Late Palaeozoic palynomorph assemblages from the Karoo Supergroup and their potential for biostratigraphic correlation, Kalahari Karoo Basin, Botswana

摘要

LateCarbonifeoustoPermiancoresamplesfromtwoboreholesections,STRAT1andCKP6,thatpenetratetheglacialtopostglacialandcoal-bearingLowerKaroosequence,KalahariKarooBasin,Botswana,containwellpreservedpollenandsporepalynomorphs.Thepalynomorphassemblagescomprise165speciesofsporesandpollen,andfewacritarchsandchlorophyceanalgae.Thispaperpresentsalocalbiozonationofthreesucceedingassemblagezones,recognisableineachboreholesection.Theassemblagezonesarenamed:theHamiapollenitesbullaeformisBiozone,theCyclogranisporitesgondwanensisBiozoneandthePlatysaccuspapilionis-StriatopodocarpitesfususBiozone,inascendingorderofstratigraphy.AssemblagesarecomparedandcorrelatedwithassemblagesdescribedfromotherGondwanaareasofAfrica,Australia,Arabia,SouthAmericaandAntarctica.AgeneralanalysisoftaxafromtheKalahariKarooBasinindicatesadistinctsimilaritywithassemblagesfromtheParan??BasinofSouthAmerica.TheHamiapollenitesbullaeformisBiozoneiscomparablewiththeVittatinacostabilisIntervalZoneoftheParan??Basin.AssemblagesfromtheCyclogranisporitesgondwanensisandthePlatysaccuspapilionis-StriatopodocarpitesfususzonesarecomparablewiththeLueckisporitesvirkkiaeIntervalZone.AgedeterminationfortheassemblagesintheKalahariKarooBasinisinferredfromcomparisonwithsimilarassemblagesfrompreviousGondwanastudies,andrangesfromtheLateCarboniferous(Kasimovian-Gzhelian)tolatestEarlyorpossiblyearliestMiddlePermian(LateCisulariantoEarlyGuadalupian).