论文部分内容阅读
现生枝角类Cladacera属于节肢动物门,甲壳纲,鳃足亚纲,通称溞Daphnia。在渤海湾盆地下第三系沙河街组地层中陆续见到枝角类化石,在地层对比及沉积相研究中起到的一定作用。 (一)沙河街组三段 东濮凹陷中部和北部,是盐类沉积的主要发育地区,沙河街组三段中下部由盐岩层、盐膏岩层夹灰色泥岩、薄层油页岩、灰质页岩组成的盐韵律段。化石有Huabeinia obscura,H.costatispinata,并有一定数量的钙质超微化石,如Reticulofenestra sp.,Coronocyclus sp.,
Cladacera now belongs Cladacera arthropod door, crustacean, gill foot subclass, commonly known as 溞 Daphnia. Dendrocalamus fossils are successively seen in the strata of the Lower Tertiary Shahejie Formation in the Bohai Bay Basin and play a part in the stratigraphic correlation and sedimentary facies study. (1) The middle and lower parts of the third member of Shahejie Formation are mainly mudstone, saline shale, limestone shale, limestone shale Rock salt composition of the rhythm section. Fossils Huabeinia obscura, H.costatispinata, and a certain number of calcareous fossils, such as Reticulofenestra sp., Coronocyclus sp.,