Advective Mixing of Pore Waters and Ecology of Sandy Sediments of the Ocean Shelf

2003 ◽  
Vol 29 ◽  
pp. S1-S9 ◽  
Author(s):  
M. V. Propp
Keyword(s):  
Pore Waters ◽  
Advective Mixing ◽  
Sandy Sediments

scholarly journals Hydrochemistry of sediment pore water in the Bratsk reservoir (Baikal region, Russia)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
V. I. Poletaeva ◽  
E. N. Tirskikh ◽  
M. V. Pastukhov
Keyword(s):  
Pore Water ◽  
Ionic Composition ◽  
Water System ◽  
Water Reservoir ◽  
Environmental Parameters ◽  
Water Area ◽  
Pore Waters ◽  
Overlying Water ◽  
Major Ion ◽  
Bratsk Reservoir

AbstractThis study aimed to identify the factors responsible for the major ion composition of pore water from the bottom sediments of the Bratsk water reservoir, which is part of the largest freshwater Baikal-Angara water system. In the Bratsk reservoir, the overlying water was characterized as HCO3–Ca–Mg type with the mineralization ranging between 101.2 and 127.7 mg L−1 and pore water was characterized as HCO3–SO4–Ca, SO4–Cl–Ca–Mg and mixed water types, which had mineralization varying from 165.9 to 4608.1 mg L−1. The ionic composition of pore waters varied both along the sediment depth profile and across the water area. In pore water, the difference between the highest and lowest values was remarkably large: 5.1 times for K+, 13 times for Mg2+, 16 times for HCO3−, 20 times for Ca2+, 23 times for Na+, 80 times for SO42−, 105 times for Cl−. Such variability at different sites of the reservoir was due to the interrelation between major ion concentrations in the pore water and environmental parameters. The major factor responsible for pore water chemistry was the dissolution of sediment-forming material coming from various geochemical provinces. In the south part of the reservoir, Cl−, Na+ and SO42− concentrations may significantly increase in pore water due to the effect of subaqueous flow of highly mineralized groundwater.

Approaching daily life at Late Palaeolithic camps: The case of Lubrza 10, Western Poland

2020 ◽  
Vol 95 (2) ◽  
pp. 311-333
Author(s):  
Iwona Sobkowiak-Tabaka ◽  
Aleksandr Diachenko
Keyword(s):  
Daily Life ◽  
Site Formation ◽  
Site Formation Processes ◽  
The North ◽  
Locational Analysis ◽  
Research Procedure ◽  
Sandy Sediments ◽  
Integrative Social ◽  
Late Palaeolithic

AbstractThe aim of this paper is to develop a systematic approach to understanding daily life at Late Palaeolithic camps and identifying its impact on broader site formation processes. Late Palaeolithic contexts are often poorly preserved, especially those found in the sandy sediments of the North European Plain. However, taphonomic obstacles may be overcome through the introduction of spatial statistics into research procedures. We illustrate our approach using a case study of Federmesser and Swiderian campsites at the site of Lubrza 10, Western Poland. The locational analysis of hearths, features that constitute the most important integrative social foci of Palaeolithic camps, provides information on activity areas, seasonality and occupational duration. Additionally, we examine the function of spatially distinct artefact concentrations and their methods of aggregation. The presented research procedure enables us to trace the contribution of individuals to group behaviour, as well as specific individual activities at both camps.

scholarly journals Fluoranthene KDOC in sediment pore waters

Chemosphere ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 419-428 ◽  
Author(s):  
James M. Brannon ◽  
Judith C. Pennington ◽  
William M. Davis ◽  
Charolett Hayes
Keyword(s):  
Pore Waters

scholarly journals Seasonal Variations of Phosphorus Species in the Overlying and Pore Waters of the Tuohe River, China

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Qing Xu ◽  
Xiaoping Yu ◽  
Yafei Guo ◽  
Tianlong Deng ◽  
Yu-Wei Chen ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Yangtze River ◽  
Algal Bloom ◽  
Soluble Reactive Phosphorus ◽  
Pore Waters ◽  
Phosphorus Species ◽  
Dissolved Phosphorus ◽  
Vertical Distributions ◽  
Reactive Phosphorus ◽  
Main Factor

Overlying sediment and pore waters were collected in summer and winter at upstream (Jintang) and downstream (Neijiang) sites of the Tuohe River, which is one of the five largest tributaries of the Yangtze River in China. Phosphorus species, including soluble reactive phosphorus (SRP), soluble unreactive phosphorus (SUP), and total dissolved phosphorus (TDP), and some diagenetic constituents including dissolved Fe(II), Mn(II), and sulfide in overlying and pore waters, were measured systematically. The seasonal variations and vertical distributions of phosphorus species in overlying and pore waters at both sampling sites were obtained to elucidate some aspects of the transport and transformations of phosphorus. Based on the profiles of pore and overlying waters as well as the TDN/TDP data during an algal bloom in 2007, it was clearly demonstrated that phosphorus was the main factor limiting the phytoplankton growth in the Tuohe River.

Size spectra, body width and morphotypes of intertidal nematodes: an ecological interpretation

1999 ◽  
Vol 79 (6) ◽  
pp. 1007-1015 ◽  
Author(s):  
G. Tita ◽  
M. Vincx ◽  
G. Desrosiers
Keyword(s):  
Nematode Species ◽  
The Body ◽  
Influential Factor ◽  
Tidal Level ◽  
Body Width ◽  
Size Spectra ◽  
Lawrence Estuary ◽  
Quality Food ◽  
The Mean ◽  
Sandy Sediments

Nematode species from three intertidal assemblages (St Lawrence Estuary, Quebec, Canada) were studied in order to form an ecological interpretation of three allometric attributes: body width, size spectra, and morphotypes. The three assemblages were characterized by a very similar sediment grain median (Md) but different silt–clay proportions: A1 (upper-tidal level; Md=122 μm; silt=34.8%), A3 (mid-tidal level; Md=182 μm; silt=12.8%), and A5 (lower-tidal level; Md=122 μm; silt=6.8%). Silt–clay proportions were an influential factor in determining the mean nematode body width, used as a morphological discriminant between burrowing and interstitial organisms. A plot of the number of species vs the body width-classes showed two peaks: between 19.3 and 22.6 μm (interstitial), and between 32.0 and 45.5 μm (burrowers). As for the size spectra, in sandy sediments the mean nematode individual biomass was smaller than in muddy sediments. As a consequence, the estimated mean individual respiration rate was greater in muddy (A1=2.26 nl O2 h−1) than sandy sediments (A3=1.25 nl O2 h−1; A5=1.12 nl O2 h−1). In contrast, estimated metabolic ratios were lower in A1 (2.78 nl O2 h−1 μg−1 dry weight, DW) than in A3 (2.95 nl O2 h−1 μg−1 DW) and A5 (3.01 nl O2 h−1 μg−1 DW) suggesting different productivity and/or physiological adaptations to different lifestyles (burrowing vs interstitial) between species inhabiting muddy or sandy sediments. Morphotypes (body width/body length ratio=w/l ratio) were found to be associated with feeding groups. Small w/l ratios were typical of microvores, while greater ratios were typical of epigrowth feeders and predators. Ciliate-feeders, deposit-feeders and facultative predators had intermediate ratios. A morphotype food-related hypothesis is proposed: the species morphotype reflects the quality of exploited food; a small w/l ratio (i.e. long gut) would favour digestive efficiency and would be an adaptation to low quality food (microvores); inversely, a greater w/l ratio (i.e. short gut) would be an adaptation to high quality food (epigrowth-feeders and predators).

Dissolution and recrystallization in modern shelf carbonates: evidence from pore water and solid phase chemistry

1993 ◽  
Vol 344 (1670) ◽  
pp. 27-36 ◽  
Keyword(s):  
Organic Matter ◽  
Pore Water ◽  
Solid Phase ◽  
Chemical Exchange ◽  
Isotope Composition ◽  
Geochemical Data ◽  
Carbonate Sediments ◽  
Pore Waters ◽  
Carbonate Minerals ◽  
Carbonate Production

We present an overview of geochemical data from pore waters and solid phases that clarify earliest diagenetic processes affecting modern, shallow marine carbonate sediments. Acids produced by organic matter decomposition react rapidly with metastable carbonate minerals in pore waters to produce extensive syndepositional dissolution and recrystallization. Stoichiometric relations among pore water solutes suggest that dissolution is related to oxidation of H 2 S which can accumulate in these low-Fe sediments. Sulphide oxidation likely occurs by enhanced diffusion of O 2 mediated by sulphide-oxidizing bacteria which colonize oxic/anoxic interfaces invaginating these intensely bioturbated sediments. Buffering of pore water stable isotopic compositions towards values of bulk sediment and rapid 45 Ca exchange rates during sediment incubations demonstrate that carbonate recrystallization is a significant process. Comparison of average biogenic carbonate production rates with estimated rates of dissolution and recrystallization suggests that over half the gross production is dissolved and/or recrystallized. Thus isotopic and elemental composition of carbonate minerals can experience significant alteration during earliest burial driven by chemical exchange among carbonate minerals and decomposing organic matter. Temporal shifts in palaeo-ocean carbon isotope composition inferred from bulk-rocks may be seriously compromised by facies-dependent differences in dissolution and recrystallization rates.

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