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斋桑盆地自晚白垩世以来即为淡水湖泊环境 ,其始新世至中新世湖相及湖边缘相沉积物产有丰富的轮藻化石。文中建立三个轮藻化石组合 :(1) H arrisichara mitella- Peckisphaera zajsanica组合 (中始新世早期 ) ;(2 ) L ych-nothamnusformosus- Peckichara组合 (中始新世晚期—渐新世早期 ) ;(3) Gyrogona aralica- Sphaerochara clearus组合 (中—晚渐新世 )。斋桑盆地轮藻化石出现的最高层位为下中新统且化石稀少 ,推测系盆地环境日益干旱所致。
The Zaisang Basin is a freshwater lake environment since the Late Cretaceous. Its Eclogites and Lake Edge sediments are rich in Chara fossils from Eocene to Miocene. In the paper, three charachamorphic fossil assemblages were established: (1) Harisristemlaepeella-Peckisphaera zajsanica assemblage (middle Eocene); (2) L ych-nothamnusformosus-Peckichara assemblages (middle-late Pleistocene-Oligocene); (3) Gyrogona aralica-Sphaerochara clearus assemblage (mid-Oligocene). In the Zaisang Basin, the highest level of charophytes occurred in the Lower Miocene with few fossils, which is presumed to be caused by the increasingly dry environment in the basin.