云南景谷盆地晚第三纪地层

LATE TERTIARY FORMATION IN JINGGU BASIN IN YUNNAN PROVINCE

景谷盆地位于滇西准地槽兰坪思茅中、新生代坳陷中、为一北北东向的晚第三纪地堑型断陷-坳陷盆地。上第三系自下而上划分为中新统三号沟组、回环组,上新统大红猫村组。并建立了五个孢粉组合,即单缝孢类优势组合、松柏类花粉优势组合、棒面单缝孢-枫香粉属组合、梣粉属-麻黄粉属-菊粉属组合及松科花粉组合。三个介形类化石组合,Cyprinotus-potamocypris组合、Herpetocyprella-Metacypris组合、LeucoCythere-Ilyocypris组合。古植物主要分布于三号沟组中段,称景谷植物群。

Jinggu Basin is a Mesozoic and Cenozoic depression in a parageosyncline located in Lanping and Simao areas in western Yunnan Province. It is a NNE oriented graben typefault-depression and depression basin. Neogene in the basin is divided into Shanhaogou andHuihuan Formations of Miocene and Dahongmaochun Formation of Pliocene in an as-cending order. Five spore-pollen assemblages have been recognized i.e. Monoletes-promi-nent assemblage, Coniferpollen assemblage, Clavato sporis-Liquidambarpollenites assem-blage Fraxinoipollenites-EphedripitesComposite assemblage and Pinaceae assemblage. Threeostracoda assemblages are also established i.e. Cyprinotus-Potamocypris assemblage,Herpetocyprella-Metacypris assemblage, and Leucocythere-Ilyocypris assemblage.Palaeobotany fossils called Jinggu flora are mainly yielded from the middle member ofShanhaogou Formation.