SedimentaryEnvironmentandMineralizationMechanismofthe StromatoliticPhosphoriteintheEdiacaranDengyingFormation, Weng′anCountyofGuizhouProvince,China
Stromatolitic phosphorite in the Ediacaran Dengying Formation was initially discovered in Weng′an-Fuquan area of SouthwesternGuizhouProvince,Chinawherephosphateoresarewidelydistributed.Asanewphosphorousstratumofphosphorite,itis characterizeddominantlybytypicalstromatoliticstructures.ThephosphoriteofstromatoliteislocatedatthetopoftheEdiacaran DengyingFormationthatiscomposedoflenticularorganicreef(algalreefofstromatolite).Themajormineralcomponentsofthe stromatoliticphosphoritearephosphatesandcarbonates.Thewhitelaminatedbedsareenrichedinphosphatemineralswhilethedark laminatedbedshavelowercontentsofphosphatemineralsandcontainmainlycarbonateminerals.Analysisofthemineralogicaland geochemicalcharacteristicsindicatesthatstromatoliticphosphoriteintheEdiacaranDengyingFormationisalgalreefofstromatolite thatwasformedinasemi-restrictedsubtidalenvironment.Accordingly,itcouldbeinferredthatthephosphoriccolumnarstromatolitic reefswereformedbyenrichmentinandprecipitationofphosphorusfromtheseawaterwithrichphosphorusduetocomplexbiological orbio-chemicalactionsofalgae.Inaddition,theresultsshowthatthemineralizationofphosphaticmineralsoccurredmainlyatthe sediment-waterinterfaceinweaklyalkalineandsuboxicenvironmentwherealgaehadplayedasignificantrole.
ZHANG Wei, YANG Ruidong*, MAO Tie, REN Haili, GAO Junbo, CHEN Jiyan . SedimentaryEnvironmentandMineralizationMechanismofthe StromatoliticPhosphoriteintheEdiacaranDengyingFormation, Weng′anCountyofGuizhouProvince,China[J]. Geological Journal of China Universities, 2015 , 21(2) : 186 . DOI: 10.16108/j.issn1006-7493.2
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