松辽盆地上白垩统陆相遗迹化石及其沉积环境

松辽盆地上白垩统中含有丰富的遗迹化石，通过对该盆地20余口取心井岩心的详细观察，发现了6大类动物遗迹化石15属20种。根据这些遗迹化石的分布规律，在松辽盆地上白垩统中划分出5种遗迹化石组合：（1）Scoyenia遗迹组合，主要成分有Scoyenia gracilis、Skolithos和Planolites，偶见停息迹化石，反映的是遭受周期性暴露的极浅水环境；（2）Skolithos遗迹组合，主要以Skolithos和Cylindricum十分发育为特征，分异度小，丰度高，反映的是高能动水环境。（3）Arenicolites遗迹组合，主要以Arenicolites和Polykladichnus大量发育为特征，还见有Skolithos、Planolites、Thalassinoides和逃逸迹等化石，分异度较高，反映了水流能量较低的浅水环境；（4）Planolites遗迹组合，以密集分布的Planolites十分发育为特征，分异度小，丰度高，见有少量指示缺氧环境的Chondrites化石，反映了水体较平静的还原环境；（5）Fuersichnus遗迹组合，主要由Fuersichnus、Glockeria、Gordia、Megagrapton和Planolites等遗迹分子构成，反映了相对平静的深水环境。

Continental trace fossils and their sedimentary environments of the Upper Cretaceous in Songliao Basin

Trace fossils are abundant in the Upper Cretaceous in the Songliao Basin.Based on the observation of cores of 20 wells,6 types of trace fossils including 15 genera and 20 species are identified in the basin.According to the distribution of these trace fossils in the Songliao Basin,5 ichnoassemblages are distinguished in the Upper Cretaceous as:(1) Scoyenia ichnoassemblage,which mainly includes Scoyenia gracilis,Skolithos,Planolites and Cubichnia,represents shallow water sedimentary environments with periodical exposure;(2)Skolithos ichnoassemblage,which is characterized by the abundance of Skolithos and Cylindricum with low diversity,reflects high energy environments;()Arenicolites ichnoassemblage,which is composed of Arenicolites,Polykladichnus,Skolithos,Planolites,Thalassinoides and Fugichnia with high diversity,represents shallow and low energy environments;(4)Planolites ichnoassemblage,which is dominated by rich Planolites and Chondrites with low diversity,indicates anoxic quiet water environments;(5)Fuersichnus ichnoassemblage,which contains Fuersichnus,Glockeria,Gordia,Megagrapton and Planolites,suggests deep and relatively quiet water environments.