本文系统描述了产自泽当金鲁乡鲁巴垂附近5块硅质岩样品中保存较好的放射虫化石,共20属26种(含未定种),包括BecustriangulocentrumDumitrica,Cecropsseptemporatus(Parona),Cryptamphorellaconara(Fore—man),Dicerosaturnalisdicranacanthos(Squinab01),Eucyrtidiellumpyramis(Aita),Hiscocapsaverbeeki(Tan),H.uterculus(Parona),HolocryptocaniumbarbuiDumitrica,Praeconosphaerasphaeroconus(Rust)和Tethysettaboesii(Parona)等重要分子。通过与西特提斯地区放射虫化石带的对比,可确定这些放射虫化石组合相当于UA—Zone13-UAZone22带,其时代为晚侏罗世提塘晚期-早白垩世阿普特期。有关雅鲁藏布江缝合带东段蛇绿岩体中的放射虫化石目前只有零星的报道,尚缺乏系统的研究。本文所发现的放射虫化石组合可为雅鲁藏布江缝合带东段泽当蛇绿岩体的时限提供重要的时代依据。
Moderate preserved 26 radiolarian species belonging to 20 genera collected from a cherty block and one radio- larite sample near the Lubachui village of Jinlu, Zedong Town, Southern Tibet, China were described systematically. They are mainly composed of Becus triangulocentrum Dumitrica, Cecrops septemporatus (Parona), Cryptamphorella conara (Foreman), Dicerosaturnalis dicranacanthos (Squinabol), Eucyrtidiellum pyrarnis (Aita), Hiscocapsa ver- beeki (Tan), H. uterculus (Parona) , Holocryptocanium barbui Dumitrica, Praeconosphaera sphaeroconus (Riast) and Tethysetta boesii (Parona). By compared with the radiolarian zones in West Tethys, these Tibetan radiolarian as- semblages (zones) can be correlated with UAZone 13, UAZone 17 and UAZone 22 respectively, which indicated the chert blockis from upper Jurassic (Tithonian) to lower Cretaceous (Aptian). Few research works on the radiolarian biostratigraphy has been previously clone in this region. The radiolarians described in this paper will provide an impor- tant evidence for the time constrain on the ophiolite in Zedong, Southern Tibet.