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1
Burnham, Robyn J. "Plant deposition in modern volcanic environments." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 84, no. 3-4 (1993): 275–81. http://dx.doi.org/10.1017/s026359330000609x.
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ABSTRACTVolcanic eruptions and their deposits provide paleobiologists with an array of depositional environments in which to investigate the conditions in which exceptionally preserved flora and fauna are preserved. Studies of vegetation patterns before and after eruptions have shown that tropical vegetation makes a very rapid recovery at the vegetational level (proportion of devastated land covered). The recolonisation of the rare elements of a diversified flora, however, is slow, and so is the rebound of floristic richness, assembled over centuries from surrounding patches of vegetation and from in situ speciation.Two major volcanic events that occurred in the past 15 years were studied in an attempt to understand the processes and complex patterns of plant deposition in volcanic landscapes. Both volcanoes gave rise to terrestrial, andesitic, explosive eruptions that gave little warning of their absolute magnitude or duration. In both eruptions, sediment-dammed lakes were formed in which a large quantity of plant material was trapped. In both instances, forests were killed and both standing and fallen trunks record the composition of the pre-eruption flora. The vegetation present in the vicinity of the volcanoes was, in the case of Mount St Helens (Washington, U.S.A.), dense coniferous forest living in a cool temperate climate and, in the case of El Chichón (Chiapas, Mexico), remnants of paratropical rainforest alternating with patches of agricultural land.Litter layers are present under the tephra at both volcanic sites, yet the pattern of deposition and quality of the plant material differs dramatically between the two, in part because of differences in the types of eruptions and in part because of the nature of the plants available for burial. One of the most significant styles of burial, unexpected in the air-fall ash deposits, is the presence of more than one eruptive layer generated by eruptions only hours apart. These separate eruption layers have different lithological characteristics and the plant deposits buried in the different layers are different in taxonomic composition. Significantly, leaves in the upland volcanic-ash deposits are preserved thus far for 10 years, even in the tropical settings where root growth might be expected to have obliterated all signs of depositional stratigraphy. These impressions and compressions have a high likelihood of entering the fossil record and provide an excellent example of upland deposition and preservation.
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Omoboh, Jonathan Obukowho, Minapuyi I. Odigi, and Kingsley O. Okengwu. "Depositional Processes, Facies and Environment of Deposition of the Upper Miocene (Seravillian/Tortonian) Sediments in the Jokg Field – Eastern Niger Delta." Journal of Scientific and Engineering Research 9, no. 2 (2022): 28–33. https://doi.org/10.5281/zenodo.10510505.
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<strong>Abstract </strong>This work aim to identify the depositional environments of the Seravillian/Tortonian sediments of the coastal swamp depobelt in the Niger Delta basin through the features preserved in the facies by depositional processes. The vertical change in grain size - a product of change in energy of the depositional processes preserved in the identified facies was employed to identify the depositional process (s) that generate the facies. The change in grain size was identified from the gamma ray log trend which have been known to correlate and calibrated with grain size changes. The interval studied within the upper Miocene in the “JOKG” Field, reveals that the sediments were deposited by fluvial processes (erosion, transport, sediment supply and deposition) and shoreline processes (sediment supply, transport, deposition, wave and tidal current redistribution of deposited sediments). The upper section of the interval is dominated by fluvial processes as it contains predominately of sediments which fines upward and sometimes blocky in log trend. The lower part is characterized by sediments which fine downward and coarse upwards with occasional occurrence of sediments that fine upwards. These represents shoreline processes which were occasionally interrupted with fluvial processes. The dominant of the fluvial processes in the upper section show that continental environment occur in the upper section while transitional to shallow marine environment occur in the lower part, since these processes are predominant in these environments respectively. This work thus helps to identify a depositional environment from the predominant of identified processes producing its facies.
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Tavakkoli, Mohammad, Sai R. Panuganti, Francisco M. Vargas, Vahid Taghikhani, Mahmoud Reza Pishvaie, and Walter G. Chapman. "Asphaltene Deposition in Different Depositing Environments: Part 1. Model Oil." Energy & Fuels 28, no. 3 (2013): 1617–28. http://dx.doi.org/10.1021/ef401857t.
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Tavakkoli, Mohammad, Sai R. Panuganti, Vahid Taghikhani, Mahmoud Reza Pishvaie, and Walter G. Chapman. "Asphaltene Deposition in Different Depositing Environments: Part 2. Real Oil." Energy & Fuels 28, no. 6 (2014): 3594–603. http://dx.doi.org/10.1021/ef401868d.
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Hrischeva, E., and S. Gier. "Clay mineralogy and geochemistry of early Jurassic sedimentary rocks from the Moezian Platform, northern Bulgaria." Clay Minerals 37, no. 3 (2002): 413–28. http://dx.doi.org/10.1180/0009855023730053.
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AbstractClay minerals in early Jurassic sequences of shales, siltstones and sandstones deposited in non-marine, transitional and shallow marine environments have been examined by X-ray diffraction, electron microscopy and chemical analysis to study the relationship between clay minerals, their environment of deposition and subsequent diagenetic modifications.The inherited clay mineral composition of the fine-grained sediments reflects the influence of climate, relief, source rocks and depositional processes. Inhomogeneous clay mineral assemblages, comprising abundant kaolinite and varying proportions of illite, I-S, chlorite and vermiculite, characterize fine-grained sediments from the non-marine and transitional environments. In shallow marine depositional environments clay mineral assemblages are more uniform, dominated by illite+I-S with minor kaolinite and chlorite.The principal diagenetic process affecting fine-grained sedimentary rocks is the smectite–illite transformation. In sandstones, the authigenic formation of kaolinite, chlorite and illite appears to have been primarily determined by the environment of deposition.
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Trabucho-Alexandre, J., W. W. Hay, and P. L. de Boer. "Phanerozoic environments of black shale deposition and the Wilson Cycle." Solid Earth 3, no. 1 (2012): 29–42. http://dx.doi.org/10.5194/se-3-29-2012.
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Abstract. The spatial and temporal distribution of black shales is related to the development of environments in which they accumulate and to a propitious combination of environmental variables. In recent years, much has been done to improve our understanding of the mechanisms behind the temporal distribution of black shales in the Phanerozoic and of the environmental variables that result in their deposition. However, the interpretation of ancient black shale depositional environments is dominated by an oversimplistic set of three depositional models that do not capture their complexity and dynamics. These three models, the restricted circulation, the (open) ocean oxygen minimum and the continental shelf models, are an oversimplification of the variety of black shale depositional environments that arise and coexist throughout the course of a basin's Wilson Cycle, i.e. the dynamic sequence of events and stages that characterise the evolution of an ocean basin, from the opening continental rift to the closing orogeny. We examine the spatial distribution of black shales in the context of the Wilson Cycle using examples from the Phanerozoic. It is shown that the geographical distribution of environments of black shale deposition and the position of black shales in the basin infill sequence strongly depend on basin evolution, which controls the development of sedimentary environments where black shales may be deposited. The nature of the black shales that are deposited, i.e. lithology and type of organic matter, also depends on basin evolution and palaeogeography. We propose that in studies of black shales more attention should be given to the sedimentary processes that have led to their formation and to the interpretation of their sedimentary environments.
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Mutshekwa, Thendo, Fulufhelo Mulaudzi, Vuledzani P. Maiyana, Lubabalo Mofu, Linton F. Munyai, and Florence M. Murungweni. "Atmospheric deposition of microplastics in urban, rural, forest environments: A case study of Thulamela Local Municipality." PLOS ONE 20, no. 3 (2025): e0313840. https://doi.org/10.1371/journal.pone.0313840.
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Microplastic (MP) pollution, a pressing environmental issue globally, has received considerable attention in marine, freshwater and terrestrial environments. However, studies on the deposition of airborne MPs, particularly in Southern African regions, have received less attention. As such, the current study aimed at investigating the atmospheric deposition of MPs across three different environments, namely urban, rural and forest in the Thulamela Local Municipality, Limpopo, South Africa. We hypothesised that MP deposition will exhibit significant differences between different environments, with the urban environment having the highest MP deposition fluxes due to the dense population in the area and high human activities. The study results showed that MP deposition fluxes varied significantly across the environments, ranging from 90.51 ± 15.19 – 355.64 ± 47.65 particles/m2/day, with an overall average of 211.87 ± 31.44 particles/m2/day. The highest deposition was recorded in urban environment, while the lowest was observed in the forested environment. The overall deposited MPs were mainly transparent fibres and polyethylene terephthalate (PET). Furthermore, MP deposition found in the forest environment demonstrated a strong positive correlation with rainfall, suggesting that rainfall events play a significant role in the transporting and deposition of MP. The study further shed light on the possible fate of urban and rural atmospheric deposition, which has implications for pristine environments, indicating the transport and potential ecological impacts of MP pollution even in less populated and isolated environments.
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Roy, Supriya. "Environments and processes of manganese deposition." Economic Geology 87, no. 5 (1992): 1218–36. http://dx.doi.org/10.2113/gsecongeo.87.5.1218.
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Lewis, K. L., I. T. Muirhead, A. M. Pitt, A. G. Cullis, G. M. Williams, and T. J. Wyatt‐Davies. "Thin‐film deposition in ultraclean environments." Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films 7, no. 3 (1989): 1413–19. http://dx.doi.org/10.1116/1.576294.
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Ali, Syed Haroon, Osman M. Abdullatif, Lamidi O. Babalola, et al. "Sedimentary facies, depositional environments and conceptual outcrop analogue (Dam Formation, early Miocene) Eastern Arabian Platform, Saudi Arabia: a new high-resolution approach." Journal of Petroleum Exploration and Production Technology 11, no. 6 (2021): 2497–518. http://dx.doi.org/10.1007/s13202-021-01181-7.
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AbstractThis paper presents the facies and depositional environment of the early Miocene Dam Formation, Eastern Arabian platform, Saudi Arabia. Deposition of Dam Formation (Fm.) was considered as a restricted shallow marine deposition. Few studies suggest the role of sea-level change in its deposition but were without decisive substantiation. Here, we describe the facies and high-resolution model of Dam Fm. under varying depositional conditions. The depositional conditions were subjected to changing relative sea level and tectonics. High-resolution outcrop photographs, sedimentological logs, and thin sections present that the mixed carbonate–siliciclastic sequence was affected by a regional tectonics. The lower part of Dam Fm. presents the development of carbonate ramp conditions that are represented by limestones and marl. The depositional conditions fluctuated with the fall of sea level, and uplift in the region pushed the siliciclastic down-dip and covered the whole platform. The subsequent rise in sea level was not as pronounced and thus allowed the deposition of microbial laminites and stromatolitic facies. The southeast outcrops, down-dip, are more carbonate prone as compared to the northwest outcrop, which allowed the deposition of siliciclastic-prone sedimentation up-dip. All facies, architecture, heterogeneity, and deposition were controlled by tectonic events including uplift, subsidence, tilting, and syn-sedimentary faulting, consequently affecting relative sea level. The resulting conceptual outcrop model would help to improve our understanding of mixed carbonate–siliciclastic systems and serve as an analogue for other stratigraphic units in the Arabian plate and region. Our results show that Dam Fm. can be a good target for exploration in the Northern Arabian Gulf.
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Mukhopadhyay, Sanjay Kr, and S. Shome. "Depositional Environment and Basin Development During Early Palaeogene Lignite Deposition, Western Kutch, Gujarat." Journal Geological Society of India 47, no. 5 (1996): 579–92. http://dx.doi.org/10.17491/jgsi/1996/470507.
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Abstract Exploration for lignite by drilling in the early Tertiary Supratrappean paralic sequence on the onshore of western Kutch,Gujarat, provides detailed information on the basement characteristics and palaeoenvironment of lignite deposits. A comprehensive study of outcrop sequence and its dip directional subcrop counterpart reveal that lignite bearing sediments were deposited in three distinct domains; (a) fringe areas of exposed trap rock on mainland, (b) adjacent dip directional subsurface areas on trap basement and (c) areas located beyond the subcrop limit of trap in a basinward direction. Domain (b) is considered most favourable locale for exploration as it contains palaeotopographic lows. A synthesis of outcrop and suberop data helped in identifying three depositional environments for the lignite bearing sediments, namely a prograding delta, back barrier environment and lagoons of foraminiferal bank environments. Vegetation growth and accumulation took place in all the three environments but sizable peat matter are found to occur in transitional lower delta plain, and in the back barrier deposits. These depositional environments and various stratigraphic criteria are used to reconstruct six conceptual models to depict the evolution of early Tertiary basin and accumulation of lignite therein. The significance of stratigraphic markers i.e. Lower Eocene Assilina marl-moll usca coquina bed and the Middle Eocene large Nummulities bed, in locating lignite deposits is also discussed.
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Saleh, Afrah Hassan. "Depositional Environment and Diagenesis processes impact on the carbonate rock quality: a case study, southeastern of Iraq." Iraqi Journal of Science 60, no. 5 (2019): 1104–14. http://dx.doi.org/10.24996/ijs.2019.60.5.19.
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Deposition environment and diagenesis processes are very important factors which affect and control the reservoir properties. The carbonate Mishrif Formation has been selected as a carbonate reservoir in selected wells from southeastern Iraq to understand the influence of the Deposition environment and diagenesis processes on the carbonate reservoir. A core examination of thin sections, shows that Mishrif Formation comprises of six depositional environments, these are: deep marine, lagoon, rudist biostrome, back shoal, and shallow open marine. These environments have effect by many diagenetic processes, including dolomitization, dissolution, micritization, cementation, recrystallization and Stylolite, some of these processes have improved the reservoir properties of the Mishrif reservoir, these are: dissolution, dolomitization and the stylolization. The others diagenetic processes have negative influence on the Petrophysical properties, such as cementation, compaction, and recrystallization processes, which damage the porosity and decrease the pore size. The reservoir properties are controlled by deposition environment, where lagoon environment is mostly compact with low porosity, shoal environment reflects a high energy and grain-supported environment and has good reservoir potential, deep-marine environments consist of mudstone to wackestone, which represents low energy level with low porosity and represents the non-reservoir environment.
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Friday, Uhuo, Kenneth, Okoro, Anthony U., Igwe Ezekiel O., and Ukandu James S. "ANALYSIS OF DEPOSITIONAL ENVIRONMENTS OF UK FIELD RESERVOIR SANDS IN NIGER DELTA BASIN, NIGERIA." American Journal of Applied sciences 04, no. 12 (2022): 05–32. http://dx.doi.org/10.37547/tajas/volume04issue12-02.
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The environments of deposition play a vital role during hydrocarbon formation, migration, trapping and storage. Since the reservoir rocks are a function of their depositional environments, the successful tapping of hydrocarbon from its host rock when wells are drilled depends largely on the petrophysical characteristics of the reservoir rocks which in turn originated from and are influenced by their depositional environment. The reservoir facies in Niger Delta shows a broad range of characteristic sedimentological complexities that gave rise to subsurface geological, drilling and production problems occurring in UK Field. The problems include inaccurate determination of environments of deposition, imperfect stratigraphic correlations and reservoir top uncertainty across the UK Field which are targeted by this research in other to help resolve these challenges facing oil and gas industries in the Niger Delta basin of Nigeria. The research findings will assist in the evaluation of depositional environments and well-to-well lithologic correlation within the UK Field and Niger Delta Basin at large. It will also help to unravel major causes of reservoir top uncertainty in UK Field. Also, it will help in future planning and drilling of new wells within UK Field. The determination of the depositional environments of UK Field reservoir sands were carried out to determine the depositional environment of reservoir sand bodies based on data from seven (7) wells. The determination of depositional environments of sand facies penetrated by wells UK1, UK2, UK3, UK4, UK5, UK6 and UK8 was achieved through a side-by-side comparison of their log suites to standard log motifs. Results of facies analysis showed that the reservoir sands belong to mostly (i) fluvial channel, (ii) barrier bar, (iii) lower-middle shoreface, (iv) distributary mouth bar, (v) distributary channel, (vi) point bar and (vii) tidal channel environments that belonged to parts of a deltaic system. Lithologic correlation result reveals the existence of good correlation among all wells in UK Field due to good geological similarities except well UK8 that failed to correlate perfectly with others thereby establishing the existence of reservoir top uncertainty within UK Field. Therefore, reservoir top uncertainty within UK Field is geologically controlled.
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Ridame, C., J. Dekaezemacker, C. Guieu, S. Bonnet, S. L'Helguen, and F. Malien. "Contrasted Saharan dust events in LNLC environments: impact on nutrient dynamics and primary production." Biogeosciences 11, no. 17 (2014): 4783–800. http://dx.doi.org/10.5194/bg-11-4783-2014.
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Abstract. The response of the phytoplanktonic community (primary production and algal biomass) to contrasted Saharan dust events (wet and dry deposition) was studied in the framework of the DUNE ("a DUst experiment in a low-Nutrient, low-chlorophyll Ecosystem") project. We simulated realistic dust deposition events (10 g m−2) into large mesocosms (52 m3). Three distinct dust addition experiments were conducted in June 2008 (DUNE-1-P: simulation of a wet deposition; DUNE-1-Q: simulation of a dry deposition) and 2010 (DUNE-2-R1 and DUNE-2-R2: simulation of two successive wet depositions) in the northwestern oligotrophic Mediterranean Sea. No changes in primary production (PP) and chlorophyll a concentrations (Chl a) were observed after a dry deposition event, while a wet deposition event resulted in a rapid (24 h after dust addition), strong (up to 2.4-fold) and long (at least a week in duration) increase in PP and Chl a. We show that, in addition to being a source of dissolved inorganic phosphorus (DIP), simulated wet deposition events were also a significant source of nitrate (NO3−) (net increases up to +9.8 μM NO3− at 0.1 m in depth) to the nutrient-depleted surface waters, due to cloud processes and mixing with anthropogenic species such as HNO3. The dry deposition event was shown to be a negligible source of NO3−. By transiently increasing DIP and NO3- concentrations in N–P starved surface waters, wet deposition of Saharan dust was able to relieve the potential N or NP co-limitation of the phytoplanktonic activity. Due to the higher input of NO3− relative to DIP, and taking into account the stimulation of the biological activity, a wet deposition event resulted in a strong increase in the NO3−/DIP ratio, from initially less than 6, to over 150 at the end of the DUNE-2-R1 experiment, suggesting a switch from an initial N or NP co-limitation towards a severe P limitation. We also show that the contribution of new production to PP strongly increased after wet dust deposition events, from initially 15% to 60–70% 24 h after seeding, indicating a switch from a regenerated-production based system to a new-production based system. DUNE experiments show that wet and dry dust deposition events induce contrasting responses of the phytoplanktonic community due to differences in the atmospheric supply of bioavailable new nutrients. Our results from original mesocosm experiments demonstrate that atmospheric dust wet deposition greatly influences primary productivity and algal biomass in LNLC environments through changes in the nutrient stocks, and alters the NO3−/DIP ratio, leading to a switch in the nutrient limitation of the phytoplanktonic activity.
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Saša, Ivanišević, and Radivojević Dejan. "Upper Miocene depositional environments of the Kikinda-Mokrin High (Serbia)." Interpretation 6, no. 1 (2018): SB65—SB76. http://dx.doi.org/10.1190/int-2017-0084.1.
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Exploration for oil and gas in mature areas, such as the Pannonian Basin, can benefit from reexamination of old data using more advanced modern workflows that focus on the temporal and spatial aspects of sediment deposition. Specifically, we apply a new environment of deposition model that interprets the Upper Miocene-Pliocene sediments as being deposited in a rapidly filling basin characterized by quick shelf edge progradation from the northwest toward the southeast. Reconstruction of this shelf edge trajectory reveals the absence of a Lake Pannon level drop during this time; rather, deposition was done during a highstand systems tract. We divided the Serbian postrift sediments into the Hetin, Majdan, Mokrin, Kikinda, and Paludina Formations used by geoscientists in Hungary and Slovakia. Hemipelagic marls of the Hetin Formation serve as the source rocks for the Majdan Formation basin-center turbidite reservoirs. These turbidite reservoirs are in turn sealed by clays and marls of the Mokrin slope formation. In contrast to previous interpretations of this part of the basin, our new sequence stratigraphy interpretation of the depositional environment interpretation significantly reduces the miscorrelation of the target sandstone reservoirs. Application of this sequence stratigraphy model also promises a better understanding of the other elements of the hydrocarbon system, which should lead to better production performance and reservoir management.
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Friis, Henrik. "The role of faecal pellets in deposition of marine muddy sediments - examples from the Danish Tertiary." Bulletin of the Geological Society of Denmark 42 (October 31, 1995): 68–73. http://dx.doi.org/10.37570/bgsd-1995-42-07.
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The deposition of muds may take place in various types of aggregates and pellets. In some environments this form of sedimentation has been described as important in the formation of the sediment, but very often the aggregated character of the sediment is completely lost by subsequent bioturbation, compaction or diagenesis. The paper describes examples from Danish Tertiary formations, where very early cementation by calcite or pyrite stabilized the sediment and preserved the sandy character of the muddy sediments. One example is an Oligocene shallow water lagoonal heterolith, where the mud laminae are actually well sorted pellet sand. Another example is a Paleocene hemipagic shelf mud, which in early cemented parts consist of porous pellet sand. Outside the cemented area the pelleted character is seen to disappear due to compaction. The examples demonstrate, that possible deposition of mud in high energy environments as pellets and aggregates should be considered when depositional environments are inferred.
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Kontopoulos, Nikolaos, and Avraam Zelilidis. "Depositional processes in outer arc marginal sib-basins during the Messinian time; Messinian crisis: An example from western Crete Island, Greece." Geologica Balcanica 27, no. 1-2 (1997): 91–10. http://dx.doi.org/10.52321/geolbalc.27.1-2.91.
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The ratio of sea-level falling rate to subsidence/uplift rate was the master factor controlling the evolution of three adjacent marginal sub-basins, the Platanos, Kastelli and Maleme Sub-Basins. During the Messinian, the Platanos Sub-Basin was characterized by a constant shelf environment with a water depth of deposition not more than 50 m; a sabkha environment which changed during the latest Messinian to a shelf environment characterized the Kastelli Basin, representing a water depth of deposition changing from 0 m to less than 50 m; fmally, a terrestrial environment which changed during the latest Messinian to a shallow marine environment, characterized the Maleme Basin, representing a sea-level rise of no more than 50 m. The evolution of the depositional environments in the three adjacent basins suggests: a. A total sea-level fall of >250 m from latest Tortonian to latest Messinian time in the western Crete (>200 m during latest Tortonian and 50 m during Early Messinian). b. When the ratio of sea-level falling rate to subsidence/uplift rate is > 1, lake or shallow marine environments (shelf) changed to terrestrial, and outer slope environments changed to shelf environment. When the ratio is slightly > 1 a shelf environment changes to a sabkha; and when it equals 1, the depositional environment changes from a sabkha or terrestrial to shelf environment. c. Depositional environments characterized by lowstand conditions during the Messinian time.
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Hoff, H. A., A. A. Morrish, J. E. Butler, and B. B. Rath. "Comparative fractography of chemical vapor and combustion deposited diamond films." Journal of Materials Research 5, no. 11 (1990): 2572–88. http://dx.doi.org/10.1557/jmr.1990.2572.
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Polycrystalline diamond films of several thicknesses have been fractured by manual bending and examined by scanning electron microscopy. These films have been deposited in controlled environments at low pressures by chemical vapor deposition and in ambient atmosphere with an oxygen-acetylene torch. Fracture surfaces in the low pressure depositions exhibit cleavage steps across the grains. These surfaces, independent of thickness, are primarily transgranular, attesting to the inherent strength of the deposits. However, the ambient deposited diamond has primarily intergranular fracture indicative of weak grain boundaries. Internal defects, observed with transmission electron microscopy, such as twins, stacking faults, and dislocations, occur generally in both types of deposition with no apparent preference for location or type of deposition.
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RATCLIFFE, K. T., and A. T. THOMAS. "Carbonate depositional environments in the late Wenlock of England and Wales." Geological Magazine 136, no. 2 (1999): 189–204. http://dx.doi.org/10.1017/s0016756899002538.
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Based on outcrop studies and borehole data, six bedded lithofacies and two reef types are recognized within the Much Wenlock Limestone Formation of the English Midlands and Welsh Borderland. The lithofacies are interpreted to represent a series of carbonate shelf environments extending from below storm wave-base to well above fair weather wave-base. In common with many other shallow marine carbonate depositional systems, the principal controls on lithofacies development were hydrodynamic energy, the supply of fine clastic sediment, and patterns of colonization of the sea floor by organisms. Reef distribution was probably controlled by the nature of the substrate, water circulation, and rate of siliciclastic sedimentation. A depositional model is proposed which incorporates biostratigraphical evidence suggesting that the formation youngs to the west on the northern part of the shelf. Deposition of the Much Wenlock Limestone Formation there began in the West Midlands, where 12 m of microbial limestone were lain down in a mid-shelf setting during a local regression. The remainder of the shelf was dominated by low energy siliciclastic deposition at that time. The West Midlands then returned to somewhat deeper water, lower energy deposition, the resulting impure calcareous muds becoming diagenetically changed into the nodular limestone lithofacies. That lithofacies is commonly overlain successively by the interbedded limestone and silty mudstone lithofacies, and then the crinoidal grainstone lithofacies. This vertical lithofacies sequence is uniform over the entire northern part of the shelf, reflecting a gradual decrease in water depth. The crinoidal grainstone lithofacies was deposited as a wave-influenced carbonate sandbody which prograded from east to west. Lithofacies sequences on the southern shelf are laterally impersistent, probably due to greater tectonic instability and topographical variablity.
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Htwe, Paike, Sugeng Sapto Surjono, Donatus Hendra Amijaya, and Kyuro Sasaki. "DEPOSITIONAL MODEL OF NGRAYONG FORMATION IN MADURA AREA, NORTH EAST JAVA BASIN, INDONESIA." Journal of Applied Geology 7, no. 2 (2015): 51. http://dx.doi.org/10.22146/jag.26947.
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The early Middle Miocene Ngrayong Formation, an important reservoir of North East Java Basin, is well exposed in the central anticlinal part of Madura Island. The purpose of current study is to classify the depositional environments of the study area based on the characteristics and geometry of sedimentary facies. In the Madura island, the thicker clastics and deeper carbonates of Ngimbang Formation and Kujung Formation of Late Oligocene-Early Miocene deposited in the northeast-southwest asymmetrical half grabens. After the deposition of Kujung Formation, the basin morphology developed nearly eastwest trending shelf edge and the deposition of Tuban Formation began. The fine grained complex of Tuban Formation was followed by the Ngrayong Sandstones deposition. The depositional model of Ngrayong Formation is being producing of wide variety of depositional environments. Large scale cross-bedded sandstones and bioturbated massive sandstones with thin to medium bedded argillaceous limestone that outcrop in the northern part of the study area are deposited in costal environment. The heterolithic sandstone with planar and trough cross-lamination, fine grained sandstone with interlaminated structure and bioclastic carbonate exposed in the central part of the study area are deposited in upper shallow marine area. Dark grey siltstones and mudstones deposited in lower shallow marine area are well exposed in southern part of the study area. In conclusion, Ngrayong Formation in Madura area is developed in three depositional units which are coastal, upper shallow marine and lower shallow marine.
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Newman, J., P. Su, and G. Yee. "Smoke Deposition Velocity in Industrial Fire Environments." Fire Safety Science 10 (2011): 655–68. http://dx.doi.org/10.3801/iafss.fss.10-655.
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Golfinopoulos, Vasilis, David J. W. Piper, Avraam Zelilidis, et al. "Depositional Environments and Soft Sediment Deformation in the Early Jurassic Ammonitico Rosso Formation of Western Greece." Geosciences 15, no. 1 (2025): 10. https://doi.org/10.3390/geosciences15010010.
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This study investigates the depositional environments and soft sediment deformation within the Early Jurassic Ammonitico Rosso Formation in the External Ionian Basin (Western Greece), focusing on its biostratigraphy, sedimentology, and tectonic activity. This research provides new insights into the depositional environment of the Ammonitico Rosso Formation and its transitions with the underlying and overlying formations. Syn-rift tectonics at the time of deposition formed half-grabens, which influenced sedimentary processes and created conditions for seabed slumping. Detailed field mapping and microfacies analysis revealed two distinct depositional environments: deep-water to open-shelf settings and platform-margin reefs. The entire Ammonitico Rosso Formation is allochthonous, deposited as repetitive slices of little-disturbed stratified sediments capped by debrites near the toe of a complex submarine landslide. The presence of well-preserved fossils, such as planktonic and benthic foraminifera, Radiolaria (both Spumellaria and Nassellaria), and ammonites, allowed precise age determinations, suggesting that the first appearance of Globuligerina might predate previous records, occurring first in the Pliensbachian rather than the Toarcian. These findings contribute to the ongoing debate on the depth and conditions of Ammonitico Rosso deposition, supporting the hypothesis of a relatively deep, open-shelf environment influenced by slope instability.
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Channing, Alan, and Dianne Edwards. "Experimental taphonomy: silicification of plants in Yellowstone hot-spring environments." Transactions of the Royal Society of Edinburgh: Earth Sciences 94, no. 4 (2003): 503–21. http://dx.doi.org/10.1017/s0263593300000845.
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ABSTRACTDuring experiments conducted within the vent pool of Medusa Geyser, Norris Geyser Basin, Yellowstone National Park, USA, amorphous opaline silica (opal-A) was deposited on/within plant tissues within 30 days of immersion. Initially, deposition created inter/intra-cellular films which lined cell walls plus intercellular colloid suspensions (sols) of opal-A nano/microspheres. By 330 days, opal-A deposition created a robust external and internal matrix that stabilised tissues against collapse and replicated plant structure. Opal-A films increased to micron-order thicknesses and intracellular sols were created. Systematic variation of opal-A fabric between tissues comprising living/dead cells at the time of deposition indicate that cell function, architecture and shape influence fabric development. Heterogeneity of opal-A fabric within adjacent cells of similar structure/function indicates spatially/temporally fluctuating physicochemical conditions and the presence of intraorganic microenvironments. Early deposition of opal-A films suggests a period of low silica supersaturation and slow opal-A deposition. In contrast, intracellular sols suggest high levels of supersaturation, and rapid opal-A deposition. Shell-like microsphere growth suggests cyclic variation of silica supersaturation, and alternations between rapid and slower opal-A deposition. Microsphere growth to the upper limit of colloidal stability and colloidal crystal structures indicate prolonged sol stability, whilst floc-like microsphere networks indicate localised sol instabi
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Iwaoka, Kazuki, Masahiro Hosoda, Shinji Tokonami, Eliza B. Enriquez, Lorna Jean H. Palad, and Reiko Kanda. "DEVELOPMENT OF CALCULATION TOOL FOR RESPIRATORY TRACT DEPOSITION DEPENDING ON AEROSOLS PARTICLE DISTRIBUTION." Radiation Protection Dosimetry 184, no. 3-4 (2019): 388–90. http://dx.doi.org/10.1093/rpd/ncz074.
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Abstract Inhalation exposures occur by inhaled radioactive nuclides depositing in the various locations in the respiratory tract (International Commission on Radiological Protection Publication 66). Respiratory tract deposition depends on particle size. The sensitivity to ionising radiation is different among respiratory regions. Under actual atmospheric environments, the radionuclides attach to aerosols of various size in the atmosphere, so the particle size of radionuclides changes differently. Therefore, it is important for the estimation of health impact to calculate the respiratory tract deposition under atmospheric environment wherein the various sizes of radioactive nuclides (i.e. polydisperse particles) exists. In this study, a tool which can calculate the respiratory tract deposition on the basis of polydisperse particle size distribution was developed to estimate dose depending on variable aerosol particle sizes.
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Wang, Jin, Milan Vujanovic, and Bengt Sunden. "A review of multiphase flow and deposition effects in film-cooled gas turbines." Thermal Science 22, no. 5 (2018): 1905–21. http://dx.doi.org/10.2298/tsci180108258w.
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This paper presents a review of particle deposition research in film-cooled gas turbines based on the recent open literature. Factors affecting deposition capture efficiency and film cooling effectiveness are analyzed. Experimental studies are summarized into two discussions in actual and virtual deposition environments. For investigation in virtual deposition environments, available and reasonable results are obtained by comparison of the Stokes numbers. Recent advances in particle deposition modeling for computational fluid dynamics are also reviewed. Various turbulence models for numerical simulations are investigated, and solutions for treatment of the particle sticking probability are described. In addition, analysis of injecting mist into the coolant flow is conducted to investigate gas-liquid two-phase flow in gas turbines. The conclusion remains that considerable re-search is yet necessary to fully understand the roles of both deposition and multi-phase flow in gas turbines.
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Dinis, Maria de Lurdes, and Maria Inês Gonçalves. "Spatial Variability of Atmosphere Dust Fallout Flux in Urban–Industrial Environments." Atmosphere 11, no. 10 (2020): 1069. http://dx.doi.org/10.3390/atmos11101069.
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This work aimed to assess and characterize the air quality in what concerns particulate pollution in urban–industrial environments. The main objectives were to study the spatial variability of the deposition flux of particulate pollution identifying areas with higher deposition and to associate the variability with climatological variables and with possible surrounding emitting sources. The method for collecting the deposited particles was based on the standard NF X 43–007. Sampling for particulate pollution took place between April 2015 and February 2016 through seven sampling campaigns. Maps of the spatial dispersion for the particulate pollution were obtained through statistics and geostatistics techniques. Elemental identification by scanning electron microscopy (SEM) was also used but only in two sampling campaigns. The results show that the sampling campaigns that took place during hot and dry periods, 2nd and 3rd, present higher deposition flux: 2.04 g/(m2 × month) and 1.72 g/(m2 × month), respectively. Lower deposition fluxes were registered in the 6th and 7th campaigns: 0.23 g/(m2 × month) and 0.24 g/(m2 × month), respectively. A recurrent high deposition was also observed at specific sampling points that may be due to both the nearby road traffic and the presence of chimneys. SEM analysis allowed to associate repetitive element deposition, at the same sampling point, to the same emitting source.
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Abdullah, W. H., D. Murchison, J. M. Jones, N. Telnaes, and J. Gjelberg. "Lower carboniferous coal deposition environments on Spitsbergen, Svalbard." Organic Geochemistry 13, no. 4-6 (1988): 953–64. http://dx.doi.org/10.1016/0146-6380(88)90277-x.
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Lézine, A.-M., and T. M. Edorh. "Modern pollen deposition in West African Sudanian environments." Review of Palaeobotany and Palynology 67, no. 1-2 (1991): 41–58. http://dx.doi.org/10.1016/0034-6667(91)90015-u.
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Millward, G. R., H. E. Evans, I. P. Jones, and C. D. Eley. "Carbon deposition on stainless steel in oxidising environments." Materials at High Temperatures 20, no. 4 (2003): 535–41. http://dx.doi.org/10.1179/mht.2003.062.
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Gao, N. P., and J. L. Niu. "Modeling particle dispersion and deposition in indoor environments." Atmospheric Environment 41, no. 18 (2007): 3862–76. http://dx.doi.org/10.1016/j.atmosenv.2007.01.016.
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Nelson, David M., Urumu Tsunogai, Dong Ding, et al. "Triple oxygen isotopes indicate urbanization affects sources of nitrate in wet and dry atmospheric deposition." Atmospheric Chemistry and Physics 18, no. 9 (2018): 6381–92. http://dx.doi.org/10.5194/acp-18-6381-2018.
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Abstract. Atmospheric nitrate deposition resulting from anthropogenic activities negatively affects human and environmental health. Identifying deposited nitrate that is produced locally vs. that originating from long-distance transport would help inform efforts to mitigate such impacts. However, distinguishing the relative transport distances of atmospheric nitrate in urban areas remains a major challenge since it may be produced locally and/or be transported from upwind regions. To address this uncertainty we assessed spatiotemporal variation in monthly weighted-average Δ17O and δ15N values of wet and dry nitrate deposition during one year at urban and rural sites along the western coast of the northern Japanese island of Hokkaido, downwind of the East Asian continent. Δ17O values of nitrate in wet deposition at the urban site mirrored those of wet and dry deposition at the rural site, ranging between ∼ +23 and +31 ‰ with higher values during winter and lower values in summer, which suggests the greater relative importance of oxidation of NO2 by O3 during winter and OH during summer. In contrast, Δ17O values of nitrate in dry deposition at the urban site were lower (+19 – +25 ‰) and displayed less distinct seasonal variation. Furthermore, the difference between δ15N values of nitrate in wet and dry nitrate deposition was, on average, 3 ‰ greater at the urban than rural site, and Δ17O and δ15N values were correlated for both forms of deposition at both sites with the exception of dry deposition at the urban site. These results suggest that, relative to nitrate in wet and dry deposition in rural environments and wet deposition in urban environments, nitrate in dry deposition in urban environments forms from relatively greater oxidation of NO by peroxy radicals and/or oxidation of NO2 by OH. Given greater concentrations of peroxy radicals and OH in cities, these results imply that dry nitrate deposition results from local NOx emissions more so than wet deposition, which is transported longer distances. These results illustrate the value of stable isotope data for distinguishing the transport distances and reaction pathways of atmospheric nitrate pollution.
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Khuong, Hung The, and Tra Thuy Thi Lai. "Studies on lithofacies sequences in the Hoanh Bo basin, Quang Ninh province by using Markov chain model and Entropy function." Journal of Mining and Earth Sciences 63, no. 1 (2022): 15–26. http://dx.doi.org/10.46326/jmes.2022.63(1).02.
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The succession of lithofacies in the Dong Ho and Tieu Giao formation's Hoanh Bo basin was statistically analyzed using the modified Markov chain model and the function of Entropy. Based on the field definitions, petrographic investigation, and their borehole logs, the lithofacies study was carried out to determine the sediment deposition system and the deposition environment. Seventeen sub - lithofacies organized within the succession are recognized in three lithofacies associations. The analysis result of the Markov chain and chi-square or X2 test indicates that the deposition of the lithofacies is a non - markovian process and represents cyclic deposition of asymmetric fining - upward. To evaluate the randomness of the occurrence of lithofacies in a succession, entropy analysis was performed. Each state is associated with two types of entropy; one is relevant to the Markov matrix expressing upward transitions (entropy after deposition) and the other is relevant to the downward transition matrix (entropy before deposition). The energy regime calculated from the maximum randomness entropy analysis indicates that changing patterns in a deposition has resulted from rapid to steady flow. This results in a change in the depositional pattern from alluvial - fluvial to lacustrine environments, specifically from conglomerate facies (A1) → sandstone facies (A2)→ fine-grained and non - debris facies (A3).
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Wendt, Anna K., Mike A. Arthur, Rudy Slingerland, Daniel Kohl, Reed Bracht, and Terry Engelder. "Geochemistry and depositional history of the Union Springs Member, Marcellus Formation in central Pennsylvania." Interpretation 3, no. 3 (2015): SV17—SV33. http://dx.doi.org/10.1190/int-2014-0228.1.
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Debate continues over paleoenvironmental conditions that prevail during deposition of organic-carbon (C)-rich marine source rocks in foreland basins and epicontinental seas. The focus of disagreement centers largely on paleowater depth and the prevalence of anoxia/euxinia. The issues of paleodepth and water column conditions are important for prediction of lateral variations in source quality within a basin because the viability of a hydrocarbon play depends on a thorough understanding of the distribution of source rock quality and depositional environments. We used inorganic geochemical data from the Middle Devonian Marcellus Shale in the Appalachian Basin to illustrate interpretive strategies that provided constraints on conditions during deposition. Source evaluation typically relies on the analysis and interpretation of organic geochemical indicators, potentially also providing evidence of the degree of thermal maturity and conditions of the preservation of the organic matter. The Marcellus Formation is thermally mature, making the evaluation of the organic-carbon fraction for geologic interpretation inadequate. Because most labile organic matter has largely been destroyed in the Marcellus Formation, analysis of inorganic elements may be used as an alternative interpretative technique. Several inorganic elements have been correlated to varying depositional settings, allowing for their use as proxies for understanding the paleodepositional environments of formations. A high-resolution geochemical data set has been constructed for the Union Springs Member along a transect of cores from proximal to distal in the Appalachian Basin in central Pennsylvania using major, minor, and trace elemental data. Our results suggested that during deposition, the sediment-water interface, and a portion of the water column, was anoxic to euxinic. As deposition continued, euxinia was periodically interrupted by dysoxia and even oxic conditions, and a greater influx of clastic material occurred. Such variations were likely related to fluctuations in water depth and progradation of deltaic complexes from the eastern margin of the Appalachian Basin.
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Mauney, Jack. "Carbon Allocation in Cotton Grown in CO2 Enriched Environments." Journal of Cotton Science 20, no. 3 (2016): 232–36. http://dx.doi.org/10.56454/wydi3746.
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Many studies have used CO2 -enriched environments to identify the factors limiting growth and productivity of the cotton crop. This review focuses on the allocation of carbohydrates within the plant in these environments. Three pools of carbohydrates have been shown to be altered significantly by CO2 enrichment. 1) Leaf starch is increased during the day and mobilized for night utilization; 2) starch deposition in the stems increases during the juvenile period of growth and is utilized during the boll filling period, and 3) starch deposition is increased in roots during the juvenile and early fruiting period. This enables the roots to remain more active during the heavy demand of fruit maturation. The expansion of these three pools of deposition enables the cotton crop to utilize the higher photosynthetic rate to a greater degree than other crops. The activity in these pools determines the growth and productivity of the crop at ambient CO2.
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Allen, Wai K., Kenneth D. Ridgway, J. A. Benowitz, et al. "Neogene sedimentary record of the evolution of a translated strike-slip basin along the Denali fault system: Implications for timing of displacement, composite basin development, and regional tectonics of southern Alaska." Geosphere 18, no. 2 (2022): 585–615. http://dx.doi.org/10.1130/ges02435.1.
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Abstract Analysis of the late Miocene to Holocene McCallum sedimentary basin, located along the south side of the eastern Denali fault system, provides a better understanding of strike-slip basin evolution, timing of displacement on the Denali fault, and tectonics of the southern Alaska convergent margin. Analysis of the McCallum basin utilizing measured stratigraphic sections, lithofacies analyses, and 40Ar/39Ar tephra ages documented a 564-m-thick, two-member stratigraphy. Fine-grained, lacustrine-dominated environments characterized deposition of the lower member, and coarse-grained, stream-dominated alluvial-fan environments characterized deposition of the upper member. The 40Ar/39Ar dating of tephras indicated that the lower member was deposited from 6.1 to 5.0 Ma, and the upper member was deposited from 5.0 to 3.8 Ma. Our stratigraphic analysis of the McCallum basin illuminates the development of a composite strike-slip basin, with the deposition of the lower member occurring along a transtensional fault section, and deposition of the upper member occurring along a transpressional fault section. This change in depositional and tectonic settings is interpreted to reflect ~79–90 km of transport of the basin along the Denali fault system based on Pleistocene–Holocene slip rates. Previous studies of the timing of Cenozoic displacement on the Denali fault system utilizing sedimentary records emphasized a Paleogene component; our findings, however, also require a significant Neogene component. Neogene strike-slip displacement and basin development along the Denali fault system were broadly coeval with development of high topography and related clastic wedges across southern Alaska in response to flat slab subduction of the Yakutat microplate.
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Woolfe, Ken J. "Devonian depositional environments in the Darwin Mountains: Marine or non-marine?" Antarctic Science 5, no. 2 (1993): 211–20. http://dx.doi.org/10.1017/s0954102093000276.
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The depositional environment of the Devonian Taylor Group has been subject to considerable debate for over 30 years. The debate stems largely from a belief that the abundant and diverse trace fossils represent a marine ichnofauna, whereas sedimentary features, including palaeosols, desiccation polygons and red beds, are more typical of a non-marine setting. The debate is reconciled by a reinterpretation of the trace fossil assemblage which shows that the trace fossils comprise a typical fresh water (Scoyenia ichnofacies) assemblage, and their occurrence in the Taylor Group in the Darwin Glacier area is entirely consistent with deposition in a mixed fluvial-lacustrine-subaerial environment.
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van Setten, E., T. M. Gür, D. H. A. Blank, J. C. Bravman, and M. R. Beasley. "Miniature Nernstian oxygen sensor for deposition and growth environments." Review of Scientific Instruments 73, no. 1 (2002): 156–61. http://dx.doi.org/10.1063/1.1424906.
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ZHAO, B., and J. WU. "Particle deposition in indoor environments: Analysis of influencing factors." Journal of Hazardous Materials 147, no. 1-2 (2007): 439–48. http://dx.doi.org/10.1016/j.jhazmat.2007.01.032.
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Pannozzo, Natascia, Rachel K. Smedley, Andrew J. Plater, Iacopo Carnacina, and Nicoletta Leonardi. "Novel luminescence diagnosis of storm deposition across intertidal environments." Science of The Total Environment 867 (April 2023): 161461. http://dx.doi.org/10.1016/j.scitotenv.2023.161461.
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Bharti, Gupta Ramakant Maurya. "Metalliferous uptake and Deposition in Fish in contaminated environments." Journal of Wildlife and Biodiversity 8, no. 2 (2024): 103–21. https://doi.org/10.5281/zenodo.11097725.
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There is an accumulation of toxic metal ions in an aquatic habitat that modifies the physical and chemical characteristics of water, posing a threat to aquatic organisms. The fish's body absorbs heavy metals through the gills, dorsal surface, and gastrointestinal system when they eat foodstuff that has high levels of these metals. Zinc, Lead, Mercury, Copper, Arsenic, Nickel, chromium and cadmium are the primary heavy metal contaminants responsible for inducing toxicity in fish. Oxidative stress, or oxidative damage, is the primary chemical process responsible for metal poisoning. Stress undermines a low immune system, leading to harm to organs and tissues, developmental irregularities, and reduced reproductive capacity. Due to the copious availability of vitamins, proteins, and fatty acids such as omega-3 found in fish, individuals are inclined to consume seafood as their primary nutritional source. Consequently, the aggregation of toxic metallic elements in fish tissues has a direct impact on people, causing detrimental effects that accelerate the onset of various diseases. To effectively enforce aquatic conservation regulations and protect human lives, it is imperative to investigate the origins of toxic metals and their detrimental effects on the health of fish.
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Ndukwe, O. S., G. J. Udom, and C. U. Ugwueze. "Lithofacies control on depositional environments in shallow offshore Niger Delta: implication on reservoir quality." Scientia Africana 21, no. 2 (2022): 59–74. http://dx.doi.org/10.4314/sa.v21i2.7.
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The KEN field lies within latitude 4⁰52ꞌ44ꞌꞌ N to 4⁰53'04'' N and 6⁰22'50'' E to 6⁰22'26'' E. The geological and geophysical data sets were used to describe reservoir depositional facies and their environment of deposition. A detailed and accurate environment of sediment delineation is a solid basis to enhance characterization and providing measures for improving hydrocarbon reservoirs. This study aims to presents an effective method for accurately defining depositional environment with different data sets. The data used comprises of biostratigraphy, well logs from three wells and 3D full angle stack seismic data. The biostratigraphic data help to ascertain the age of the formation delineated to be middle Miocene to late Miocene based on the marker shale. It also helps in picking the stratigraphic surfaces. Three depositional sequences were delineated and dated with maximum flooding surfaces of 15.0, 12.6 and 11.5 Ma, respectively. Log sequence analysis reveals the internal geometry and stacking pattern of the mapped sequences. The gamma ray signature varies from serrated cylindrical, funnel to the bell-shaped log motif. The seismic stratigraphy involved facies analysis and reflection termination patterns, which aided the mapping of depositional sequence. The internal geometry is composed of Highstand, transgressive, and lowstand systems tracts. The stacking patterns vary from progradational, aggradational and retrogradational. Based on the seismic facies analysis, the integrated results show that the field of study is of pelagic and debris flow origin deposited in shallow marine settings, which also conform with the other data sets used for this study. The depositional environment of the three delineated reservoirs (Reservoir A, B and C) vary from deltaic upper to lower shoreface channels sand. Reservoir C, which is laterally continuous across the three studied wells shows that the connectivity of reservoir C is loosely amalgamated. The integrated data used for this study indicate that the environment of deposition varies from inner neritic to outer neritic environment. The results of this research are essential for reservoir quality, exploration, appraisal and development phases.
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Nayak, Ganapati Narayan. "Changing Tropical Estuarine Sedimentary Environments with Time and Metals Contamination, Cest Coast of India." Journal of The Indian Association of Sedimentologists 38, no. 2 (2021): 63–78. http://dx.doi.org/10.51710/jias.v38i2.141.
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Estuaries are one of the major sub-environments of the coastal zone wherein freshwaters interact and mix with saline waters, and facilitate deposition of finer sediments, organic matter, and metals. Intertidal mudflat and mangrove sediment cores collected from estuaries along the central west coast of India were investigated for various sedimentological and geochemical parameters to understand the changes in the sedimentary depositional environments and various factors influencing the processes. Additionally, estuarine biota was examined to understand the bioaccumulation of metals with respect to bioavailability. The results indicated considerable changes in the depositional environments with time owing to sea-level changes; geomorphology of the estuaries; rainfall and river runoff; anthropogenic activities including construction of dams and bridges. The sediments in the estuaries are considerably polluted by metals and pose toxicity risks to the estuarine biota due to high metal bioavailability. Marine gastropods and mangrove plants act as prospective bio-indicators, and the bioremediation potential of mangroves for contaminated sediments was identified. Metal bioaccumulation in edible benthic biota can be harmful to the human health.
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Spiro, C. L., S. G. Kimura, and C. C. Chen. "Ash Behavior During Combustion and Deposition in Coal-Fueled Gas Turbines." Journal of Engineering for Gas Turbines and Power 109, no. 3 (1987): 325–30. http://dx.doi.org/10.1115/1.3240043.
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Chemical and physical transformations of coal ash during combustion and deposition in gas turbine environments have been studied. Extensive characterization of the coal-water mixture fuel and deposits obtained on deposition pins and turbine nozzle vanes has been performed. The behavior of alkali metals has been found to be much different from that for petroleum fuels, resulting in lower than expected deposition and probable reduced corrosion rates.
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Iheaturu, T. C., R. U. Ideozu, S. Abrakasa, and A. E. Jones. "Sequence stratigraphy and tectonic framework of the Gabo Field, Niger Delta, Nigeria." Scientia Africana 21, no. 3 (2023): 19–36. http://dx.doi.org/10.4314/sa.v21i3.2.
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This research examines the sequence stratigraphic and structural framework of the Gabo Field Niger Delta, Nigeria. Materials used in this research include 3D seismic volume in Seg-Y, ditch cuttings and wells logs. The methods applied are standard methods in addition to using the Frazier and Galloway approach for genetic sequences. The tectonic framework was interpreted in terms of deformational, depositional and post-depositional structures. The deformational structures are faults F1 and F2 – which are closely spaced normal faults and F3 is a syn-depositional growth fault. The depositional structures are pinchouts and interbedded sand/shale sequences whereas the postdepositional structures are compaction and smearing or flexure of the shales. The well correlation shows the sequences are cyclic and the facies analysis of T4 – T9 sands are very fine to medium grained, light to dark brown, texturally mature and moderate to well sorted. The facies associations are fluvial distributary channel, tide dominated fluvial channels, abandoned channel or switching and flood plain deposits. While the depositional environments are upper delta plain, lower delta plain and delta front. Sequence stratigraphic analysis explained the observed increase in shale thickness in the intermediate sections and showed sediment deposition occurred in three (3) systems tracts- Lowstand Systems Tract (LST), the Transgressive Systems Tract (TST) and Highstand Systems Tract (HST). The sedimentological model showed the environments of deposition had a tidal influence and ranged from fluvial to estuarine. The findings of this research may be applied to similar deltaic basins around the world in planning of oilfield development. In addition it may correlate cyclic successions and predict facies distributions of similar depositional patterns.
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Kar, Nihar Ranjan, Devleena Mani, Bala Subrahanyam Seetha, et al. "Biomarker Evidence of Shifts in Organic Provenance and Depositional Environments of Eocene Carbonaceous Rocks from Petroliferous Barmer Basin, Western Rajasthan, India." Journal Of The Geological Society Of India 101, no. 1 (2025): 112–22. https://doi.org/10.17491/jgsi/2024/174065.
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ABSTRACT The Barmer Basin of Rajasthan in western India is a proven sedimentary basin with significant oils and natural gas reserves. The basin also possesses lignites and interbedded shales, which are organically-rich and lie close to early mature thermal window. Previous studies have demonstrated that these carbonaceous rocks can be converted into into various hydrocarbon products. We characterise the sedimentary biomarkers and stable carbon isotopes from the Eocene carbonaceous rocks of the Giral lignite mine in the Barmer basin to understand their organic provenance and the depositional environments. Different biomarker ratios of alkanes, hopanes and steranes viz., CPI, OEP, Paq, TAR, TMD, Pr/Ph, LMWH/HMWH, Pr/n-C17, Ph/n-C18, Ts/Tm and C31 22S/ (22S+22R) along withn-alkane chromatogram, several bivariate plots, sterane ternary diagram and stable carbon isotope characterize the depositional environment and different types of organic matter (OM) inputs. The Giral lignites deposited in a terrestrial environment fluctuated from oxic to dysoxic with bimodal OM input. The shales were deposited in a marine or lacustrine environment with predominantly aquatic OM input, in contrast to lignites. Shaly lignites show an intermediate depositional environment between lignite and shales and pseudo-bimodal OM input. Sea-level fluctuations led to deposition of various lithotypes under changing depositional environments. Shales and shaly lignites, unlike lignites, exhibit better preservation conditions due to a predominantly anoxic sulphidic environment. The reduced carbon content of shales may be due to a quicker subsidence rate of the basin than peat formation during shale deposition.
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Kar, Nihar Ranjan, Devleena Mani, Bala Subrahanyam Seetha, et al. "Biomarker Evidence of Shifts in Organic Provenance and Depositional Environments of Eocene Carbonaceous Rocks from Petroliferous Barmer Basin, Western Rajasthan, India." Journal Of The Geological Society Of India 101, no. 1 (2025): 112–22. https://doi.org/10.17491/jgsi/2025/174065.
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ABSTRACT The Barmer Basin of Rajasthan in western India is a proven sedimentary basin with significant oils and natural gas reserves. The basin also possesses lignites and interbedded shales, which are organically-rich and lie close to early mature thermal window. Previous studies have demonstrated that these carbonaceous rocks can be converted into into various hydrocarbon products. We characterise the sedimentary biomarkers and stable carbon isotopes from the Eocene carbonaceous rocks of the Giral lignite mine in the Barmer basin to understand their organic provenance and the depositional environments. Different biomarker ratios of alkanes, hopanes and steranes viz., CPI, OEP, Paq, TAR, TMD, Pr/Ph, LMWH/HMWH, Pr/n-C17, Ph/n-C18, Ts/Tm and C31 22S/ (22S+22R) along withn-alkane chromatogram, several bivariate plots, sterane ternary diagram and stable carbon isotope characterize the depositional environment and different types of organic matter (OM) inputs. The Giral lignites deposited in a terrestrial environment fluctuated from oxic to dysoxic with bimodal OM input. The shales were deposited in a marine or lacustrine environment with predominantly aquatic OM input, in contrast to lignites. Shaly lignites show an intermediate depositional environment between lignite and shales and pseudo-bimodal OM input. Sea-level fluctuations led to deposition of various lithotypes under changing depositional environments. Shales and shaly lignites, unlike lignites, exhibit better preservation conditions due to a predominantly anoxic sulphidic environment. The reduced carbon content of shales may be due to a quicker subsidence rate of the basin than peat formation during shale deposition.
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Ridame, C., J. Dekaezemacker, C. Guieu, S. Bonnet, S. L'Helguen, and F. Malien. "Phytoplanktonic response to contrasted Saharan dust deposition events during mesocosm experiments in LNLC environment." Biogeosciences Discussions 11, no. 1 (2014): 753–96. http://dx.doi.org/10.5194/bgd-11-753-2014.
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Abstract. The response of the phytoplanktonic community (primary production and algal biomass) to contrasted Saharan dust events (wet and dry deposition) was studied in the framework of the DUNE "a DUst experiment in a low-Nutrient, low-chlorophyll Ecosystem" project. We simulated realistic dust deposition events (10 g m−2) into large mesocosms (52 m3). Three distinct experimental dust additions were conducted in June 2008 (DUNE-1-P: simulation of a wet deposition, DUNE-1-Q: simulation of a dry deposition) and 2010 (DUNE-2-R1, -R2: simulation of 2 successive wet depositions) in the northwestern oligotrophic Mediterranean Sea. No changes in primary production (PP) and chlorophyll a concentration (Chl a) were observed after a dry deposition event while a wet deposition event resulted in a rapid (24 h after dust additions), strong (up 2.4 fold) and long (at least a week duration) increase in PP and Chl a. We show that in addition to being a source of dissolved inorganic phosphorus (DIP), simulated wet deposition events were also a significant source of NO3− (net increases up to +9.8 μM NO3− at 0.1 m depth) to the nutrient depleted surface waters due to cloud processes and mixing with anthropogenic species such as HNO3. The dry deposition event was shown to be a negligible source of NO3−. By transiently increasing DIP and NO3− concentrations in P-N starved surface waters, wet deposition of Saharan dust was able to relieve the potential N or NP co-limitation of the phytoplanktonic activity. Due to the higher input of NO3− relative to DIP, a wet deposition event resulted in a strong increase in the NO3−/DIP ratio from initially < 6 to over 150 at the end of the DUNE-2-R1 experiment suggesting a switch from an initial N or NP co-limitation towards a severe P limitation. We also show that the contribution of new production to PP increased after wet dust deposition events from initially 15% to 60–70% 24 h after seeding, indicating a switch from a regenerated-production based system to a new-production based system. DUNE experiments show that wet and dry dust deposition events induce contrasted responses of the phytoplanktonic community due to differences in the atmospheric supply of bioavailable new nutrients. Our results from original mesocosm experiments demonstrate that atmospheric dust wet deposition greatly influences primary productivity and algal biomass in LNLC environments, changes nutrient stocks and alters the NO3−/DIP ratio leading to a switch in the nutrient limitation of the phytoplanktonic activity.
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Wang, Wei, Lixue Guan, Zhang Wen, Xin Ma, Jiangping Fang, and Xuejun Liu. "Atmospheric Nitrogen Deposition to a Southeast Tibetan Forest Ecosystem." Atmosphere 11, no. 12 (2020): 1331. http://dx.doi.org/10.3390/atmos11121331.
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With atmospheric reactive nitrogen (Nr) emissions increasing globally, research into Nr deposition has attracted increasing attention, especially in remote environments. These ecosystems are very sensitive to global change, especially enhanced Nr deposition. Forest environments, in particular, are highlighted because of their important ecological function. We quantified atmospheric Nr concentrations and deposition over four years of continuous monitoring in a southeast Tibetan boreal forest ecosystem, an ecosystem in which forest biomass and carbon density are high around the world. Average annual bulk Nr deposition was 3.00 kg N ha−1 y−1, with those of reduced and oxidized species estimated at 1.60 and 1.40 kg N ha−1 y−1, respectively. Bulk deposition of both NH4+ and NO3− were controlled by precipitation amount: both Nr deposition and precipitation were highest in summer and lowest in winter. Dry deposition of NH3 and NO2 were 1.18 and 0.05 kg N ha−1 y−1, respectively. Atmospheric NH3 concentrations were in the range 1.15–3.53 mg N L−1, highest in summer and lowest in winter. In contrast, no clear trend in seasonal NO2 concentrations was observed. Monthly NO2 concentrations were 0.79–1.13 mg N L−1. Total Nr deposition (bulk plus dry) was 4.23 (3.00 + 1.23) kg N ha−1 y−1 in the forest. Reduced nitrogen was the dominant species. In conclusion, Nr deposition was in the range at which forest net productivity and carbon sequestration are sensitive to any variation in nitrogen input, so quantification of Nr deposition should continue and with greater detail.
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Amer, Zainab. "Facies Analysis and Depositional Stages of The Albian-Aptian Succession in Balad Oil Field, Central Iraq." Iraqi Geological Journal 54, no. 1B (2021): 43–56. http://dx.doi.org/10.46717/igj.54.1b.4ms-2021-02-22.
Full textAbstract:
Carbonate-clastic succession which includes the Shu'aiba, Nahr Umr and Mauddud formations are representing a part of the Barremian-Aptian Sequence (Wasi'a Group). The present study includes three boreholes (Ba-1, 4 and 8) within the Balad Oil Field. The study area is located in central Iraq. This field represents a subsurface anticline with a northwest to southeast direction axis within the Mesopotamian Zone. Eight types of microfacies were recognized in the succession of the Mauddud and Shu’aiba formations. These microfacies represent shallow open marine, restricted and semi-restricted, reef - back reef, deep open marine and basinal depositional environments. While Nahr Umr Formation includes two successions, the first is the upper unit which is characterized by shale dominated rocks and the second is the lower unit which is characterized by sand-dominated rocks. Four major lithofacies were recognized in these two successions, they represent four depositional environments which are distributary channel, bay fill, delta plain and prodelta. The Albian-Aptian sequence was deposited during three cycles overlying the regional unconformity below the Shu’aiba Formation, the Zubair Formation, and ended with local unconformity with the Ahmadi Formation. The first stage is represented by deposition of Shu’aiba Formation during the sea-level rise after regression stage during the Zubair deposition which deposition in delta association facies. The second stage was showed a regressed of deposit the delta system above the shallow open marine of the Shu’aiba Formation, where the succession became characterized by mud-dominated rock with fissile and organic material. The third depositional stage is represented by the continuation of sea-level rise. This transgression leads to the building of carbonate ramp of the Mauddud Formation above the deltaic system of Nahr Umr Formation with a conformable surface. The Mauddud depositional stage was represented by two cycles of transgression succession, where appeared deepening upward in both cycles. The unconformity between these formations have been determined by observing the glauconite mineral and detected by log response in depth 2880m in well Ba-1.
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Riggs, N. R., T. B. Sanchez, and S. J. Reynolds. "Evolution of the early Mesozoic Cordilleran arc: The detrital zircon record of back-arc basin deposits, Triassic Buckskin Formation, western Arizona and southeastern California, USA." Geosphere 16, no. 4 (2020): 1042–57. http://dx.doi.org/10.1130/ges02193.1.
Full textAbstract:
Abstract A shift in the depositional systems and tectonic regime along the western margin of Laurentia marked the end of the Paleozoic Era. The record of this transition and the inception and tectonic development of the Permo-Triassic Cordilleran magmatic arc is preserved in plutonic rocks in southwestern North America, in successions in the distal back-arc region on the Colorado Plateau, and in the more proximal back-arc region in the rocks of the Buckskin Formation of southeastern California and west-central Arizona (southwestern North America). The Buckskin Formation is correlated to the Lower–Middle Triassic Moenkopi and Upper Triassic Chinle Formations of the Colorado Plateau based on stratigraphic facies and position and new detrital zircon data. Calcareous, fine- to medium-grained and locally gypsiferous quartzites (quartz siltstone) of the lower and quartzite members of the Buckskin Formation were deposited in a marginal-marine environment between ca. 250 and 245 Ma, based on detrital zircon U-Pb data analysis, matching a detrital-zircon maximum depositional age of 250 Ma from the Holbrook Member of the Moenkopi Formation. An unconformity that separates the quartzite and phyllite members is inferred to be the Tr-3 unconformity that is documented across the Colorado Plateau, and marks a transition in depositional environments. Rocks of the phyllite and upper members were deposited in wholly continental depositional environments beginning at ca. 220 Ma. Lenticular bodies of pebble to cobble (meta) conglomerate and medium- to coarse-grained phyllite (subfeldspathic or quartz wacke) in the phyllite member indicate deposition in fluvial systems, whereas the fine- to medium-grained beds of quartzite (quartz arenite) in the upper member indicate deposition in fluvial and shallow-lacustrine environments. The lower and phyllite members show very strong age and Th/U overlap with grains derived from Cordilleran arc plutons. A normalized-distribution plot of Triassic ages across southwestern North America shows peak magmatism at ca. 260–250 Ma and 230–210 Ma, with relatively less activity at ca. 240 Ma, when a land bridge between the arc and the continent was established. Ages and facies of the Buckskin Formation provide insight into the tectono-magmatic evolution of early Mesozoic southwestern North America. During deposition of the lower and quartzite members, the Cordilleran arc was offshore and likely dominantly marine. Sedimentation patterns were most strongly influenced by the Sonoma orogeny in northern Nevada and Utah (USA). The Tr-3 unconformity corresponds to both a lull in magmatism and the “shoaling” of the arc. The phyllite and upper members were deposited in a sedimentary system that was still influenced by a strong contribution of detritus from headwaters far to the southeast, but more locally by a developing arc that had a far stronger effect on sedimentation than the initial phases of magmatism during deposition of the basal members.