Unusualcarbonaceousmatter,termedherechiemite,composedofmorethan90%CfromtheAlpineForelandatLakeChiemseeinBavaria,southeasternGermanyhasbeeninvestigatedusingopticalandatomicforcemicroscopy,X-rayfluorescencespectroscopy,scanningandtransmissionelectronmicroscopy,high-resolutionRamanspectroscopy,X-raydiffractionanddifferentialthermalanalysis,aswellasbyδ13Cand14Cradiocarbonisotopicdataanalysis.Inthepumice-likefragments,poorlyorderedcarbonmatterco-existswithhigh-orderingmonocrystallineα-carbyne,andcontainssubmicrometer-sizedinclusionsofcomplexcomposition.Diamondandcarbyneaddtothepeculiarmixofmatter.TherequiredveryhightemperaturesandpressuresforcarbyneformationpointtoashockeventprobablyfromtherecentlyproposedHoloceneChiemgaumeteoriteimpact.Thecarbonmaterialissuggestedtohavelargelyformedfromheavilyshockedcoal,vegetationlikewood,andpeatfromtheimpacttargetarea.Thecarbonization/coalificationhighPTprocessmaybeattributedtoastrongshockthatinstantaneouslycausedthecompleteevaporationandlossofvolatilematterandwater,whichneverthelesspreservedtheoriginalcellularstructureseenfossilizedinmanyfragments.Relativelyfreshwoodencapsulatedinthepurportedstronglyshockedmatterpointtoquenchedcarbonmeltcomponentspossiblyimportantforthediscussionofsurvivaloforganicmatterinmeteoriteimpacts,implyinganastrobiologicalrelationship.
