@article{f8f7f66b-f0eb-4689-93e5-174a7b0b9f4a,
author = {Ryszard K.  Borówka, Julita Tomkowiak, Daniel Okupny, Jacek  Forysiak},
title = {Chemical composition of biogenic sediments from the Rawka river valley (Kopanicha peatland, Łowicz-Błonie Plain)},
journal = {Folia Quaternaria},
volume = {2015},
number = {Vol. 83 (2015)},
year = {2015},
issn = {0015-573X},
pages = {25-44},keywords = {},
abstract = {Kopanicha peatland is located in western part of the Rawka river valley, near Skierniewice. In order to reconstruct the main stages of sedimentation of organic deposits, taken from the central part of the Kopanicha peatlands, used stratigraphic variability of concentration marked lithogeochemistry elements (organic matter, mineral matter, macro- and microelements) and erosion index (Na+Mg+K/Ca), eutrophication index (Fe/Ca), type and rate of denudation in the catchment index (Na/K, Ca/Mg) and redox index (Cu/Zn, Fe/Mn).
Peat development in the oxbow lake complex occurred at the beginning of the Atlantic period, and peat growth lasted until the modern times, but with clear interruptions in the Atlantic and Subatlantic (Forysiak 2012).
As a result of the hierarchical cluster analysis seven geochemical zones (Kop1/I-VII ) were selected. These zones differ significantly of chemical composition. The main component of studied sediment is organic matter (84.6–95.5%), which indicates the relative changes in the primary of biological production in wetlands. The average content of the tested components have the low differentiation between all geochemical levels, constitute a record of stable environmental conditions (mainly hydrological and geomorphological). Sediments of geochemical level Kop-1/I are characterized by the high content of mineral matter and higher rates of mechanical denudation and erosion rate of the catchment. Geochemical levels Kop-1/II and Kop-1/III provide the record of sedentation autochtonous rock-forming matter of autogenic origin (increase content of organic matter to 95.5% and associated change of mechanical denudation and redox conditions (decrease of lithogenic elements and Fe/Mn ratio). Geochemical levels Kop1/IV represents the phase of alder swamp peat layer deposition in reduced conditions (increased Fe/Mn ratio to 80.8) and increased chemical denudation (Ca/Mg ratio ranges from 32.6 to 69.2). Geochemical level Kop-1/V records sedentation of autochtonous rock-forming matter of autogenic origin (organic matter ranges from 90.2% to 91.6%) and associated change of mechanical denudation (first increase catchment erosion indicator to 0.88 and then decrease to 0.78) and redox conditions (first increase conditions of oxidation-reduction indicator to 96.4 then decrease to 62.8). Their sedimentation took place both in stagnant ground waters, as well as during periodic floods. Geochemical level Kop-1/VI represents of peat layer, which sedentation occurred in periodic of drying bed. The content of organic matter decreased to about 90% and Fe/Mn ratio decreased to 39, indicates the change of reduced into oxidized conditions. Geochemical level Kop-1/VII is the record change type of sedentation of peat on muck, as is also indicated by abrupt decrease of organic matter (from 93.7 to 88.8%), decrease of Fe/Mn ratio (to 26.7) and increase in catchment erosion indicator (from 0.6 to 0.74).
The most important factors (distinguished on the basis of principal components analysis) that affect the chemical composition of sediments from the site Kopanicha are: sorption of organic deposits, oxygenation changes in sedimentary environment, which are mainly due to the flooding of the Rawka river},
doi = {10.1515/folquart -2015-0005},
url = {https://ejournals.eu/en/journal/folia-quaternaria/article/sklad-chemiczny-osadow-bagiennych-z-doliny-rawki-torfowisko-kopanicha-rownina-lowicko-blonska}
}