Journal articles on the topic 'Sedimentation and deposition – Champlain, Lake'
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1
Normandeau, Alexandre, Patrick Lajeunesse, Annie-Pier Trottier, Antoine G. Poiré, and Reinhard Pienitz. "Sedimentation in isolated glaciomarine embayments during glacio-isostatically induced relative sea level fall (northern Champlain Sea basin)." Canadian Journal of Earth Sciences 54, no. 10 (October 2017): 1049–62. http://dx.doi.org/10.1139/cjes-2017-0002.
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The nature of glaciomarine sediments deposited during ice margin retreat can vary according to physiographic setting and relative sea level fluctuations. To understand the effects of these two parameters on sedimentation, we analyzed the sediment records of four lakes located within former isolated glaciomarine embayments of the northern Champlain Sea basin. These lakes were initially inundated by marine water of the Champlain Sea, following deglaciation, and have subsequently experienced basin isolation owing to glacio-isostatic rebound. Three of these lakes reveal a common litho- and acoustic stratigraphic succession, characterized by an IRD-free glaciomarine to marine facies consisting of homogeneous to faintly laminated clayey silts grading into well-laminated silts with rapidly deposited layers. These two units recorded the transitional environment from glaciomarine sedimentation below multiyear shorefast ice to increased terrestrial runoff and rapid glacio-isostatic rebound once the ice margin retreated inland. During ice margin retreat, relative sea level fell concomitantly resulting in the deposition of coarser sediments in marine embayments. Upon the complete retreat of the ice margin, the supply of terrestrial sediments diminished and lake isolation, driven by relative sea level fall, led to higher biogenic content and increased bioturbation. This study provides a framework for sedimentation in isolated glaciomarine embayments which differs from deep-water sedimentation owing to the presence of shorefast sea-ice and their protected location from major ice-stream outlets.
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Hersi, Osman Salad, and George R. Dix. "Hog's Back Formation: a new (Middle Ordovician) stratigraphic unit, Ottawa Embayment, eastern Ontario, Canada." Canadian Journal of Earth Sciences 34, no. 5 (May 1, 1997): 588–97. http://dx.doi.org/10.1139/e17-047.
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The Hog's Back Formation, exposed in Ottawa, Ontario, is a new stratigraphic unit that disconformably overlies the Rockcliffe Formation and underlies, with apparent conformity, the Pamelia Formation of the Ottawa Group. The Hog's Back Formation is 14.3 m thick at its type section (Prince of Wales Falls, Ottawa) and thickens eastward to 27 m in Russell County, about 40 km southeast of Ottawa. It consists of lower, dark green shales with thin lime-mudstone and sandstone interbeds, and upper thin to thick beds of fine crystalline greenish grey sandy and calcareous dolostones with thin to medium (10–30 cm) pinkish grey, bioclastic packstone and grainstone interbeds. The latter thicken eastward and correlate with the "St. Martin calcarenites" of the Beaconsfield Member, Laval Formation, in the Montréal area. Together, these beds correlate with the Valcour Formation, Chazy Group, in the Lake Champlain area of New York. Conodonts and macrofossils indicate a Chazyan (Llandeilian) age for the Hog's Back Formation. The lower sandstone–shale–carbonate assemblage of the formation indicates sedimentation in peritidal environments, and documents initial regional flooding of nearshore sandy facies of the Rockcliffe Formation. The overlying carbonate facies represent sabkha environments punctuated by storm deposition. The gross shallowing-upward succession of the formation was terminated by renewed flooding associated with another regional transgressive event heralding deposition of the Ottawa Group.
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Naldrett, Dana L. "Sedimentology, Stratigraphy and Micropaleontology of Pre- and Early-Champlain Sea Fine-Grained Facies from the Foster Sand Pit, Ottawa, Ontario." Géographie physique et Quaternaire 42, no. 2 (December 18, 2007): 181–89. http://dx.doi.org/10.7202/032724ar.
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ABSTRACT The Foster sand pit exposes pre- to late-Champlain Sea sediments containing 4 litho/biofacies. These are, from oldest to youngest: Faciès 1- cross-stratified sand and diamicton deposited as late-glacial, ice-proximal subaqueous outwash. Faciès 2- laminated silt and clay rhythmites with a sparse Candona cf. C. subtriangulata ostracode fauna deposited in a deep, proglacial lake preceding the Champlain Sea, Fades 3- massive to rarely laminated silty clay with dominant foraminifera Elphidium bartletti, Protelphidium orbiculare and Cassidulina crassa represents the first glaciomarine deposition in Champlain Sea water 30-100 m deep with a paleosalinity of 22-33 %o. Faciès 4- mixed bedding of sand and mud, with a microfossil assemblage dominated by the Elphidium/Protelphidium complex representing an intertidal offlap sequence. Water depths during deposition of Faciès 4 dropped to 10-30 m. and paleosalinity dropped to 18-28 %o.. This study recognizes a pre-Champlain Sea proglacial lake, assigns subaqueous outwash deposits to an earlier time than previously believed and documents changes in bottom water characteristics of the early Champlain Sea based on sedimentary and microfossil evidence.
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Jonas, Jory L., Randall M. Claramunt, John D. Fitzsimons, J. Ellen Marsden, and Brian J. Ellrott. "Estimates of egg deposition and effects of lake trout (Salvelinus namaycush) egg predators in three regions of the Great Lakes." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 10 (October 1, 2005): 2254–64. http://dx.doi.org/10.1139/f05-141.
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Excessive mortality from spawning through the first year of life is likely responsible for recruitment failures in many lake trout (Salvelinus namaycush) populations. We evaluated relationships between interstitial predator species and lake trout egg deposition in three regions of the Great Lakes. The introduced crayfish Orconectes rusticus dominated the nearshore zone in northern Lake Michigan, whereas other sites in Lake Michigan and Parry Sound were dominated by native Orconectes propinquus. In Lake Champlain, sculpin (Cottus spp.) were the most common interstitial predator, yet densities were comparable with those in Lake Michigan. Predator densities in Lake Michigan (mean ± standard error = 15.5 ± 0.4 predators·m2) were twice those in Lake Champlain or Parry Sound (6 ± 1 predators·m2). Densities of eggs were higher in Lake Champlain (2994.1 ± 398.3 eggs·m2) and Parry Sound (454.7 ± 36.3) than in Lake Michigan (7.5 ± 1.3; Kruskal-Wallis, P ≤ 0.05). Ratios of eggs to predator provide simple measures of the effectiveness of lake trout rehabilitation efforts. The average ratio calculated from 10 successful spawning locations is 190 eggs·predator1·m2. Ratios may help establish target egg densities for restoration efforts and the concentration of spawning adults required to allow survival to the fry stage.
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Rayburn, John A., Thomas M. Cronin, David A. Franzi, Peter L. K. Knuepfer, and Debra A. Willard. "Timing and duration of North American glacial lake discharges and the Younger Dryas climate reversal." Quaternary Research 75, no. 3 (May 2011): 541–51. http://dx.doi.org/10.1016/j.yqres.2011.02.004.
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AbstractRadiocarbon-dated sediment cores from the Champlain Valley (northeastern USA) contain stratigraphic and micropaleontologic evidence for multiple, high-magnitude, freshwater discharges from North American proglacial lakes to the North Atlantic. Of particular interest are two large, closely spaced outflows that entered the North Atlantic Ocean via the St. Lawrence estuary about 13,200–12,900 cal yr BP, near the beginning of the Younger Dryas cold event. We estimate from varve chronology, sedimentation rates and proglacial lake volumes that the duration of the first outflow was less than 1 yr and its discharge was approximately 0.1 Sv (1 Sverdrup = 106 m3 s−1). The second outflow lasted about a century with a sustained discharge sufficient to keep the Champlain Sea relatively fresh for its duration. According to climate models, both outflows may have had sufficient discharge, duration and timing to affect meridional ocean circulation and climate. In this report we compare the proglacial lake discharge record in the Champlain and St. Lawrence valleys to paleoclimate records from Greenland Ice cores and Cariaco Basin and discuss the two-step nature of the inception of the Younger Dryas.
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Liverman, David G. E. "Sedimentation in ice-dammed Hazard Lake, Yukon." Canadian Journal of Earth Sciences 24, no. 9 (September 1, 1987): 1797–806. http://dx.doi.org/10.1139/e87-171.
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"Hazard Lake," located in Kluane National Park, the Yukon, is an ice-dammed lake formed in 1966 by the surge of the Steele Glacier. Since 1975 it has drained annually by means of a subglacial tunnel. During July 1979, observations were made of lake processes before drainage and of sections described in the lake bottom after drainage. Three facies associations are believed to represent prelake, stable lake, and annual draining phases. Gravel commonly found at the base of sections represents deposition in a braided fluvial system prior to 1966. Lake sediments deposited between 1966 and 1975 are dominantly graded laminated silt deposited by turbid underflow from the major inflow stream. Lamination is probably caused by diurnal underflow events or daily variation in strength of underflow. No "winter" clay component of varved sediments is observed. During drainage a regressive sequence is deposited as the lake level drops, with sand-dominated sediments overlapping laminated silt where the main inflow stream enters the lake. This is followed by local fluvial deposition along the course of the reestablished stream. During filling a transgressive sequence is deposited as the lake level rises. Sand-dominated deltaic sedimentation is followed by deposition from underflow, resulting in laminated and massive silt and clay. These fine-grained facies separate sand facies and demark individual filling events but are easily eroded. Thus it is not possible to identify the effects of each individual drainage–filling cycle in the sediments. After drainage the lake remains empty until the next melt season, during which time a braided stream is established in the lake basin, depositing sands and gravels and eroding lake sediments.
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Kusumgar, Sheela, D. P. Agrawal, and Prabhakar Sharma. "Radiocarbon Chronology and Magnetic Susceptibility Variation in Kumaon Lake Sediments." Radiocarbon 31, no. 03 (1989): 957–64. http://dx.doi.org/10.1017/s0033822200012583.
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This study was carried out to determine time controls of erosion and sedimentation in the catchment area and lakes of the Naini Tal district in the Kumaon Himalayas. We present here our preliminary data from five lakes, Beon Tal, Garud Tal, Sukha Tal, Bhim Tal and Kamal Tal (Naukuchia Tal). A number of 14C dates are now available to estimate the sedimentation rate of the five lakes and magnetic susceptibility (xL; xfd) variation to determine the signature of sediment source. High xfd values indicate a higher proportion of soil component generally characterized by a slower rate of deposition, and low xfd values with a higher rate of sedimentation indicate rock-debris-derived sediment. A 14C chronology enables us to estimate the mean sedimentation rate whereas rock magnetic properties help us to characterize the type of source responsible for sedimentation.
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Leonard, Eric M. "Varve Studies at Hector Lake, Alberta, Canada, and the Relationship Between Glacial Activity and Sedimentation." Quaternary Research 25, no. 2 (March 1986): 199–214. http://dx.doi.org/10.1016/0033-5894(86)90057-8.
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Glacial lake sedimentary records from Hector Lake in Banff National Park, Alberta, are examined with the aim of clarifying the relationship between glacial activity and outwash sedimentation. Rhythmic couplets in lake bottom sediments provide a method for accurate documentation and dating of recent sedimentation chronology, as analysis of 137Cs content indicates that the couplets are of annual periodicity (i.e., varves). A comparison of sedimentation rate records with recent regional glacial history indicates that high sedimentation rates of one to a few decades duration occur either during and immediately following periods of moraine deposition (ie, maximum ice stands) or during periods of rapid ice recession. Comparison of sedimentary records with somewhat longer term glacial and vegetation records indicates that sedimentation rate variations of several centuries duration closely parallel changes in upvalley ice extent. Over this time scale, high sedimentation rates occur during periods of relatively increased ice extent, low rates during periods of reduced ice extent. Within this general pattern, however, sedimentation rates may remain very high for nearly a century following maximum ice stands, due to the exposure of unstable glaciogenic deposits to fluvial reworking during ice recession.
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Cuddington, K., and P. R. Leavitt. "An individual-based model of pigment flux in lakes: implications for organic biogeochemistry and paleoecology." Canadian Journal of Fisheries and Aquatic Sciences 56, no. 10 (October 1, 1999): 1964–77. http://dx.doi.org/10.1139/f99-108.
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Vertical fluxes of pigments are used in limnology to monitor phytoplankton abundance, herbivore grazing, ecosystem efficiency, and historical changes in production. However, significant pigment degradation can occur during algal sedimentation. We used an individual-based model of pigment flux to quantify the relative importance of production and degradation as controls of pigment sedimentation. Pigment deposition increased with production, sinking rate, and phytoplankton depth and declined as lake depth and the depth of oxygen penetration increased. Unexpectedly, pigment sedimentation rate was not sensitive to variation in photooxidation rates, even though bleaching accounted for the second greatest amount of pigment loss. Digestion by zooplankton caused the most pigment degradation, but grazing increased pigment deposition when digestive losses were less than those due to oxidation of pigments in ungrazed cells. The model suggests that algal production may be underestimated in sedimentation studies that do not consider variability in water column depth. Further, comparisons with paleoecological analyses suggest that some inferred increases in production during lake ontogeny may arise from changes in regulation of pigment fluxes rather than from increased algal production.
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Burke, J., M. Hoyer, G. Keeler, and T. Scherbatskoy. "Wet deposition of mercury and ambient mercury concentrations at a site in the Lake Champlain basin." Water, Air, & Soil Pollution 80, no. 1-4 (February 1995): 353–62. http://dx.doi.org/10.1007/bf01189685.
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Dobson, Evan P., and Gerald L. Mackie. "Increased deposition of organic matter, polychlorinated biphenyls, and cadmium by zebra mussels (Dreissena polymorpha) in western Lake Erie." Canadian Journal of Fisheries and Aquatic Sciences 55, no. 5 (May 1, 1998): 1131–39. http://dx.doi.org/10.1139/f97-321.
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Biodeposition of organic matter, polychlorinated biphenyls (PCBs), and cadmium (Cd) by zebra mussels (Dreissena polymorpha) was investigated at five stations in the western basin of Lake Erie during the summer of 1992. Biodeposition rates at the five stations were determined by using sediment traps and converted to per unit area values to facilitate comparisons with natural sedimentation rates. Biodeposition of suspended material by zebra mussels was up to 8 times greater than sedimentation in the traps. Concentrations of organic matter, PCBs, and Cd were determined for the biodeposits and the sedimented material. There were no significant differences in concentration of organic matter, PCBs, or Cd between the two types of material. Biodeposition rates per unit area of organic matter, PCBs, and Cd were 8-10 times greater than corresponding values for natural sedimentation; therefore, the natural sedimentation processes of these factors appear to be greatly accelerated in the presence of zebra mussels. Results support the possibility that zebra mussels are altering contaminant movement in western Lake Erie, as well as clarifying the water column by removing suspended material.
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Lewis, C. F. M., and T. W. Anderson. "A younger glacial Lake Iroquois in the Lake Ontario basin, Ontario and New York: re-examination of pollen stratigraphy and radiocarbon dating." Canadian Journal of Earth Sciences 57, no. 4 (April 2020): 453–63. http://dx.doi.org/10.1139/cjes-2019-0076.
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Revision of palynochronologic and radiocarbon age estimates for the termination of glacial Lake Iroquois, mainly based on a currently accepted younger determination of the key Picea–Pinus pollen transition, shows agreement with recently established constraints for this late glacial event in the Lake Ontario basin at 13 000 cal years BP. The date of emergence or isolation of small lake basins reflects the termination of inundation by glacial lake waters. The increasing upward presence of plant detritus and the onset of organic sedimentation marks the isolation level in the sediments of a small lake basin. The upward relative decline and cessation of pollen from trees such as Pinus, Quercus, and other thermophilous hardwoods that were wind transported long distances from southern areas also mark the isolation of inundated small lake basins by the declining water level of Lake Iroquois as local vegetation grew and local pollen overwhelmed long-distance-transported pollen. Re-examination of data in small lake basins north of Lake Ontario using the above criteria shows that the age range for the termination of Lake Iroquois derived from these data overlaps other age constraints. These constraints are based on a varve-estimated duration of post-Iroquois phases before incursion of the Champlain Sea, a newly discovered late ice advance into northern New York State, and the age of a mastodon at Cohoes, New York. The new age (13 000 cal years BP) for Lake Iroquois termination is significantly younger than the previous estimate of 11 800 14C (13 600 cal) years BP.
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Begy, Robert-Csaba, Codrin F. Savin, Szabolcs Kelemen, Daniel Veres, Octavian-Liviu Muntean, Cristian V. Malos, and Tibor Kovacs. "Investigation of the effect of anthropogenic land use on the Pănăzii Lake (Romania) catchment area using Cs-137 and Pb-210 radionuclides." PLOS ONE 16, no. 6 (June 17, 2021): e0251603. http://dx.doi.org/10.1371/journal.pone.0251603.
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The problem of soil degradation has accentuated over recent decades. Aspects related to soil erosion and its relation to changes in land use as well as anthropogenic influence constitute a topic of great interest. The current study is focused on a soil erosion assessment in relation to land use activities in the Pănăzii Lake catchment area. Fallout radionuclides were used to provide information on soil erosion as well as redistribution rates and patterns. Variations in the sedimentation rate of the lake were also investigated as these reflect periods in which massive erosion events occurred in the lake catchment area. The novelty of this study is the construction of a timescale with regard to the soil erosion events to better understand the relationship between soil erosion and land use activities. In this study, 10 soil profiles and one sediment core from the lake were taken. Soil parameters were determined for each sample. The activities of 210Pb, 137Cs and 226Ra were measured by gamma spectroscopy. For low 210Pb activities, measurements via 210Po using an alpha spectrometer were performed. Soil erosion rates were determined by the 137Cs method and the sedimentation rate calculated by the Constant Rate of Supply (CRS) model. A soil erosion rate of 13.5 t·ha-1·yr-1 was obtained. Three distinct periods could be observed in the evolution of the sedimentation rate. For the first period, between 1880 and 1958, the average deposition rate was 9.2 tons/year, followed by a high deposition period (1960–1991) of 29.6 tons/year and a third period, consisting of the last 30 years, during which the sedimentation rate was 15.7 tons/year. These sedimentation rates fluctuated depending on the main land use activity, which can also be seen in the soil erosion rates that had almost doubled by the time agricultural activities were performed in the area.
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Podsetchine, V., and T. Huttula. "Modelling Sedimentation and Resuspension in Lakes." Water Quality Research Journal 29, no. 2-3 (May 1, 1994): 309–42. http://dx.doi.org/10.2166/wqrj.1994.020.
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Abstract A 2-D vertical flow and suspended matter transport model and a 3-D transport model are described. Existing parameterizations of resuspension and deposition of sediments on the bottom are discussed. Models were applied for calculation of unsteady sediment transport in Lake Karhijärvi, Finland, for a five-day period with high winds and heavy rain in autumn 1992. A parabolic distribution of vertical eddy diffusivity was found to be applicable. Erosion was approximated with cubic dependence on bed shear stress. The 3-D model showed that the observed turbidity peak in the middle of the lake was caused by suspended matter transport through the River Susikoski. Sediment resuspension was found to be limited in the areas with depth less than 1 m. The 2-D vertical model was useful for determination of erosion under certain weather conditions, but for detailed analysis in space and time a 3-D model with high resolution is required.
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Parent, Michel, and Serge Occhietti. "Late Wisconsinan deglaciation and glacial lake development in the Appalachians of southeastern Québec." Géographie physique et Quaternaire 53, no. 1 (October 2, 2002): 117–35. http://dx.doi.org/10.7202/004859ar.
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Abstract Late Wisconsinan deglaciation in southeastern Québec was preceded by a northward ice-flow reversal that was recorded in the northeastern part of the region. The reversal event was generated by flow convergence toward the St. Lawrence Ice Stream, a northeastward-flowing ice stream which formed in the St. Lawrence estuary prior to 13 000 years BP and lasted until at least 12 400 years BP. In the Bois-Francs uplands, the flow reversal event led to the formation of a semi-detached ice mass that underwent widespread stagnation and downwasting. In the southwestern region, northward retreat of the margin of the Laurentide Ice Sheet was marked by the formation of a series of discontinuous recessional moraines and by the development of ice-dammed lakes in the main valleys. The level of these lakes fell as progressively lower outlets became ice-free. The main episodes are (1) the Sherbrooke Phase of Glacial Lake Memphremagog, (2) an unnamed transitional lake and (3) Glacial Lake Candona, a large lake which had expanded northeastward from the deglaciated regions of the Upper St. Lawrence (Lake Iroquois) and Ottawa valleys to the Lake Champlain (Glacial Lake Vermont) basin. As recorded by the Danville Varves, Lake Candona lasted about 100 years following deposition of the Ulverton-Tingwick Moraine. Subsequent ice retreat along the Appalachian piedmont led to final drainage of Lake Candona and allowed Champlain Sea waters to invade much of these glaciolacustrine terrains about 12 000 years BP. On the basis of the Danville Varves record, a regional rate of ice retreat of about 200 m·a -1 is inferred. The age of the earliest moraine, the Frontier Moraine, is thus about 12 550 years BP, while the ages of the subsequent Dixville, Cherry River-East-Angus, Mont Ham and Ulverton-Tingwick moraines are estimated at 12 500, 12 325, 12 200 et 12 100 years BP, respectively.
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Henderson, Penny J. "Sedimentation in an esker system influenced by bedrock topography near Kingston, Ontario." Canadian Journal of Earth Sciences 25, no. 7 (July 1, 1988): 987–99. http://dx.doi.org/10.1139/e88-098.
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Late Wisconsinan sand and gravel deposits on the Frontenac Arch, Ontario, record a major meltwater drainage system developed subglacially and subaqueously in one or more glacial lake phases of the Lake Ontario basin during retreat of the Laurentide Ice Sheet. Factors influencing channel location, morphology, and sediment deposition are ice flow direction and the Precambrian bedrock topography, in turn dependent upon bedrock structure and composition. Meltwater drainage across the Frontenac Arch is localized within a broad depression oriented approximately parallel to glacial flow. Sediment deposition within the regional depression follows ice-flow direction despite irregular bedrock relief, indicating formation of the meltwater system and associated sediments in three stages: (i) establishment of a continuous meltwater system subglacially under high hydrostatic pressure with minor erosion of underlying Precambrian bedrock; (ii) deposition of poorly sorted, coarse-grained sediment in cavities or channels associated with irregular bedrock topography; and (iii) deposition of several coalescing subaqueous outwash fans at the ice margin as the glacier receded from the area. The discontinuous nature of the deposits and the association of proximal to distal outwash fan facies within a deposit suggest that esker sedimentation occurred during periodic stabilization of the ice front during deglaciation.
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Khrushcheva, Maria O., Ekaterina M. Dutova, Platon A. Tishin, Alexander L. Arkhipov, Alexei N. Nikitenkov, and Alexei I. Chernyshov. "Taloe—Sedimentation in an Intermittent Lake (Russian Federation, Republic of Khakassia)." Minerals 11, no. 5 (May 14, 2021): 522. http://dx.doi.org/10.3390/min11050522.
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This paper examines the mineral and geochemical features of lake sediments and waters in intermittent Lake Taloe, located in a semiarid climate. Minerals that belong to groups of oxides, sulfides, aluminosilicates, carbonates, sulfates, and halides are identified through the use of precision methods. The resulting mineral species are divided by genetic features into two associations: terrigenous and hydrogenic. The terrigenous association includes water-insoluble minerals, while the hydrogenic association combines typical hydrogenic minerals. The regularities of the accumulation and distribution of minerals along the lake laterally and to a depth of up to one meter are also examined. The order of deposition of hydrogenous association minerals from sulfate-chloride lake waters was established. The obtained results are confirmed and supplemented by physicochemical calculations, which show the equilibrium of lake waters with hydroxides, oxides, aluminosilicates, carbonates, and sulfates. It has been established that the formation of minerals mainly occurs through evaporative concentration in conjunction with bedrock weathering.
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Sharpe, David R., and W. R. Cowan. "Moraine formation in northwestern Ontario: product of subglacial fluvial and glaciolacustrine sedimentation." Canadian Journal of Earth Sciences 27, no. 11 (November 1, 1990): 1478–86. http://dx.doi.org/10.1139/e90-157.
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Long, arcuate, stratified end moraines in northwestern Ontario may represent major and rapid sedimentation events in glacial Lake Agassiz. Rapid lowering of the lake or lift of a marginal ice dam may have triggered widespread outbursts of subglacial meltwater which deposited these end moraines as coalesced or broad subaqueous lacustrine fans. Moraine cores are of undeformed gravel, sand, and silty sand that fine upward. Coarse beds are massive to weakly stratified. Large-scale cross-stratification may be present. Sandy rhythmic beds are laterally transitional to silt–clay rhythmites (varves). Similar facies occur in adjoining eskers.Moraine sediments have the expected characteristics of rapid deposition on subaqueous fans and, therefore, may not represent either prolonged sedimentation or stable ice margins. Rather, they may reflect rapid sedimentation associated with large discharges that induced transient instability in the drainage network and (or) surging prior to marginal sedimentation. This explanation for moraine formation questions the traditional view that large end moraines represent climatically controlled stillstands.
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Rea, Anne W., Gerald J. Keeler, and Timothy Scherbatskoy. "The deposition of mercury in throughfall and litterfall in the lake champlain watershed: A short-term study." Atmospheric Environment 30, no. 19 (October 1996): 3257–63. http://dx.doi.org/10.1016/1352-2310(96)00087-8.
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Nowaczyk, N. R., E. M. Haltia, D. Ulbricht, V. Wennrich, M. A. Sauerbrey, P. Rosén, H. Vogel, et al. "Chronology of Lake El'gygytgyn sediments." Climate of the Past Discussions 9, no. 3 (June 7, 2013): 3061–102. http://dx.doi.org/10.5194/cpd-9-3061-2013.
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Abstract. A 318 m long sedimentary profile drilled by the International Continental Scientific Drilling Program (ICDP) at Site 5011-1 in Lake El'gygytgyn, Far East Russian Arctic, has been analysed for its sedimentologic response to global climate modes by chrono-stratigraphic methods. The 12 km wide lake is sited in an 18 km large crater that was created by the impact of a meteorite 3.58 Ma ago. Since then sediments have been continuously deposited. For establishing their chronology, major reversals of the Earth's magnetic field provided initial tie points for the age model, confirming that the impact occurred in the earliest Gauss chron. Various stratigraphic parameters, reflecting redox conditions at the lake floor and climatic conditions in the catchment were tuned synchronously to Northern Hemisphere insolation variations and the marine oxygen isotope stack, respectively. Thus, a robust age model comprising more than 600 tie points could be defined. It could be shown that deposition of sediments in Lake El'gygytgyn occurred in concert with global climatic cycles. The upper ~160 m of sediments represent the past 3.3 Ma, equivalent to sedimentation rates of 4 to 5 cm ka−1, whereas the lower 160 m represent just the first 0.3 Ma after the impact, equivalent to sedimentation rates in the order of 45 cm ka−1.
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Russell, Hazen A. J., Robert W. C. Arnott, and David R. Sharpe. "Stratigraphic Architecture and Sediment Facies of the Western Oak Ridges Moraine, Humber River Watershed, Southern Ontario*." Glacial History 58, no. 2-3 (July 18, 2006): 241–67. http://dx.doi.org/10.7202/013141ar.
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Abstract The Oak Ridges Moraine in southern Ontario is a ca. 160 km long east-west trending ridge of sand and gravel situated north of Lake Ontario. Study of the Oak Ridges Moraine in the Humber River watershed was undertaken to assess its role in the groundwater system of the buried Laurentian Valley. The Oak Ridges Moraine is interpreted to have been deposited in three stages. Stage I records rapid deposition from hyperconcentrated flows where tunnel channels discharged into a subglacial lake in the Lake Ontario basin. Low-energy basin sedimentation of Stage II was in a subglacial and ice-contact setting of a highly crevassed ice sheet. Stage III sedimentation is characterized by rapid facies changes associated with esker, subaqueous fan, and basinal sedimentation. Detailed sediment analysis challenges the concept that the Oak Ridges Moraine was deposited principally from seasonal meltwater discharges, climatic modulated ice-marginal fluctuations, or in an interlobate position. Instead it is interpreted to have formed in response to late-glacial ice sheet events associated with subglacial meltwater ponding, episodic and catastrophic subglacial meltwater discharge, and subsequent seasonal meltwater discharge. The moraine probably formed as the glacial-hydraulic system re-equilibrated to the presence of a thinned, grounded ice shelf and a subglacial lake in the Lake Ontario basin.
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Cossu, R., A. L. Forrest, H. A. Roop, G. B. Dunbar, M. J. Vandergoes, R. H. Levy, P. Stumpner, and S. G. Schladow. "Seasonal variability in turbidity currents in Lake Ohau, New Zealand, and their influence on sedimentation." Marine and Freshwater Research 67, no. 11 (2016): 1725. http://dx.doi.org/10.1071/mf15043.
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Layers of sediment that are deposited on the floor of Lake Ohau, New Zealand, offer a means to reconstruct past climate conditions in the Southern Hemisphere at subdecadal and annual resolution. A robust understanding of the modern physical processes that control the influx and dispersal of sediment in the lake is required to reconstruct climate from these sedimentary archives. In this study, water temperature and velocity measurements collected during 2012–13 were analysed to determine the primary physical processes that influence sediment transport in the lake. Sediment input from river inflow occurs throughout the year but exhibits strong seasonal variation. Large inflow events (Q>500m3s–1) that follow strong summer rainstorms trigger high-concentration turbidity currents, which are the main agents for sediment delivery and deposition. During winter, smaller turbidity currents also occur after rain events and contribute to annual sediment accumulation. In addition, large internal waves were observed during the summer and may influence sedimentation. In conclusion, several processes including river inflow, internal waves and convectively driven flows control sediment deposition and accumulation in the Lake Ohau system. We utilise these observations to establish a conceptual model to explain the observed infill stratigraphy in Lake Ohau and guide interpretation of the longer sedimentary record.
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Rice, R. J., and J. A. Donaldson. "Sedimentology of the Archean Doré metasediments, Arliss Lake area, southern Michipicoten greenstone belt, Superior Province." Canadian Journal of Earth Sciences 29, no. 12 (December 1, 1992): 2558–70. http://dx.doi.org/10.1139/e92-203.
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Doré metasediments in the Arliss Lake area of the Michipicoten greenstone belt predominantly represent submarine-fan sedimentation in mid- to outer-fan settings; subaerial deposition was rare, occurring in a sandy braided stream environment and as mud-poor debris flows in a probable fan-delta setting. The Arliss Lake subbasin was likely small, and of an irregular configuration which restricted down-fan sediment distribution, promoting aggradational lobe development; it existed on a convergent plate margin. Felsic pyroclastic volcanism was periodically synchronous with epiclastic sedimentation but only rarely dominated. Paleogeographic development, addressed by comparing juxtaposed thrust-fault-bounded lithological packages of similar facing, suggests that the subbasin experienced several episodes of instability, which caused dramatic changes in relative sea level.
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Gottgens, J. F., and T. L. Crisman. "Quantitative Impacts of Lake-Level Stabilization on Material Transfer between Water and Sediment in Newnans Lake, Florida." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 8 (August 1, 1993): 1610–16. http://dx.doi.org/10.1139/f93-182.
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Spillways at lake outlets reduce water-level fluctuations but may accelerate sedimentation in the lake. In eutrophic Newnans Lake, Florida, a transect of sedimentary profiles, dated with 210Pb and 137Cs by γ-ray spectroscopy, showed threefold increases in accumulation rates of organic matter, total Kjeldahl nitrogen (TKN), and total phosphorus (TP) 1200 m lakeward of a spillway since its construction in 1967. Concentrations of TKN and TP increased 3.5 and 2.4 times, respectively, in sediments deposited since 1967. These increases were progressively less at stations farther from the spillway. Postspillway accumulation of TP was focused toward the dam whereas recent TKN deposition was similar lakewide. Flocculent sediment (> 90% water) accumulated at 1.4 cm/yr. Dams designed to reduce water-level fluctuations may provide short-term benefits for lake access and navigation but in the long-term may accelerate deposition of nutrient-rich detritus, reduce lake volume, cloud the water, alter plant communities, and change lake productivity.
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Lemoine, Rick M., and James T. Teller. "Late Glacial Sedimentation and History of the Lake Nipigon Basin, Ontario." Géographie physique et Quaternaire 49, no. 2 (November 30, 2007): 239–50. http://dx.doi.org/10.7202/033039ar.
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ABSTRACTThe Lake Nipigon basin lies north of the Lake Superior basin and was the hydrological link between glacial Lake Agassiz and the Great Lakes during part of the last deglaciation. A sequence of glaciolacustrine sediments, composed mainly of silt-clay rhythmites and sand, was deposited in the offshore waters of glacial Lake Nipigon by overflow from Lake Agassiz and meltwater from the retreating glacier margin. Sections from six long sediment cores and four lake bluff exposures reveal a sandy (early deglacial) lower section that is overlain by 300 to 850 silt-clay rhythmites (varves). Deposition of these varves, as well as coarser sediment along the western shore, began after 9200 BP, as the glacial margin retreated northward along the continental divide that separated the Nipigon basin from the higher Lake Agassiz basin to the west. The absence of ice rafted clasts in the rhythmites suggests that the ice had retreated from the lake by the time they were deposited. On the basis of their elevation in relation to the lowest raised beach at West Bay, which formed about 9000 BP, most rhythmites probably were deposited between 9000 and 8000 BP. Species of arboreal pollen are present in early postglacial sediments of the Nipigon-Superior lowlands, suggesting that the Lake Nipigon region became colonized by coniferous and deciduous forests soon after déglaciation. The presence of non-arboreal pollen species suggest that these forests were interspersed with open meadows and grasslands, similar to today's floral assemblages. Fossil molluscs recovered from glaciolacustrine sand exposed along the eastern side of the basin suggest that the limnological characteristics of late glacial Lake Nipigon were similar to those of today.
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Ivanova, Varvara V., Alexander A. Shchetnikov, and Steffen Kiel. "Sediment geochemistry of the section Tagay-1 at Olkhon Island (Lake Baikal, Eastern Siberia): a contribution to palaeoenvironmental interpretations." Palaeobiodiversity and Palaeoenvironments 102, no. 4 (December 2022): 921–41. http://dx.doi.org/10.1007/s12549-022-00565-9.
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AbstractThe Miocene Tagay section in the north-western part of Olkhon Island, Lake Baikal, provides a unique window into past life in northern Asia. To aid palaeoenvironmental reconstructions, we carried out whole-rock geochemical analyses of 17 sedimentary layers of this section. The aim of this geochemical approach is to examine the element variations as a response to climate change during formation of the Tagay section deposits with a focus on the hydrological regime of the catchment and in-lake processes. Our results establish that temperature and climate conditions during the formation of sediments of section Tagay-1 were fairly stable, no abrupt climatic changes occurred. The palaeoclimate was temperate, however, it had a cyclic nature: wet and semiarid epochs of different intensity and duration alternated. The basal part of the sediment sequence is dominated by terrigeneous material, mainly by surface runoff, so the sedimentation was fed by erosion products of the weathering crust. During sedimentation of this lower part (layers 17–9), the palaeo-lake level and salinity stayed practically unchanged. The drawdown of the palaeo-lake and increasing salinity started in the higher middle part (layer 8), and reached the minimum water level and maximum salinity in layers 7–6. Sediments of the layers 8–6 accumulated in an arid climate. After deposition of layer 5, the water level began to rise, and during formation of layer 3 it fell again. The highest sedimentation rate was in layers 12–5, these are also the layers with the highest enrichment of biogenic elements (layers 12, 7–5) and where carbonate deposition took place. The observed changes in element behaviour are related to hydrological changes in the catchment (precipitation), lake level status, and evaporation, and are ultimately driven by climate.
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Courtney Mustaphi, Colin J., and Konrad Gajewski. "Holocene sediments from a coastal lake on northern Devon Island, Nunavut, Canada." Canadian Journal of Earth Sciences 50, no. 5 (May 2013): 564–75. http://dx.doi.org/10.1139/cjes-2012-0143.
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Sediment cores from Lake DV09, northern Devon Island, Nunavut, Canada (75°34′34″N, 89°18′55″W), were studied to reconstruct the lake ontogeny through analysis and interpretation of the sediment stratigraphy. The lake was uplifted from marine inundation ∼7600 cal BP. After a millennium of rapid sediment accumulation, which coincided with the Holocene Thermal Maximum in the region, accumulation rates decreased over the past 6000 years as the Arctic became colder. This resulted in the deposition of very fine laminae that were interpreted as varves. The uppermost laminated sediments provided a ∼1600 year history of annual sediment transport and deposition into the lake. During periods of warmer temperatures, such as between 6000 and 7500 cal BP and during the Medieval Climate Anomaly (∼950–1300 CE; CE, Christian Era), hydroclimatic and permafrost slope processes increased sedimentation rates into the basin.
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Naldrett, Dana L. "The Late Glacial-Early Glaciomarine Transition in the Ottawa Valley: Evidence for a Glacial Lake?" Géographie physique et Quaternaire 42, no. 2 (December 18, 2007): 171–79. http://dx.doi.org/10.7202/032723ar.
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ABSTRACT Rhythmites overlying either cross-bedded sand or diamicton are found throughout the Ottawa Valley. Previously thought to be restricted glacial lake sediments, they are now known to be widespread, and represent a large proglacial lake which preceded the Champlain Sea. The rhythmites consist of thin silt and clay laminae which fine upwards and contain slump, flame, shear (ice-contact?) and fluid escape structures. Ice-rafted material is common. The ostracode Candona cf. C. subtriangulata occurs in low numbers and indicates a freshwater body with depth of approximately 200 m. The alternation of silt and clay rhythmite laminae is characteristic of deposition by underflow and overflow currents, respectively. To produce underflows with typical glacial outwash concentrations may require discharge into fresh rather than marine water. This evidence and the widespread occurrence of rhythmites throughout the Ottawa Valley and the Rideau Lakes area suggests a large proglacial lake as the sedimentary basin. The lake is tentatively correlated with the Belleville Phase of Glacial Lake Iroquois and the Ft. Ann Phase of Glacial Lake Vermont. These phases occurred at depths consistent with the requirements for Candona survival. The water body which existed in the Ottawa area is here called Lake Rideau after the type locality where rhythmites were first observed. Generation of such a lake favours the more conventional "window blind" model for déglaciation rather than the calving bay concept.
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Mohammadi, Ali, Razyeh Lak, Georg Schwamborn, Amaneh Kaveh Firouz, Attila Çiner, and Javad Darvishi Khatouni. "Depositional environments and salt-thickness variations in Urmia Lake (NW Iran): Insight from sediment-core studies." Journal of Sedimentary Research 91, no. 3 (March 31, 2021): 296–316. http://dx.doi.org/10.2110/jsr.2020.078.
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ABSTRACT Urmia Lake is a large-scale hypersaline lake that experienced a drastic water-level fall due to natural and anthropogenic forces during the last two decades. Construction of a causeway in the central part of the lake after 1989 has divided the lake into northern and southern parts and caused an extreme change of the lake hydrochemical system. Precipitation of evaporite minerals as crust on the lake floor was caused by the combination of lake level fall and increasing water salinity. However, some parameters controlling rates of salt deposition and dissolution and temporal and spatial variation in salt thickness in Lake Urmia are poorly understood. This study reviews 90 sediment cores from various parts of the lake to put forward a better understanding of the salt depositional system and salt thickness variations in the basin for the last 40 years (1977–2017). Our results indicate that the sedimentary system of Urmia Lake changed rapidly during the last two decades from a permanent hypersaline lake with predominantly fast terrigenous–biochemical sedimentation to a seasonally changing playa sedimentary environment with predominance of evaporite minerals. These changes are responsible for rapid salt deposition that generated a salt-crust with a maximum thickness of 2.95 m overlying Holocene terrigenous sediments. The salt-crust thickness and the water depth have a positive correlation for water depth greater than 1 meter, which means that salt-crust thickness increases where water depth increases. While the thickness of shallow deposits are affected by fresh-water dissolution. In addition, the average salt precipitation rate in the northern and the southern parts of the lake is 466 and 266 times higher, respectively, than the average (0.3 mm/y) sedimentation rate before the lake shrinkage. Similar to other large hypersaline lakes such as the Great Salt Lake (USA) and the Aral Sea (Central Asia), the manmade intervention at Urmia Lake (damming of the catchment, extension of agricultural fields, and causeway construction in the middle part of the lake) threatens its further hydrologic existence.
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He, Anpeng, Xianqiang He, Yan Bai, Qiankun Zhu, Fang Gong, Haiqing Huang, and Delu Pan. "Simulation of Sedimentation in Lake Taihu with Geostationary Satellite Ocean Color Data." Remote Sensing 11, no. 4 (February 13, 2019): 379. http://dx.doi.org/10.3390/rs11040379.
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In this study, the goal is to estimate the sedimentation on the bottom bed of Lake Taihu using numerical simulation combined with geostationary satellite ocean color data. A two-dimensional (2D) model that couples the dynamics of shallow water and sediment transport is presented. The shallow water equations are solved using a semi-implicit finite difference method with an Alternating Direction Implicit (ADI) method. Suspended sediment transport is simulated by solving the general convection-diffusion equation with resuspension and deposition terms using a second-order explicit central difference method in space and two-step Adams–Bashforth method in time. Moreover, the total suspended particulate matter (TSM) is retrieved by the world’s first geostationary satellite ocean color sensor Geostationary Ocean Color Imager (GOCI) using atmospheric correction algorithm for turbid waters using ultraviolet wavelengths (UV-AC) and regional empirical TSM algorithm. The 2D model and GOCI-retrieved TSM are applied to study the sediment transport and sedimentation in Lake Taihu. Validation results show rationale TSM concentration retrieved by GOCI, and the simulated TSM concentrations are consistent with GOCI observations. In addition, simulated sedimentation results reveal the dangerous locations that must be observed and desilted.
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Kusumgar, Sheela, D. P. Agrawal, Narendra Bhandari, R. D. Deshpande, Alok Raina, Chhemendra Sharma, and M. G. Yadava. "Lake Sediments from the Kashmir Himalayas: Inverted 14C Chronology and Its Implications." Radiocarbon 34, no. 3 (1992): 561–65. http://dx.doi.org/10.1017/s0033822200063839.
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We have measured 14C, 210Pb and 137Cs profiles in two representative cores from Manasbal Lake, Kashmir, India. The sedimentation rate derived from 210Pb and 137Cs in the upper part of the core is in the range of 3.4 to 5.5 mm yr−1. In contrast, 14C ages show an inversion at depths >20 cm. These results are attributed to the erosion of the ubiquitous 10–20-m-thick loess mantle, based on the similarity of 14C ages of the inversion layer in the sediments and the paleosols present in the catchment area. Frequency-dependent mineral magnetic susceptibility (χfd), carbon to nitrogen ratios and pigment concentrations in the profile show a significant amount of allochthonous component in the lake deposits and support the conclusion that the 14C dates do not reflect the chronology of the in-situ lake sedimentation but episodic deposition of the surrounding loess. Thus, 14C serves as a useful tracer to understand source components of the sediments.
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Ludikova, Anna V. "Diatoms in the Early Valdai (Weichselian) sediments in Lake Ladoga basin." Issues of modern algology (Вопросы современной альгологии), no. 2(20) (2019): 225–28. http://dx.doi.org/10.33624/2311-0147-2019-2(20)-225-228.
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The pioneer diatom study of the Early Weichselian (Valdai) sediments in Lake Ladoga basin was performed. The specifics of the diatom assemblages (co-occurrence of ecologically incompatible taxa, poor species diversity, low diatom concentration and selective preservation) suggest that during the Early Weichselian time intense erosion of previously deposited marine Eemian (Mikulino) sediments prevailed, which resulted in re-deposition of marine diatoms. The sedimentation took place in high-energy environments unfavorable for diatom accumulation and preservation.
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Ross, Martin, Michel Parent, Beatriz Benjumea, and James Hunter. "The late Quaternary stratigraphic record northwest of Montréal: regional ice-sheet dynamics, ice-stream activity, and early deglacial events." Canadian Journal of Earth Sciences 43, no. 4 (April 1, 2006): 461–85. http://dx.doi.org/10.1139/e05-118.
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The Quaternary sediments of previously unstudied buried valleys and sections near Montréal are analyzed and other sites are revisited to further develop the stratigraphic framework of the St. Lawrence Lowland and to establish regional glacial and deglacial models. The southwest-trending buried valleys were investigated by stratigraphic drilling and high-resolution seismic profiling. The Quaternary succession consists, from base to top, of proximal glaciolacustrine sediments, two superposed till sheets (Argenteuil and Oka tills) of inferred Late Wisconsinan age, and Champlain Sea sediments. The glacial sediments of this sequence record an ice advance toward south (Argenteuil Till) followed by an abrupt ice-flow shift toward the southwest (Oka Till). Compositional and geomorphic data indicate that Oka Till is ubiquitous and is associated with a regional set of glacial landforms. The analysis of a regional digital elevation model in combination with published ice-flow indicators shows convergent flow patterns from the OttawaMontréalAdirondack regions toward the Lake Ontario basin. Landforms produced by the inferred ice stream are locally crosscut by southward-trending ice-flow features. Hence southward flow in the upper St. Lawrence Valley seemingly took place in two distinct contexts: (1) during full glacial conditions, as ice margins stood at or near the late glacial maximum limits, and (2) during late deglaciation, as a post-ice stream reequilibration mechanism. Early deglacial events in the study area were also characterized by subglacial meltwater channelling and erosion along the valleys, subaquatic outwash deposition in glacial Lake Candona, and rapid infill of the valleys during the early stages of the ensuing Champlain Sea.
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Vähäkuopus, Tuija, Tommi Kauppila, Jari Mäkinen, Antti E. K. Ojala, and Samu E. Valpola. "Sedimentation Patterns of Multiple Finnish Lakes Reveal the Main Environmental Stressors and the Role of Peat Extraction in Lake Sedimentation." Geosciences 10, no. 8 (August 13, 2020): 313. http://dx.doi.org/10.3390/geosciences10080313.
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Human land-use activities, especially in the peatlands, are under consideration as the mitigation and lowering of CO2 emissions from land-use practices is needed to address climate change. In Finland, approximately one third of the land surface is covered by peatlands, and around 50% of peatlands are ditched for forestry. Another 3% of peatlands are used for agriculture and approximately 1% for peat extraction. The effects of these different land-use practices, including changes in sediment depositional rates and sediment quality, need to be identified. This study analyzed 51 lakes that were subdivided into two groups: (1) a group of impacted lakes in which peat was recently extracted from the catchments and (2) a reference group consisting of lakes where peat had not been extracted from the basin, but in which other land-use activities had occurred. The overall aim of the study was to investigate if peat extraction caused excessive delivery and deposition of dry and organic matter in lakes that are located in their immediate downstream catchment areas. Differences in sediment accumulation were defined by comparing the overall sediment thickness and recent (post 1986) sedimentation levels to identify if there were differences in the sediment chemical composition or rate of organic matter deposition between groups and to identify possible land-use stressors that could explain the possible differences in sediment chemical assemblages or sedimentation rates. The results show moderate (cm scale) sedimentation rates in both impacted and reference lakes after 1986, while sediment chemical assemblages indicated the erosion and input of mineral soils to all of the studied lakes, rather than the input of organic materials. No statistically significant correlations were observed between selected environmental variables and the recent accumulation rates of carbon and dry matter. Moreover, significant changes in the stressors potentially affecting the chemical assemblages of pre- and post-disturbance sediments were not observed.
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Peramaki, Liisa, and Michael Stone. "Fluxes of As, Cu, Hg, Pb in lake sediments in the Coppermine River basin, Canada." Hydrology Research 38, no. 2 (April 1, 2007): 177–85. http://dx.doi.org/10.2166/nh.2007.006.
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Many watersheds in northern Canada are experiencing increasing pressures from resource extraction, development and the long-range transport of atmospheric pollutants. This study examines sediment accumulation and the spatial and temporal distribution of trace metals in bottom sediment of down gradient lakes in the headwaters of the Coppermine River basin, Canada. Sediment cores were collected from Lac de Gras, Desteffany Lake, Point Lake and Daring Lake using a plastic lined K–B single-gravity corer. Each core was dated using 210Pb and concentrations of trace metals (As, Cu, Hg, Pb) were determined in core sections. Sedimentation rates ranged from 101 g m−2 yr−1 at Desteffany Lake to 156 g m−2 yr−1 at Daring Lake and are comparable to other northern lakes. Concentrations of As and Cu were significantly higher at Lac de Gras. Metal loading data and enrichment ratios show that concentrations of Pb and Hg are elevated compared to historic background levels. Metal enrichment is from anthropogenic activities and atmospheric inputs. Lake sediment represents a good indicator of state for the Coppermine basin and documents historic trends of metal deposition. However, the indicator has low sensitivity to change and coarse temporal resolution due to low sedimentation rates in northern environments.
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Hurley, James P., and Paul J. Garrison. "Composition and Sedimentation of Aquatic Pigments Associated with Deep Plankton in Lakes." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 12 (December 1, 1993): 2713–22. http://dx.doi.org/10.1139/f93-296.
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High Performance Liquid Chromatography (HPLC) pigment techniques were applied to study planktonic pigment composition and sedimentation in four Wisconsin (USA) lakes. In each lake, deep blooms of phytoplankton overlaid phototrophic sulfur bacteria in the region of the oxic-anoxic interface. Chlorophyll a and bacteriochtorophyll (a, d, and e) were observed as indicators of phytoplankton and phototrophic sulfur bacteria, respectively. Major taxonomic classes of phytoplankton were further resolved based on carotenoid signatures. In contrast to three oligo-mesotrophic Wisconsin lakes in which deep phytoplankton were comprised of dinoflagellates (indicated by the carotenoids peridinin, diadinoxanthin), cryptophytes (alloxanthin), and chrysophytes (fucoxanthin), the deep phytoplankton community in mesotrophic Mirror Lake was dominated by blue-green algae (oscillaxanthin, myxoxanthophyll, zeaxanthin, and echinenone). Deep planktonic production strongly influenced sedimentation of algal pigments and obscured the relationship between apparent water quality and sedimentary pigment deposition.
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Barnett, Peter J., and Paul F. Karrow. "Ice-marginal sedimentation and processes of diamicton deposition in large proglacial lakes, Lake Erie, Ontario, Canada." Canadian Journal of Earth Sciences 55, no. 7 (July 2018): 846–62. http://dx.doi.org/10.1139/cjes-2017-0006.
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Detailed studies of coastal cliff exposures through two end moraines form the basis for a model of ice-marginal sedimentation in large ice-contact glacier-fed lakes. The input to the ice-marginal environment directly from the glacier included subglacial till and subaquatic flow tills. The subaquatic flow till (thinly bedded diamicton) was deposited in an apron (up to 1 km wide) along the ice margin. An upward gradient of pore-water pressure immediately beyond the ice margin, causing heaving and dilation of the sediments, initiated debris flows of glacially derived debris (subaquatic flow tills). Most of the stratified sediments in the ice-marginal zone entered the lake by way of a large proglacial stream. Sedimentation was dominated by quasi- or near-continuous density underflows that resulted in the deposition of a sequence of thick rhythmites. The glacier in the Lake Erie basin most likely behaved like an ice stream, with its movement controlled predominantly by a deforming bed of glacial debris, separating the glacier sole from underlying predeposited sediments. The deforming bed is preserved as a massive diamicton layer, interpreted here as subglacially deposited till.
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Hanson, Michelle Andrée, Randolph Jonathan Enkin, René William Barendregt, and John Joseph Clague. "Provenance and Deposition of Glacial Lake Missoula Lacustrine and Flood Sediments Determined from Rock Magnetic Properties." Quaternary Research 83, no. 1 (January 2015): 166–77. http://dx.doi.org/10.1016/j.yqres.2014.09.005.
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AbstractRepeated outburst flooding from glacial Lake Missoula, Montana, affected large areas of Washington during Marine Oxygen Isotope Stage 2 (29–14 ka). We present the first high-resolution rock magnetic results from two sites that are critical to interpreting these outburst floods and that provide evidence of sediment provenance: glacial Lake Missoula, the source of the floods; and glacial Lake Columbia, where floodwaters interrupted sedimentation. Magnetic carriers in glacial Lake Missoula varves are dominated by hematite, whereas those in outburst flood sediments and glacial Lake Columbia sediments are mainly magnetite and titano-magnetite. Stratigraphic variation of magnetic parameters is consistent with changes in lithology. Importantly, magnetic properties highlight depositional processes in the flood sediments that are not evident in the field. In glacial Lake Columbia, hematite is present in fine silt and clay deposited near the end of each flood as fine sediment settled out of the water column. This signal is only present at the end of the floods because the hematite is concentrated in the finer-grained sediment transported from the floor of glacial Lake Missoula, the only possible source of hematite, ~ 240 km away.
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Iradukunda, Parfait, and Maurice O. Nyadawa. "Impact of Sedimentation on Water Seepage Capacity in Lake Nakuru, Kenya." Applied and Environmental Soil Science 2021 (February 16, 2021): 1–10. http://dx.doi.org/10.1155/2021/8889189.
Full textAbstract:
Accumulation and deposition of sediments in waterbody affect the seepage capacity that could lead to improper water balance and results in the water level rise. This study analysed the influence of sedimentation on seepage capacity in Lake Nakuru and the impact of sediment characteristics to the water seepage and the flow rate formation at the lake bed level. The study was performed by sampling and analysing the sediment cores from two locations in the lake. The sediment hydraulic properties, i.e., moisture and porosity, particle sizes, and hydraulic conductivity, were determined using the oven-drying method, sieve analysis, hydrometer analysis, and falling head tests, respectively. The results showed that the lake sediment sample from location P1 had an average ratio of 39.38% for silty soil, 34.00% for clayey sediment, and 26.63% for fine-sand sediment particles with the maximum permeability coefficient of 3.37 ∗ 10 − 5 cm/s, while the one from location P2 had an average ratio of 63.17% for sand, 20.17% for fine particles, and 16.67% for gravels with the maximum permeability coefficient of 0.010793 cm/s. The hydraulic conductivity of sediment sample from location P1 and P2 increased along the core depth. This could lead to the rise of water level due to the decreases of water movement induced from the sediment cementation in the top layers under the waterbody. Sedimentation affects Lake Nakuru water volume and water balance; hence, there is a need to control the inflow of sediment resulting from anthropogenic activities in the watershed.
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Corfu, F., and R. P. Sage. "U–Pb age constraints for deposition of clastic metasedimentary rocks and late-tectonic plutonism, Michipicoten Belt, Superior Province." Canadian Journal of Earth Sciences 29, no. 8 (August 1, 1992): 1640–51. http://dx.doi.org/10.1139/e92-129.
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The study investigates the ages of clastic metasedimentary rocks and of late-tectonic alkalic to calc-alkalic intrusions and puts constraints on the timing of major deformation in the Michipicoten greenstone belt of the Wawa Subprovince. A trondhjemitic boulder in the Doré conglomerate of the southern metasedimentary belt is dated at 2698 ± 2 Ma. This is a maximum age of sedimentation that is also supported by ages of detrital zircons in the matrix and may directly reflect the time of synvolcanic deposition. Detrital zircons in metapsammites of the central and northern sedimentary belts yield younger ages of 2682 ± 3 and 2680 ± 3 Ma, respectively, suggesting that sedimentation occurred significantly later in the northern than in the southern parts of the greenstone belt. The ≤2682 Ma sedimentary rocks were affected by multiphase deformation that is related to the development of a large-scale recumbent fold and superimposed folds and faults. This tectonism was followed by the emplacement of the granodioritic Troupe Lake and Maskinonge Lake stocks that yield identical zircon and titanite ages of 2671 ± 2 Ma. The structurally older and deformed Herman Lake nepheline syenite has an imprecise titanite age of [Formula: see text]. The isotopic composition of Pb in feldspar of these intrusions is relatively evolved and, in light of geochemical considerations, may reflect provenance of the melts from enriched mantle reservoirs.
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Zhang, Yunlong, Zhidong Bao, Luxing Dou, Li Jiang, Mingyang Wei, and Li Zhang. "Hydrodynamics and deposition in lacustrine shallow-water delta front: A combination of numerical simulations and modern sedimentation measurements." Interpretation 8, no. 3 (August 1, 2020): SM39—SM52. http://dx.doi.org/10.1190/int-2019-0176.1.
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With the exploration of tight oil and gas, shallow-water deltaic reservoirs have been attracting more and more attention. The sedimentary architecture of a shallow-water delta shows distinctive differences with that of a deep-slope delta. These differences may be associated with the mechanism and characteristics of the deposition in the area where the sediments unloaded. Based on modern sedimentary research of the Poyang Lake in China, this paper focuses on the processes of river flow entering a lake with a low dip angle. We conducted six sets of numerical simulations with different initial sedimentary flow velocities using Fluent software for analyzing the hydrodynamics and the sediment transportation in the shallow-water delta. We combined the simulation results with an analysis of the geomorphology of the Gangjiang Delta to reveal the deposition along the shoreline of the lacustrine shallow-water delta. The numerical simulation shows that the shallow-water delta is dominated by bed friction with an extensive hydrodynamical boundary layer. The bed shear stress, which varies with the changes in river flux, dominated the sediment transport and deposition at the shallow-water delta front, where the effluent flow mixes with lake water. The distributary channels show characteristics of repeatedly occurred erosion, scouring, filling, and reoccupation. We argue that the depositional characteristics are associated with the changes in bed shear stress controlled by variation of flow velocity. Mouth bars are less likely to grow to a reasonable scale because of the seasonal scouring of extreme floods. Moreover, the lake flow potentially reworks the mouth bars. Consequently, mouth bar deposits were difficult to preserve as hydrocarbon reservoirs in ancient shallow-water delta.
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Apak, S. N., W. J. Stuart, and N. M. Lemon. "COMPRESSIONAL CONTROL ON SEDIMENT AND FACIES DISTRIBUTION SW NAPPAMERRI SYNCLINE AND ADJACENT MURTEREE HIGH, COOPER BASIN." APPEA Journal 35, no. 1 (1995): 190. http://dx.doi.org/10.1071/aj94013.
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The northeast-trending Nappamerri Syncline and its flanking high to the southeast, the Murteree-Nappacoongee (NM) Trend, show structural development throughout the deposition of the Permo-Triassic Cooper Basin sequences. Pre-existing topography, such as around Moomba, influenced early depositional patterns within the area. Rates of sedimentation were influenced by the rate of uplift of source areas around the basin, largely as a consequence of buckling. Periods of active tectonism resulted in non-deposition and stripping of sediments from uplifted blocks while deposition continued in deeper areas. Hangingwall blocks, pushed up along reverse faults, strongly influenced the areas of sedimentation and the facies being deposited. This is particularly evident along the NM Trend. Phases of uplift were immediately followed by increased sedimentation where fluvial deposition dominated. The effect of displacement along the northwest-trending basement lineaments was to subdivide the northeast trends into compartments which contain similar facies within each time slice. Adjacent compartments may display different facies and different tectonic histories. An inversion episode, particularly evident in the Big Lake/Moomba area, resulted in a reversal of the depocentre and was related to phases of Sakmarian compression.Facies distribution and sandstone percentage maps of the chronostratigraphic units of the Patchawarra Formation suggest that a northeast-trending major channel system entered this part of basin along the NW edge of the Murteree area.
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Wolfe, Brent, and James T. Teller. "Sedimentation in Ice-Damned Glacial Lake Assiniboine, Saskatchewan, and Catastrophic Drainage Down the Assiniboine Valley." Géographie physique et Quaternaire 49, no. 2 (November 30, 2007): 251–63. http://dx.doi.org/10.7202/033040ar.
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ABSTRACTIce-dammed glacial Lake Assiniboine covered approximately 1500 km2in eastern Saskatchewan at about 11,000 BP. Lithofacies in two cores from the lake basin were identified, correlated, and linked to paleolake strandlines and inflow and outflow channels discerned from aerial photos and surface mapping. Deeper lake stages are reflected by silt and clay varve deposition in the deepest part of the basin, whereas shallower stages are represented by fluctuating grain size and current-generated sedimentary structures in sediments nearer to where influxes of melt-water occurred. The stratigraphie record revealed six lake phases, beginning with a shallow period when water collected in the interlobate area between ice on the Duck Mountain Upland to the east and the Assiniboine Ice Lobe to the west. A rise in lake level to about 495 m occurred as the southern outlet was dammed by ice. After about 85 varve years, waters from the Porcupine Hills Upland to the north flooded into glacial Lake Assiniboine, perhaps as a result of the drainage of an ice marginal lake, causing erosion at the lake's southern outlet and a drop in lake level. A second major influx of water from the Porcupine Hills area, at least 20 varve years later, led to downcutting of the outlet and draining of Lake Assiniboine. Shallow and deep channels, streamlined hills, and scattered boulders adjacent to the now-entrenched Assiniboine valley at the former outlet of glacial Lake Assiniboine suggest that the lake drained catastrophically. Similar geomorphic features at sites downstream along the Assiniboine valley are also indicative of catastrophic flow, although only those areas north of the Qu'Appelle River spillway junction are predominantly attributed to outbursts from glacial Lake Assiniboine.
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Corfu, Fernando, and Shoufa Lin. "Geology and U-Pb geochronology of the Island Lake greenstone belt, northwestern Superior Province, Manitoba." Canadian Journal of Earth Sciences 37, no. 9 (September 1, 2000): 1275–86. http://dx.doi.org/10.1139/e00-043.
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Mapping and U-Pb geochronology have been used to examine the tectonic and depositional history of the Archean Island Lake greenstone belt in the northwestern Superior Province. The Island Lake greenstone belt comprises two main supracrustal successions, the older Hayes River Group and the younger Island Lake Group. Zircon data for two volcanic units from the Hayes River Group provide identical ages of 2852 ± 1.5 Ma, whereas a turbidite of this group contains a detrital zircon population with ages between 2858 and 2847 Ma. Younger intrusive events include the emplacement of tonalite in the southern batholith at 2825 ± 2 Ma and the Whiteway Island gabbro at 2807 ± 1 Ma. A wacke at the base of the Island Lake Group is dominated by detrital zircon grains yielding ages between 2830 and 2821 Ma, the latter defining a maximum age of sedimentation. A relatively early time of deposition of the lower stratigraphic sections of the Island Lake Group is also supported by an age of 2744 ± 2 Ma obtained for a crosscutting tonalite. By contrast, two turbidite horizons from higher stratigraphic levels of the Island Lake Group contain detrital zircon populations with ages mostly younger than 2730 Ma, the youngest zircon grains providing maximum ages of sedimentation at 2722 and 2712 Ma, respectively. Our results confirm the protracted evolution of the greenstone belt and show in particular that major sedimentary processes were active throughout the main stages of volcanism of the belt. This pattern of protracted sedimentation is comparable to that observed in other greenstone belts of the northwestern Superior Province, all of which developed on pre-Kenoran crust.
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Clark, Peter U., Susan K. Short, Kerstin M. Williams, and John T. Andrews. "Late Quaternary chronology and environments of Square Lake, Torngat Mountains, Labrador." Canadian Journal of Earth Sciences 26, no. 10 (October 1, 1989): 2130–44. http://dx.doi.org/10.1139/e89-179.
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Sediment, pollen, and diatom records from Square Lake, a small lake dammed by a segment of Saglek Moraine, cover the period of deposition of and deglaciation from the Saglek Moraine. The basal radiocarbon date (18 210 ± 1900 years BP) is on sediment contaminated by reworked pollen and is thus a maximum age. However, the date was measured on organic carbon recovered from glaciolacustrine couplets associated with deposition of the Saglek Moraine and thus establishes a Late Wisconsinan age for the Saglek Moraine. Vegetation on the ice-free upland surrounding Square Lake at this time was a sparse tundra vegetation dominated by grasses and herbs. The absence of diatoms indicates perennial lake-ice cover. A major transition is recorded by pollen and diatoms at > 8.5 ka. Vegetation probably remained sparse tundra, but birch and willow may have arrived in the area by 8 ka. Diatoms are first dominated by alkaliphil species, reflecting continued influence of glaciolacustrine sedimentation. An abrupt change in depositional environment ≥ 8 ka indicates ice retreat from the Saglek Moraine and start of nonglacial lacustrine sedimentation that has continued to the present. This was accompanied by an increase in organic matter, reflecting the newly established rich shrub tundra. At this time the diatoms also change, suggesting development of acidic organic soils around the lake. At 7.5 ka, diatoms indicate continued evolution of water chemistry and nutrient availability in the lake. Diatom concentrations and transfer function analyses of the pollen record identify the Holocene climatic optimum at 6.5 ka in the southern Torngat Mountains. The modern diatom flora was established at that time, but a decrease in diatom concentrations and estimated July temperatures suggest climatic deterioration in the area since 6.5 ka.
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Mu’min, Risqa Permatasyara, A. M. Imran, and Safruddim. "Sedimentation mechanism and provenance of sediment deposition in Sidenreng Lake, Sidrap District, South Sulawesi Province." IOP Conference Series: Earth and Environmental Science 575 (October 29, 2020): 012208. http://dx.doi.org/10.1088/1755-1315/575/1/012208.
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Shevchenko, Vladimir P., Dina P. Starodymova, Sergey N. Vorobyev, Ramiz A. Aliev, Lyudmila P. Borilo, Larisa G. Kolesnichenko, Artyom G. Lim, Andrey I. Osipov, Vladislav V. Trufanov, and Oleg S. Pokrovsky. "Trace Elements in Sediments of Two Lakes in the Valley of the Middle Courses of the Ob River (Western Siberia)." Minerals 12, no. 12 (November 24, 2022): 1497. http://dx.doi.org/10.3390/min12121497.
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Lake sediments accumulate various pollutants and act as efficient natural archives suitable for reconstruction the environmental conditions of the past. In contrast to fairly good knowledge of mineral sediments in lakes of European and North America boreal lakes, Siberian lakes of the boreal zone remain quite poorly studied. In this work, two cores of lake sediments of the Ob River valley were investigated. Elemental analyses were carried out on the sediments, losses on ignition were determined, and the rate of sedimentation was measured from the activity of Pb-210 and Cs-137. According to the content of organic matter, bottom sediments belong to different types: clastic (Lake Inkino, located in the Ob River floodplain) and organogenic (Lake Shchuchie on the second terrace). The rate of sedimentation in Lake Shchuchie is several times higher than that in Lake Inkino. The sediments of Lake Inkino are similar in composition (including the pattern of rare earth elements) to the suspended particulate matter of the Ob River as well as to average detrital matter of the upper continental crust. Sediments of Lake Shchuchie (sapropels) are enriched in a number of heavy metals. Based on the elemental composition, signs of diagenetic processes and authigenic mineral formation were determined, such as accumulation of carbonates and the formation of manganese oxides and hydroxides. There is an enhanced recent input of Cr, Co, Cu, Zn, Cd, Sb, Pb, and Bi in the upper layers of sediments as a result of atmospheric anthropogenic pollutant deposition.
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Evans, David JA, Keith E. Salt, and Claire S. Allen. "Glacitectonized lake sediments, Barrier Lake, Kananaskis Country, Canadian Rocky Mountains." Canadian Journal of Earth Sciences 36, no. 3 (March 25, 1999): 395–407. http://dx.doi.org/10.1139/e98-093.
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Stratigraphic and sedimentological analyses of exposures through a glacilacustrine sedimentary sequence along the south shore of Barrier Lake, Kananaskis Country, reveal evidence of glacitectonic disturbance, relating to a readvance of the Bow Valley glacier at the end of the last glaciation. Prior to disturbance, palaeocurrent measurements in gravel and sand foreset beds record the deposition of subaqueous fans-deltas from a glacier lobe retreating eastwards along the Barrier Lake depression. The fan-delta sediments fine upwards into ripple- and cross-bedded sands and laminated muds with dropstones, documenting progressively distal sedimentation. Palaeostress directions measured from large-scale folds, shear zones and glacitectonites, and deformation tills indicate that glacier ice readvanced southwards from a glacier lobe located over the Barrier Lake depression. These stress directions are used to reconstruct the flow lines within the southern margin of a low-profile glacier lobe that terminated halfway up lower Barrier Lake, a more extensive readvance than previously envisaged in the area for this period. Comparisons of diamicton and glacitectonite fabric shapes with similar sediments elsewhere indicate that the subglacially deformed material that caps some of the sections is immature and has undergone short travel distances. Although the exact age of the readvance is unknown, it probably represents the Canmore Readvance of the Late Wisconsinan glaciation.
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Dietze, E., F. Maussion, M. Ahlborn, B. Diekmann, K. Hartmann, K. Henkel, T. Kasper, G. Lockot, S. Opitz, and T. Haberzettl. "Sediment transport processes across the Tibetan Plateau inferred from robust grain-size end members in lake sediments." Climate of the Past 10, no. 1 (January 16, 2014): 91–106. http://dx.doi.org/10.5194/cp-10-91-2014.
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Abstract. Grain-size distributions offer powerful proxies of past environmental conditions that are related to sediment sorting processes. However, they are often of multimodal character because sediments can get mixed during deposition. To facilitate the use of grain size as palaeoenvironmental proxy, this study aims to distinguish the main detrital processes that contribute to lacustrine sedimentation across the Tibetan Plateau using grain-size end-member modelling analysis. Between three and five robust grain-size end-member subpopulations were distinguished at different sites from similarly–likely end-member model runs. Their main modes were grouped and linked to common sediment transport and depositional processes that can be associated with contemporary Tibetan climate (precipitation patterns and lake ice phenology, gridded wind and shear stress data from the High Asia Reanalysis) and local catchment configurations. The coarse sands and clays with grain-size modes >250 μm and <2 μm were probably transported by fluvial processes. Aeolian sands (~200 μm) and coarse local dust (~60 μm), transported by saltation and in near-surface suspension clouds, are probably related to occasional westerly storms in winter and spring. Coarse regional dust with modes ~25 μm may derive from near-by sources that keep in longer term suspension. The continuous background dust is differentiated into two robust end members (modes: 5–10 and 2–5 μm) that may represent different sources, wind directions and/or sediment trapping dynamics from long-range, upper-level westerly and episodic northerly wind transport. According to this study grain-size end members of only fluvial origin contribute small amounts to mean Tibetan lake sedimentation (19± 5%), whereas local to regional aeolian transport and background dust deposition dominate the clastic sedimentation in Tibetan lakes (contributions: 42 ± 14% and 51 ± 11%). However, fluvial and alluvial reworking of aeolian material from nearby slopes during summer seems to limit end-member interpretation and should be crosschecked with other proxy information. If not considered as a stand-alone proxy, a high transferability to other regions and sediment archives allows helpful reconstructions of past sedimentation history.
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Dietze, E., F. Maussion, M. Ahlborn, B. Diekmann, K. Hartmann, K. Henkel, T. Kasper, G. Lockot, S. Opitz, and T. Haberzettl. "Sediment transport processes across the Tibetan Plateau inferred from robust grain size end-members in lake sediments." Climate of the Past Discussions 9, no. 4 (August 21, 2013): 4855–92. http://dx.doi.org/10.5194/cpd-9-4855-2013.
Full textAbstract:
Abstract. Grain size distributions offer powerful proxies of past environmental conditions that are related to sediment sorting processes. However, they are often of multimodal character because sediments can get mixed during deposition. To facilitate the use of grain size as palaeoenvironmental proxy this study aims to distinguish the main detrital processes that contribute to lacustrine sedimentation across the Tibetan Plateau using grain size end-member modelling analysis. Between three and five robust grain size end-member subpopulations were distinguished at different sites from similarly-likely end-member model runs. Their main modes were grouped and linked to sediment transport and depositional processes associated with certain climatic background and catchment configurations. The coarse sands and clays with grain size modes > 250 μm and < 2 μm were probably transported by fluvial processes. Aeolian sands (~ 200 μm) and coarse local dust (~ 60 μm), transported by saltation and in near-surface suspension clouds, are probably related to occasional westerly storms in winter and spring. Coarse regional dust with modes ~ 25 μm may derive from near-by sources that keep in longer-term suspension. The continuous background dust is differentiated into two robust end-members (modes: 5–10 and 2–5 μm) that may represent different sources, wind directions and/or sediment trapping dynamics from long-range, upper-level westerly and episodic northerly wind transport. According to this study grain size end-members of only fluvial origin contribute small amounts to mean Tibetan lake sedimentation (19 ± 5%), whereas local to regional aeolian transport and background dust deposition dominate the clastic sedimentation in Tibetan lakes (contributions: 42 ± 14% and 51 ± 11%). However, fluvial and alluvial reworking of aeolian material from nearby slopes during summer seems to limit end-member interpretation and should be crosschecked with other proxy information. If not considered as a stand-alone proxy, a high transferability to other regions and sediment archives allows helpful reconstructions of past sedimentation history.