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(1)olderthantherockinwhichwefindittodaylifitislocatedinasecond-
arydeposit,whichisthecasewithBaltic,UkrainianorBitterfeldamber;
(2)isochronous(=ofthesameage)liftheamberwasfoundinaprimary
deposit,whichisthecasewith,forinstance,valchovite,afossilresinfoundin
Moravia;
(3)youngerthantherocklifwecandetermineonlytheageofthesediment
orrockdepositedundertheamber-bearinglayers.
Inthecaseofamberwhichwasredepositedfromitsprimaryorsecondary
depositontootherdeposits,evendeterminingtherelativeagerequiresbothin-
depthgeologicalresearchandananalysisofthepropertiesoftheresin.
Forinstance,wecanestablishthattherelativeageofBalticamberisatleast
theLateEocene,asitisfoundinasecondarydeposit,inthelayersofblue
earth,datedtotheUpperEocene.TheabsoluteageofUpperEocenesediments
canbefoundonageologicaltimescaleestablishedin2004bytheInternational
CommissiononStratigraphy.TheLateEocene(Priabonian)lastedfrom37.2to
33.9Maago.
Radiocarbondating,whichisbasedonthecontentratioofthe12Cand14C
carbonisotopeandisusedtodeterminetheageofmaterialsoforganicorigin,
canonlybeusedforagesupto60,000years,whichmakesitapplicableonlyto
somesubfossilresins.
Inrecentyears,therehavebeenattemptstodeterminetheageoffossil
resinsbymeansofthermalanalysis:Thermogravimetry(TG)andDifferential
Thermogravimetry(DTG).Derivatographsmeasurechangesinmass(lossesor
gains)whichoccurwithtemperatureincrease(TG)andtherateofchangesin
massalsodependentonthetemperaturechange(DTG).Theresultsobtainedus-
ingthesemethods,togetherwithothertests,canbehelpfulinagedetermination
byinterpretingtheresins,degreeofKmaturity
.”Atthemoment,however,itwould
bedifficulttoquoteadefinitivemethod,althoughtheCretaceousfossilresinsof
Francehavedisplayedtheexpectedchangesintheseanalyses.
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