Sediment accumulation and sedimentation rates in playas on the High Plains of western Kansas, USA

Geomorphology ◽  
2019 ◽  
Vol 342 ◽  
pp. 117-126
Author(s):  
Mark W. Bowen ◽  
William C. Johnson
Keyword(s):  
Sediment Accumulation ◽  
High Plains ◽  
Sedimentation Rates

Distribution of biogenic silica in the surficial sediments of Lake Michigan

1986 ◽  
Vol 23 (9) ◽  
pp. 1442-1449 ◽  
Author(s):  
Daniel J. Conley ◽  
Claire L. Schelske ◽  
Brian G. Dempsey ◽  
Charles D. Campbell ◽  
Teresa L. Newberry
Keyword(s):  
Spatial Distribution ◽  
Biogenic Silica ◽  
Lake Michigan ◽  
Sediment Accumulation ◽  
Sedimentation Rates ◽  
Surficial Sediments ◽  
Sediment Samples ◽  
High Productivity ◽  
Lake Bottom ◽  
High Concentrations

The spatial distribution of biogenic silica (BSi) in the surficial sediments of Lake Michigan is described from Shipek grab samples collected in 1975 and gravity cores obtained in 1983. Significantly smaller surficial BSi concentrations in the 1975 samples were attributed primarily to the inability of a Shipek grab to collect intact surficial sediment samples. Lower concentrations o.f BSi were found in nondepositional and transitional areas of sediment accumulation than in depositional basins. Therefore, BSi accumulation is restricted primarily to the 40% of the lake bottom where sediments are presently accumulating. High concentrations found in Green Bay surficial sediments are related to high productivity in the bay coupled with inputs of new silica from the Fox River. In the open lake, BSi concentrations of surficial sediments in depositional basins appeared to vary inversely with sedimentation rate in that lower BSi concentrations were found in areas with higher sedimentation rates.

scholarly journals Long- to short-term denudation rates in the southern Apennines: geomorphological markers and chronological constraints

2011 ◽  
Vol 62 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Dario Gioia ◽  
Claudio Martino ◽  
Marcello Schiattarella
Keyword(s):  
Sediment Accumulation ◽  
Radiometric Dating ◽  
Sedimentation Rates ◽  
Southern Apennines ◽  
Short Term ◽  
Small Catchment ◽  
Fluvial Terraces ◽  
Denudation Rates ◽  
Land Surfaces

Long- to short-term denudation rates in the southern Apennines: geomorphological markers and chronological constraints Age constraints of geomorphological markers and consequent estimates of long- to short-term denudation rates from southern Italy are given here. Geomorphic analysis of the valley of the Tanagro River combined with apatite fission track data and radiometric dating provided useful information on the ages and evolution of some significant morphotectonic markers such as regional planated landscapes, erosional land surfaces and fluvial terraces. Reconstruction of paleotopography and estimation of the eroded volumes were perfomed starting from the plano-altimetric distribution of several orders of erosional land surfaces surveyed in the study area. Additional data about denudation rates related to the recent and/or active geomorphological system have been obtained by estimating the amount of suspended sediment yield at the outlet of some catchments using empirical relationships based on the hierarchical arrangement of the drainage network. Denudation rates obtained through these methods have been compared with the sedimentation rates calculated for two adjacent basins (the Pantano di San Gregorio and the Vallo di Diano), on the basis of published tephrochronological constraints. These rates have also been compared with those calculated for the historical sediment accumulation in a small catchment located to the north of the study area, with long-term exhumation data from thermochronometry, and with uplift rates from the study area. Long- and short-term denudation rates are included between 0.1 and 0.2 mm/yr, in good agreement with regional data and long-term sedimentation rates from the Vallo di Diano and the Pantano di San Gregorio Magno basins. On the other hand, higher values of exhumation rates from thermochronometry suggest the existence of past erosional processes faster than the recent and present-day exogenic dismantling. Finally, the comparison between uplift and denudation rates indicates that the fluvial erosion did not match the tectonic uplift during the Quaternary in this sector of the chain. The axial zone of the southern Apennines should therefore be regarded as a landscape in conditions of geomorphological disequilibrium.

Time averaging and stratigraphic unmixing: reconstructing ecological decline in molluscan production (Holocene, Brijuni, NE Adriatic)

2020 ◽  
Author(s):  
Adam Tomašových ◽  
Martin Zuschin ◽  
Ivo Gallmetzer ◽  
Alexandra Haselmair
Keyword(s):  
Accumulation Rate ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Coralline Algae ◽  
Time Averaging ◽  
Sedimentation Rates ◽  
Amino Acid Racemization ◽  
Ecological History ◽  
Shell Bed ◽  
Warm Temperate

<p>The northeastern Adriatic seafloor is formed by warm-temperate bioclastic carbonates with coralline algae, bryozoans and mollusks. These sediments represent a mixture of past and present-day production owing to low sedimentation rates and bioturbation. Although low sedimentation rates do not allow resolution of ecological history at centennial or even millennial scales on the basis of raw stratigraphic data, age unmixing based on radiocarbon-calibrated amino acid racemization shows that one of the major molluscan sediment producers – the infaunal suspension-feeder Timoclea ovata  – markedly peaked in production ~5,000 years during the maximum flooding and earliest highstand phase and significantly diminished in abundance during the late highstand phase at Brijuni, with a large proportion of dead shells now present in surface sediments representing shells that are several centuries old. This species still occurs in living assemblages but our analyses indicate that its former production was by several orders of magnitude higher. In contrast, stratigraphic trends in absolute and proportional abundance of this species in ~1.5 m-thick sediment cores show a gradual or a very mild upcore decline, indicating that raw stratigraphic data do not efficiently detect millennial-scale ecological dynamic. The temporal decline in production of Timoclea ovata is associated with an increase in water depth and an increase in sediment-accumulation rate, and led to a transition from molluscan oyster-scallop shell bed to late highstand bryomol sediments.</p>

Radiocarbon dating and sedimentation rates in the Holocene alluvial sediments of the northern Bihar plains, India

1996 ◽  
Vol 133 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Rajiv Sinha ◽  
Peter F. Friend ◽  
V. R. Switsur
Keyword(s):  
Sediment Accumulation ◽  
Uttar Pradesh ◽  
Foreland Basin ◽  
Sedimentation Rates ◽  
Near Surface ◽  
Radiocarbon Dates ◽  
Gangetic Plains ◽  
River Terraces ◽  
Short Period ◽  
Two Samples

AbstractSeven radiocarbon dates of carbonate shells and charcoal from the upper two metres of sediment in the Indo-Gangetic plains of northern Bihar, eastern India, can be divided into three groups, with the following approximate ages: 2400±45 a BP (two samples), 1100±45 a BP (four samples) and 765±45 a BP (one sample). This evidence for at least three episodes of sedimentation in the last 2400 a contrasts with evidence of greater ages from similarly near-surface sediments in the middle Gangetic plains of Uttar Pradesh, further west. In these more westerly areas, greater ages and well-developed river terraces point to much more restricted late Holocene sedimentation. Rates of net sediment accumulation calculated using our Bihar ages, spanning a period of the order of 103–104 a, are similar to those calculated for periods of the order of 105–106 a for the Himalayan foreland basin. This suggests that, in the whole basin case, short-period rates higher than the Bihar rates have been compensated by longer than Bihar periods of non-deposition or erosion.

scholarly journals Modeling of Sediment Transport in Bothnian Bay in the Vicinity of the Nuclear Power Plant ‘Hanhikivi-1’ Construction Site

2019 ◽  
Vol 7 (7) ◽  
pp. 229 ◽  
Author(s):  
Stanislav D. Martyanov ◽  
Anton Yu. Dvornikov ◽  
Vladimir A. Ryabchenko ◽  
Dmitry V. Sein
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Sediment Accumulation ◽  
Middle Part ◽  
Sedimentation Rates ◽  
Northern Coast ◽  
Coupled Modeling ◽  
North East ◽  
Bothnian Bay

The intensity of sediment resuspension and sedimentation in the eastern part of the Bothnian Bay near the Hanhikivi cape, where the nuclear power plant ‘Hanhikivi-1’ will be constructed, has been assessed for the first time by means of numerical modeling under the realistic external forcing that occurred in 2014. A brief description of a coupled modeling system used in the study is given. The results of local resuspension intensity and sediment accumulation rates for one-year model run are presented. It has been determined that the main areas of sediment accumulation are located along the northern coast off the Hanhikivi peninsula and in the shallow region situated to the north-east off the cape. Sedimentation rates in the navigation channel have also been estimated. Model results obtained for 2014 suggest that sedimentation in the seaward part of the channel is absent, while sediment accumulation intensity is about 10 cm/year in the middle part of the channel and 70 cm/year in the coastal part. A temporal variability of the sedimentation rates during the year has been emphasized.

scholarly journals Sedimentation Patterns of Multiple Finnish Lakes Reveal the Main Environmental Stressors and the Role of Peat Extraction in Lake Sedimentation

Geosciences ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 313
Author(s):  
Tuija Vähäkuopus ◽  
Tommi Kauppila ◽  
Jari Mäkinen ◽  
Antti E. K. Ojala ◽  
Samu E. Valpola
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Land Surface ◽  
Reference Group ◽  
Sediment Quality ◽  
Sediment Accumulation ◽  
Sedimentation Rates ◽  
Peat Extraction ◽  
Catchment Areas ◽  
Land Use Practices

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.

Effects of agricultural tillage and sediment accumulation on emergent plant communities in playa wetlands of the U.S. High Plains

2013 ◽  
Vol 120 ◽  
pp. 10-17 ◽  
Author(s):  
Jessica L. O'Connell ◽  
Lacrecia A. Johnson ◽  
Dale W. Daniel ◽  
Scott T. McMurry ◽  
Loren M. Smith ◽  
...  
Keyword(s):  
Plant Communities ◽  
Sediment Accumulation ◽  
High Plains ◽  
Playa Wetlands ◽  
The U.S

Holocene sedimentation in glacial Tasikutaaq Lake, Baffin Island

1988 ◽  
Vol 25 (6) ◽  
pp. 810-823 ◽  
Author(s):  
Donald S. Lemmen ◽  
Robert Gilbert ◽  
John P. Smol ◽  
Roland I. Hall
Keyword(s):  
Drainage Basin ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Late Glacial ◽  
Sediment Concentration ◽  
Diatom Assemblage ◽  
Laminated Sediments ◽  
Sedimentation Rates ◽  
Baffin Island ◽  
Sediment Input

Tasikutaaq Lake, on Cumberland Peninsula, Baffin Island, receives inflow and fine sediment from a 448 km2 drainage basin, 21% of which is glacier covered. During the summer of 1983 the lake remained essentially isothermal between about 4 and 6 °C. The suspended sediment concentration of inflow never exceeded 100 mg L−1 with overflow and homopycnal flow dominant.Surface sediments are clearly laminated, although varves are not apparent. The sediments are very fine, with less than 3% sand in all but the most proximal sites. Average sedimentation rates between 1976 and 1983 ranged from about 4 mm a−1 to 0.25 mm a−1 down lake from the point of inflow. The absence of varves is a function of the low rates of sediment accumulation and the long residence time of the fine sediments in the water column.Three sediment cores up to 135 cm in length reveal marked changes in sediment characteristics and diatom assemblages through the Holocene. During the late Foxe Glaciation it is likely that glacier ice contacted the lake, with retreat upvalley recorded by thinly varved (?) silts. By 7580 ± 140 BP ice had retreated to near its present margins. The earliest diatom assemblage in the cores is dominated by small Fragilaria spp., typical of late glacial, pioneering environments. Sedimentation rates during much of the Hypsithermal were about five times less than at present, with the resulting massive sediments having "nonglacial" characteristics despite the presence of glacial ice in the drainage basin. A planktonic diatom flora suggests that summer lake ice cover was minimal at this time. A climatic deterioration at about 4500 BP marks the onset of the Neoglacial, recorded by a shift in the diatom assemblage to species characteristic of more shallow water environments. Retreat from Neoglacial moraines is recorded by clearly laminated sediments and increasing accumulation rates. In general, laminated sediments relate to periods of high sediment input associated with glacial retreat, whereas massive sediments relate to low sediment input in association with glacial stabilization or advance.

scholarly journals Influence of lake basin morphology on recent sedimentation rates based on the example of Lake Raduńskie Górne, N Poland

2016 ◽  
Vol 16 (3) ◽  
pp. 121-128 ◽  
Author(s):  
Karolina Czarnecka ◽  
Janusz Dworniczak
Keyword(s):  
Sediment Accumulation ◽  
Lake Basin ◽  
Sedimentation Rates ◽  
Accumulation Rates ◽  
Flat Bottom ◽  
Depositional Processes ◽  
Lake Bottom ◽  
Basin Morphology ◽  
Recent Sediments ◽  
Steep Slopes

Abstract The study relates to the use of the 210Pb method for determining sedimentation rates, sedimentation accumulation rates and identifying post-depositional processes. The analysis was based on seven cores of recent sediments collected from different parts of Lake Raduńskie Górne, which is a typical channel lake with diverse bottom morphology. We used alpha spectrometry to determine 210Pb activities in sediment samples and a CF:CS dating model to obtain mean sediment accumulation rates. The results show significant differences between coring sites with highest values in the deepest part of the lake and lowest within the shallow and flat bottom areas. The reason for such a large diversity is the lake basin morphology, e.g. steep slopes and complex configuration of the lake bottom, most probably responsible for the post-depositional sediment replacements.

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