泰国东南部Rayong省Klaeng地区的中?晚泥盆世放射虫

TectonicsubdivisionofmainlandThailandhasbeendiscussedbymeansofPaleozoicandMesozoicstratigraphy,micropaleontologyrepresentedbyfo-raminiferalandradiolarianbiostratigraphyandpaleo-biogeography,tectonicsettingsofgranitoids,andul-tramaficrocksthataredistinctiveofsuturelines.Re-cently,Ueno(2002)andUenoandCharoentitilat(2011)proposedanewtectonicschemeofmainlandThailandanddivideditintothreegeotectonicunits:theSibu-masuBlock,SukhothaiZone,andIndochinaBlockfromwesttoeast,whichareseparatedbytheMaeYuanFault,theChiangRaiTectonicLine,andtheNan–UttaraditSuture,respectively.InNorthernThai-land,moreover,thepeculiarInthanonZoneisrecog-nizedintheeasternpartoftheSibumasuBlock,wherePaleo-Tethyanoceanicrocksarewidelydistributedastectonicslices.ThesegeotectonicsubdivisionsinNorthernThailandarerelativelyclear.However,thetectonicsubdivisionsofCentralandSoutheastThai-landhavenotbeenwelldocumentedandarestillcon-troversialbecausethereisshortofinformationaboutbasementrocksinthoseareas.Inthiscircumstance,wehaveexaminedPaleozoictoMesozoicstratigraphy,lithology,andradiolarianagesofsiliceousrocksdis-tributedinSoutheastThailandtoclarifythegeotec-tonicbelongingsofthisareaandthesouthernexten-sionsofgeotectonicunitsconsistingofNorthernThailand.Inthecourseofthisresearch,wecouldob-tainMiddletoLateDevonianradiolariansfromwell-beddedsiliceousrocksdistributedinsouthwestofKlaeng,RayongProvince.Inthisstudy,wereportlithologyandageoftheradiolaria-bearingrocksanddiscusstheirstratigraphyandgeologicalcorrelationnearbytheKlaengregion.