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001-es BibID:	BIBFORM080901
Első szerző:	Braun Mihály (vegyész, analitikus)
Cím:	Using linear discriminant analysis (LDA) of bulk lake sediment geochemical data to reconstruct lateglacial climate changes in the South Carpathian Mountains / M. Braun, K. Hubay, E. Magyari, D. Veres, I. Papp, M. Bálint
Dátum:	2013
ISSN:	1040-6182
Megjegyzések:	A multi-proxy approach is widely used for reconstructing climatic change in alpine lake sediments. This study applied bulk sediment geochemistry to reconstruct lateglacial and early Holocene climatic change in a glacial lake (Lake Brazi, 1740 m a.s.l.) in the Retezat Mts. (South Carpathians, Romania). The lowermost 1 m part of a 4.9-m long sediment core, covering the period between 9950 and 15,750 cal BP, was used for high resolution bulk analysis of major elements (Al2O3, SiO2, TiO2, CaO, MgO, K2O, Na2O, Fe2O3, MnO, SO3). Linear discriminant analysis (LDA) was used to compare a priori classified main chemical groups. Subsamples from the core were priory ordered to "warm" and "cold" groups respectively, according to their age and evidence of cold and warm events in the record, as suggested by proxy correlation with the lateglacial event stratigraphy of North Greenland Ice Core Project (NGRIP). The discriminant function was calculated using concentrations of Al2O3, TiO2, CaO, MgO, K2O, Na2O, Fe2O3, and MnO after log ratio transformation. Loss-on-ignition, silicon and sulphur concentrations were not used for the discriminant analysis, but regarded as comparison proxies for checking up the validity of outputs. Sediments deposited during "cold" and "warm" events were separated significantly by the LDA function; 85.1% of the originally grouped cases were correctly classified under the LDA analysis. The calculated discriminant scores indicated four "cold" and four "warm" events. Sediments ordered into the "warm" group contained larger amounts of organic matter and sulphur, while sediment samples of the "cold" group were characterized by the overall predominance of major oxides bound into inorganic silicates. The discriminant scores showed strong correlation with the NGRIP ?18O data (r = 0.8135) and with the pollen percentage sum of trees and shrubs (r = 0.9460). Loss-on-ignition showed a somehow weaker, but still conclusive linear relationship with the discriminant scores (r = 0.7505). Discriminant analyses of bulk sediment major oxide chemical data may be a useful tool to identify the impact of climatic events upon the nature and composition of materials delivered to a lake basin.
Tárgyszavak:	Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Quaternary International. - 293 (2013), p. 114-122. -
További szerzők:	Hubay Katalin (1985-) (biológus, környezetkutató) Magyari Enikő (1973-) (biológus) Veres Dániel Papp István (1980-) (vegyész) Bálint Miklós
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001-es BibID:	BIBFORM116214
035-os BibID:	(Scopus)85163811294 (WOS)001022818100013
Első szerző:	Simon, Marcel Pierre
Cím:	Dissent in the sediment? Lake sediments as archives of short- and long-range impact of anthropogenic activities in northeastern Germany / Marcel Pierre Simon, Marlene Schatz, Leonard Böhm, István Papp, Hans-Peter Grossart, Thorbjørn Joest Andersen, Miklós Bálint, Rolf-Alexander Düring
Dátum:	2023
ISSN:	0944-1344 1614-7499
Megjegyzések:	The suitability of lake sediment cores to reconstruct past inputs, regional pollution, and usage patterns of pesticides has been shown previously. Until now, no such data exist for lakes in eastern Germany. Therefore, 10 sediment cores (length 1 m) of 10 lakes in eastern Germany, the territory of the former German Democratic Republic (GDR), were collected and cut into 5-10-mm layers. In each layer, concentrations of trace elements (TEs) As, Cd, Cr, Cu, Ni, Pb, S, and Zn, as well as of organochlorine pesticides (OCPs), i.e., dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), were analyzed. A miniaturized solid-liquid extraction technique in conjunction with headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was used for the latter. The progression of TE concentrations over time is uniform. It follows a trans-regional pattern and is indicative of activity and policy making in West Germany before 1990 instead of those in the GDR. Of OCPs, only transformation products of DDT were found. Congener ratios indicate a mainly aerial input. In the lakes' profiles, several regional features and responses to national policies and measures are visible. Dichlorodiphenyldichloroethane (DDD) concentrations reflect the history of DDT use in the GDR. Lake sediments proved to be suitable to archive short- and long-range impacts of anthropogenic activity. Our data can be used to complement and validate other forms of environmental pollution long-term monitoring and to check for the efficiency of pollution countermeasures in the past.
Tárgyszavak:	Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Chronology Dichlorodiphenyltrichloroethane (DDT) Landscape development Mecklenburg-Brandenburg lake district Organochlorine pesticide (OCP) Sediment core Trace elements Transformation products
Megjelenés:	Environmental Science And Pollution Research. - 30 : 36 (2023), p. 85867-85888. -
További szerzők:	Schatz, Marlene Böhm, Leonard Papp István (1980-) (vegyész) Grossart, Hans-Peter Andersen, Thorbjrn Joest Bálint Miklós Düring, Rolf-Alexander
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