An anomalous atmospheric dust deposition event over Central Europe, 24 March 2007, and fingerprinting of the SE Ukrainian source

Bulletin of geosciences

Å imandl P¹  Schwarz J¹  Rohovec J¹  Koptíková L¹  Strnad L¹  Melichar R¹  Jankovská V¹  Adamovič J¹  Langrová A¹  Šálek M¹  Hladil J¹  Kociánová M¹  Lisá L¹  Smolík J¹  Böhmová V¹ 

关键词: dust;    atmospheric deposition event;    sedimentology;    rheology;    grain-size modality;    pattern formation;    geochemistry;    lead isotopes;    pollen and spores;    eolian flux;    climate change;    Czech Republic;    Ukraine;    Europe;    Recent/Holocene;   

DOI  :  

来源: Czech Geological Survey

【 摘 要 】

AnanomalouseventofUkrainianquartz-dominateddustdepositedintheCzechRepublicandadjacentcountrieson24March2007wasstudiedwithspecialemphasisonsedimentology,mineralogyandgeochemistry.Thedustdepositioncombinedatypicaleoliandepositionalmodewithonemediatedbydirtyrainordrizzle.Themainstageofsedimentdepositionwasshort(severaltensofminutes)andsynchronouswithrapidlyincreasedconcentrationofparticlessmallerthan10micro;mintheatmosphereaboveground.Thepolydisperseandmultimodalsedimentconsistedpredominantlyofangulartosubroundedquartzparticles,ofwhich80-90wt.%weresiltsized(4-63micro;m).Asmallamountofsandgrainsupto0.5mminsizewasregularlyobserved(?10wt.%)andwashigherthanthatofparticlessmallerthan4micro;m.Thisrelativelycoarsematerialwastransportedbyatmosphericflowsoverdistancesof1400to2000km.Thedepositedsiltfilmwasfenestrallyarrangedandshowedvariousreticulateandpatchypatternsofseveralsizes.Theintensityofdepositioninthemaindepositionareascorrespondedto2.3g/m2ofparticulatesolidsonaverage.Theinterpreteddepositionalprocessesarebasedondirectobservationanddustmicrophysics.Besidesthepreferentiallyentrainedanddeliveredquartz,thesedimentcontainsalsoperthiticfeldspar,chloriteandchloritoids,andnotablylowamountsofmica,claymineralsandcarbonate.Theelementcontentdoesnotcontradictthesupposedsourcebasedonmeteorologicalobservations,i.e.,fromsurfaceargillaceousandsandysoilseastofKherson,Ukraine.Particularlyminorandtraceelementdistributionsarealmostidenticalandshowanearlyperfectmatch,closelysimilartothoseofstandardsfortheuppercrust(notsediments).TotalFeconcentrationsinthesedimentareabout2-3wt.%,i.e.,slightlylessthanthosefortheuppercontinentalcrustonaverage,yetwithalargeproportionofironstillboundinmineralinclusionsinquartzandsilicates.SmoothREEpatternscorrespondtothemostcommonmulti-cycleeolianmaterialandaretypicalfortheassumedsourcearea.Leadisotopesignaturescombineanaturallithicimprintandanthropogeniccontaminationbypetrolcombustion,therebygivingasomewhatdifferenttrendcomparedtoAfricansources.Palynologicalanalysisenabledtrackingofthetrajectoryofthedust-flowbutalsoidentifiedtypicalmarkers,suchasragweedpollen,fromthesourcearea.

【 授权许可】

Unknown