shows frequent discharge fluctuations during permanently wet conditions in the late Badenian. The 4-5-m-deep, low-sinuosity channels were part of a high-energy, gravel-bed braided-river system on the south-eastern foothills of the Lysec palaeo-volcano. Here, pyroclastics were reworked and redeposited as volcaniclastics during inter-eruption, high-discharge episodes.
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ISLAM, Aznarul, Balai Chandra DAS, Nishith Kumar MAJI, and Suman Deb BARMAN. "Assessing meander belt width of Bhagirathi-Jalangi river system in lower Ganga delta, India." European Journal of Geography 11, no. 1 (2020): 140–62. http://dx.doi.org/10.48088/ejg.a.isl.11.1.140.162.
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The present work is an attempt to assess the meander belt width of the river Bhagirathi (frequently oscillating) and river Jalangi (relatively stable) in West Bengal, India based on geospatial data and field data (lithological composition and flow characteristics). Belt width has been computed using four major considerations in increasing order of scale- (i) individual loops of the present channel (MBw1), (ii) maximum loop width of the present channel (MBw2), (iii) palaeo channel characteristics identified through normalized difference water index and pixel-based classification coupled with field observation (MBw3) and (iv) future channel based on the factor of safety which is a space-time averaged safe belt width (MBw4). The study found MBw4 of 11.76 km for Bhagirathi and 6.64 km for Jalangi considering the 100-year factor of safety. The higher meander belt width of Bhagirathi in comparison to Jalangi was found to be correlated with higher monsoon discharge, bed slope, stream power, shear stress, suspended surface sediment concentration, D50, and lower relative bed stability.
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Schultz, Julia A., Rico Schellhorn, Pavel P. Skutschas, et al. "Mammalian petrosal from the Lower Cretaceous high paleo-latitude Teete locality (Yakutia, Eastern Russia)." Vertebrate Zoology 72 (April 15, 2022): 159–68. http://dx.doi.org/10.3897/vz.72.e78479.
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Abstract A mammalian petrosal from the Lower Cretaceous Teete locality in Yakutia (Russia) shows a prominent and complex system of venous channels in the bony wall of the pars cochlearis surrounding the straight cochlear canal. This complex venous system is distinctive and more strongly developed than in other mammalian petrosals. A bony ridge is present on the ventral side of the cochlear canal endocast, continuing from between fenestra vestibuli and fenestra cochleae in anterior direction. This ridge corresponds to the position of the scala tympani, and is similar to the secondary bony lamina of crown therians, but lacks the sharp laminar edge. The fenestra cochleae is separate from the canal for the aquaeductus cochleae (derived), but the fenestra retains a deep sulcus that resembles the perilymphatic sulcus (plesiomorphic). The fenestra cochleae is oval shaped and deep. The straight cochlear canal with a ridge on the ventral side strongly resembles that of eutriconodontans like Priacodon fruitaensis from the Upper Jurassic of North America. However, thick and extensive venous channels in the pars cochlearis are otherwise known from docodontans. In the Teete petrosal the channels are even more developed, and resemble the pattern recently reported from possible haramiyidan petrosals from the Middle Jurassic of western Siberia (Russia). Both eutriconodontan and haramiyidan dental remains are known from the Teete locality beside that of tritylodontids and docodontans.
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Schultz, Julia A., Rico Schellhorn, Pavel P. Skutschas, et al. "Mammalian petrosal from the Lower Cretaceous high paleo-latitude Teete locality (Yakutia, Eastern Russia)." Vertebrate Zoology 72 (April 15, 2022): 159–68. https://doi.org/10.3897/vz.72.e78479.
Full textAbstract:
Abstract A mammalian petrosal from the Lower Cretaceous Teete locality in Yakutia (Russia) shows a prominent and complex system of venous channels in the bony wall of the pars cochlearis surrounding the straight cochlear canal. This complex venous system is distinctive and more strongly developed than in other mammalian petrosals. A bony ridge is present on the ventral side of the cochlear canal endocast, continuing from between fenestra vestibuli and fenestra cochleae in anterior direction. This ridge corresponds to the position of the scala tympani, and is similar to the secondary bony lamina of crown therians, but lacks the sharp laminar edge. The fenestra cochleae is separate from the canal for the aquaeductus cochleae (derived), but the fenestra retains a deep sulcus that resembles the perilymphatic sulcus (plesiomorphic). The fenestra cochleae is oval shaped and deep. The straight cochlear canal with a ridge on the ventral side strongly resembles that of eutriconodontans like Priacodon fruitaensis from the Upper Jurassic of North America. However, thick and extensive venous channels in the pars cochlearis are otherwise known from docodontans. In the Teete petrosal the channels are even more developed, and resemble the pattern recently reported from possible haramiyidan petrosals from the Middle Jurassic of western Siberia (Russia). Both eutriconodontan and haramiyidan dental remains are known from the Teete locality beside that of tritylodontids and docodontans.
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Horozal, Senay, Sujin Chae, Jeong Min Seo, et al. "Quaternary evolution of the southeastern Korean continental shelf, East Sea: Paleo-incised valley and channel systems." Marine and Petroleum Geology 128 (June 2021): 105011. http://dx.doi.org/10.1016/j.marpetgeo.2021.105011.
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Yusubov, N. P., I. S. Guliyev, and Juan I. Soto. "Time and mechanism of formation of mud volcanoes in the South Caspian basin according to seismic data." Azerbaijan Oil Industry, no. 04 (April 15, 2024): 4–14. http://dx.doi.org/10.37474/0365-8554/2024-04-4-14.
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There are 277 mud volcanoes located in the South Caspian basin and the Apsheron-Gobustan periclinal trough and the Lower Kura depression that open to it. On land there are 177 mud volcanic structures, from which steam, water, mud, gas and oil are constantly erupting at approximately 500 points. Mud volcanoes located in the Caspian Sea (about 100) also play an important role in the degassing (mainly methane) of the sedimentary layer of the earth’s crust. Based on the results of geological and geophysical research, it has been established that almost all mud volcanoes discovered on the territory of Azerbaijan are associated with hydrocarbon deposits. In the Oligocene – Lower Miocene, mainly in the Maikop time, a thick clayey stratum (Maikop) - source rocks – accumulated in the South Caspian depression. At the end of the Miocene, there was a sharp drop in erosion levels in this basin. As a result of the activity of several river systems (Pleo-Volga, Paleo-Kura, Paleo-Pirsagat, Paleo-Amu Darya) over the Maikop clay deposits, a system of alternating layers of low and high density was formed with a total thickness of sediments of eight kilometers or more. The Maikop clay formations buried under this multilayer system, possessing the properties of a non-Newtonian fluid, created intrusions in the overlying environment, which at subsequent stages of development of the sedimentation basin became eruptive channels of mud volcanoes. The results of research using 3D seismic data made it possible to identify the mechanism of formation of mud volcanism, which, according to the authors, is associated with the migration of hydrocarbons from oil and gas source rocks to reservoir rocks, with the channels of mud volcanoes being considered as the main migration routes. Geological interpretation of seismic data shows that the formation of mud volcanoes in the South Caspian basin supposedly began from the beginning of the Miocene and continued in parallel during subsequent periods of development of the sedimentation basin. As the thickness of the sedimentary cover increased, mud volcanoes periodically became active.
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Lowe, Ashley L., and John B. Anderson. "Evidence for abundant subglacial meltwater beneath the paleo-ice sheet in Pine Island Bay, Antarctica." Journal of Glaciology 49, no. 164 (2003): 125–38. http://dx.doi.org/10.3189/172756503781830971.
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AbstractMarine-geological and -geophysical data collected from the continental shelf in Pine Island Bay, Antarctica, reveal a complex paleo-subglacial drainage system controlled by bedrock topography and subglacial meltwater discharge. Significant amounts of freely flowing meltwater existed beneath former ice sheets in Pine Island Bay. Subglacial drainage is characterized by descriptions of glacial landforms imaged on the sea floor and sedimentary deposits collected in piston cores. Bedrock geology is characterized using seismic data. Large-scale landforms on the shelf include channels and cavities incised into impermeable crystalline bedrock. There is a transition from randomly oriented channels on the inner shelf to a dendritic pattern of elongate channels on the middle shelf. On the outer shelf, a change in basal conditions occurs where sedimentary deposits bury crystalline bedrock. No evidence for flowing meltwater exists on sedimentary substrates. Instead, meltwater formed at the ice–sediment contact was incorporated into the sediments, contributing to development of a deforming bed, which was sampled in piston cores. Characterization of subglacial meltwater processes that occurred in the past may aid in understanding the role meltwater plays in stability of the West Antarctic ice sheet today.
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St. Clair, James T., Adam R. Mangel, and Tim C. Johnson. "New Insights from Legacy Seismic Data regarding Basalt Elevations and Variability on the Hanford Site." Environmental & Engineering Geoscience 29, no. 2 (2023): 93–104. http://dx.doi.org/10.21663/eeg-d-22-00001.
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Abstract Migration of groundwater contaminants in the Gable Gap area of the Hanford Site in southeastern Washington State is strongly influenced by the distribution and permeability of basalts that lie beneath an unconfined aquifer. Locally, folding and faulting of the Columbia River Basalt associated with the Yakima fold and thrust belt followed by erosion due to the Lake Missoula floods resulted in a complex basalt surface that represents either an impermeable lower boundary to the unconfined aquifer system or localized regions of increased permeability that potentially promote communication between the unconfined aquifer system and deeper, confined aquifer systems. Paleo-channels carved into the basalt by floodwaters are thought to provide preferential flow paths for groundwater contaminants. In 2011, a seismic landstreamer campaign was carried out to image the basalt surface and produced pre-stack depth migrated p-wave reflection images. The reflection images identified two large troughs that may represent paleo-channels and several areas of possible faulting. Here, the streamer data are re-analyzed using refraction travel-time and Rayleigh wave dispersion analyses to obtain images of compressional and shear wave velocities within the suprabasalt sediment sections and the upper basalt surface. The combined interpretation of reflection and seismic velocity images shows complexity in the basalt velocity and elevation, which varies by 50 m or more within the study area. These results, along with other ongoing geophysical investigations, will be used to inform the site geologic model and potentially guide placement of future boreholes needed to quantify vertical flow between the confined and unconfined aquifers.
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Saha, Ujwal Deep, and Soma Bhattacharya. "Reconstructing the channel shifting pattern of the Torsa River on the Himalayan Foreland Basin over the last 250 years." Bulletin of Geography. Physical Geography Series 16, no. 1 (2019): 99–114. http://dx.doi.org/10.2478/bgeo-2019-0007.
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Abstract The varied physiography, incidences of high seasonal discharge, influences of neo-tectonic activity and the young geological foundation with less consolidated cohesive and non-cohesive sediment have left the Himalayan foreland basin a formidable ground, where silt-laden rivers tend to migrate frequently. A set of maps prepared after 1764, space photographs captured in 1970 and current satellite images from 2015 and 2017 were studied to reconstruct the fluvial dynamics of the Torsa River on the foreland basin of Sikkim-Bhutan Himalaya considering a time span of nearly 250 years. Evidence collected from colonial literature, the above-mentioned satellite images and a field survey, were combined to verify results taken from the old maps used as the base of the study. The application of satellite remote sensing and analysis of the topographic signatures of the palaeo-courses in the form of the palaeo-levee, abandoned courses and ox-bow lakes were the major operational attributes in this study. As a consequence of the channel migration of Torsa River since 1764, the historical floodplain of Torsa has been topographically marked by beheaded old distributaries, a misfit channel system and the presence of abandoned segments. Morphometric changes in the old courses, major flood events and neo-tectonic activity guided an overall trend of channel migration eastwards and has led to a couple of channel oscillation events in the Torsa River over the last 250 years. The mechanism of the avulsion events was thoroughly driven by sedimentation-induced channel morphometric changes and occasional high discharge.
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Plan, Lukas, Gottfried Buchegger, Eva Kaminsky, Gabriella Koltai, Tanguy Racine, and Jacek Szczygieł. "Flow regime evolution of a major cave system in the Eastern Alps (Hirlatzhöhle, Dachstein)." International Journal of Speleology 51, no. 3 (2022): 181–91. http://dx.doi.org/10.5038/1827-806x.51.3.2433.
Full textAbstract:
The 116 km-long and 1560 m-deep Hirlatzhöhle is one of the major cave systems in the Northern Calcareous Alps (NCA; Austria). It is located in the NW part of the Dachstein, an extensive karst massif encompassing 576 km² with its highest point at 2995 m a.s.l. In contrast to most other caves in the NCA, Hirlatzhöhle comprises old (epi)phreatic passages located up to 1 km above the base level as well as two modern major drainage systems. The aim of this study is to define the palaeo- and the active flow conditions in combination with speleogenesis, and the age of the cave levels of Hirlatzhöhle. We use morphological as well as sedimentological studies and correlations with other caves. Another difference from cave systems in the NCA is that the majority of passages in Hirlatzhöhle are not developed within the so-called Giant Cave Level between 1200 and 1800 m a.s.l., but deeper between 800 and 1300 m. Most parts of Hirlatzhöhle developed under epiphreatic conditions as indicated by rills and condensation corrosion cupolas, which is the case for much other cave systems in the NCA. In contrast, paragenetic features like canyons and ceiling channels are relatively rare as are insoluble sediments. Elongated scallops indicate that flow velocities were high and abrasive sediments were abundant. Opposite to the nearby Dachstein-Mammuthöhle and other caves east of it that show a west-directed palaeo-flow, scallops in Hirlatzhöhle indicate a NE-directed palaeo-flow and an autogenic recharge. Modern drainage is autogenic and N- to NE-directed as well. Even though burial age dating did not give reasonable results for Hirlatzhöhle yet, the correlation with other adjacent caves suggests a Late Pliocene to Early Pleistocene age of the main palaeo-phreatic level. This is supported by an infinite U-Th age (>0.6 Ma) of a flowstone.
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Zielinski, Gregory A. "Use of paleo-records in determining variability within the volcanism–climate system." Quaternary Science Reviews 19, no. 1-5 (2000): 417–38. http://dx.doi.org/10.1016/s0277-3791(99)00073-6.
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Düsterhus, André, Alessio Rovere, Anders E. Carlson, et al. "Palaeo-sea-level and palaeo-ice-sheet databases: problems, strategies, and perspectives." Climate of the Past 12, no. 4 (2016): 911–21. http://dx.doi.org/10.5194/cp-12-911-2016.
Full textAbstract:
Abstract. Sea-level and ice-sheet databases have driven numerous advances in understanding the Earth system. We describe the challenges and offer best strategies that can be adopted to build self-consistent and standardised databases of geological and geochemical information used to archive palaeo-sea-levels and palaeo-ice-sheets. There are three phases in the development of a database: (i) measurement, (ii) interpretation, and (iii) database creation. Measurement should include the objective description of the position and age of a sample, description of associated geological features, and quantification of uncertainties. Interpretation of the sample may have a subjective component, but it should always include uncertainties and alternative or contrasting interpretations, with any exclusion of existing interpretations requiring a full justification. During the creation of a database, an approach based on accessibility, transparency, trust, availability, continuity, completeness, and communication of content (ATTAC3) must be adopted. It is essential to consider the community that creates and benefits from a database. We conclude that funding agencies should not only consider the creation of original data in specific research-question-oriented projects, but also include the possibility of using part of the funding for IT-related and database creation tasks, which are essential to guarantee accessibility and maintenance of the collected data.