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西峡盆地上白垩统寺沟组岩性以紫红色薄层粉砂质泥岩、灰黄—灰绿色厚层状粉砂岩、细砂岩为主,夹灰黄、灰白色厚层状含砾砂岩及中粗砂岩。本次工作发现遗迹化石11属19种:包括Archaeonassaisp.,Arenicolites isp.,Cylindricumisp.,Beaconites antarcticus,B.capronus,B.coronus,Gastruichnus xixiaensis,Naktodemasis isp.,Palaeophycus tubularis,P.heberti,P.sulcatus,P.striatus,Planolites beverleyensis,Planolitesisp.,Scoyenia gracilis,Skolithos verticalis,Skolithos isp,Taenidium irregularis,T.serpentinum和似逃逸迹。根据遗迹化石的产状及其围岩的沉积特征,建立了Beaconites-Palaeophycus遗迹组合和Taenidium-Scoyenia遗迹组合,分别代表了曲流河和浅水湖泊(河漫湖泊)沉积环境中遗迹化石的组成特征。基于岩性特征、沉积构造和遗迹化石组成特征的综合分析,划分出五种沉积序列类型,揭示了寺沟组曲流河边滩、泛滥平原、洪流砂体与河漫湖泊在沉积过程中的变化和相应的遗迹群落变化特征。结合寺沟组中遗迹化石分布及组合特征,Beaconites-Palaeophycus遗迹组合和Taenidium-Scoyenia遗迹组合可归属于Scoyenia遗迹相。
The lithology of the Upper Cretaceous Shigou Formation in the Xixia Basin is mainly composed of purple-red thin silty mudstone, greyish-gray-greenish thick layered siltstone and fine sandstone with thick grained yellowish-gray sandstone and middle gravel sandstone Coarse sandstone. This work found that there are 19 species of 11 genera in the relics, including Archaeonassaisp., Arenicolites isp., Cylindricumisp., Beaconites antarcticus, B.capronus, B.coronus, Gastruichnus xixiaensis, Naktodemasisisp., Palaeophycus tubularis, P.heberti, P..sulcatus , P.striatus, Planolites beverleyensis, Planolitesisp., Scoyenia gracilis, Skolithos verticalis, Skolithos isp, Taenidium irregularis, T. serpentinum, and escaped traces. According to the occurrence of the trace fossils and the sedimentary characteristics of the surrounding rocks, the Beaconites-Palaeophycus relic assemblage and the Taenidium-Scoyenia relic assemblage are established, which respectively represent the compositional features of the trace fossils in the sedimentary environment of meandering rivers and shallow lakes (He Man Lake). Based on the comprehensive analysis of the characteristics of lithology, sedimentary structure and trace fossils, five types of sedimentary sequence are divided and the variation of meandering rivers, floodplains, flood sand bodies and flood plain lakes in the Shitou Formation are revealed And the corresponding relic community change characteristics. Combined with the distribution of fossil remains and their assemblage in the Tegilogou Formation, the combination of Beaconites-Palaeophycus relics and Taenidium-Scoyenia relics can be attributed to the Scoyenia relics.