摘要
中国白垩纪大陆科学钻探松科1井南孔连续取泉四段至泉三段顶岩心,心长132.07m,岩心收获率为100.00%。松科1井南孔泉头组岩心的精细描述,揭示其岩性-岩相-旋回地层的序列及其过程。松科1井南孔泉头组取心段识别出9种基本岩石类型,相类型主要有曲流河、浅湖和三角洲前缘3种亚相,以及点砂坝、天然堤、决口扇、决口水道、河漫滩、河漫湖、河口砂坝、水下分流河道间、湖相静水泥质沉积和浊流沉积等10种沉积微相。相应井段可识别出2类8种米级旋回(六级旋回),整个井段由76个米级旋回构成,叠加成25个五级旋回、8个四级旋回和2个三级旋回。泉三、四段厘米级刻画的陆相红层为全球白垩纪富氧事件研究提供了可能的立典剖面。泉头组三、四段发育的在盆地内广泛分布的储层砂岩是大规模坳陷形成前的必然沉积产物,这一时期是松辽盆地由断陷向坳陷转化的阶段,也是大规模坳陷的初始阶段。
The Quantou Formation recovered by CCSD-SK-Ⅰs borehole (China Cretaceous Continental Scientific Drilling-SongkeⅠ-the south borehole) is 132.07 m long and 100% of cores recovery. The sequence and process of lithology-lithofacies and cyclic stratigraphy revealed by detailed core description. Nine rock types and three kinds of sedimentary facies including meandering river,shallow lake and delta front were recognized from the drilling core,there are ten sedimentary microfacies which are point bar,natural levee,crevasse splay,crevasse channel,floodplain,flood lake,subaqueous mouth bar,subaqueous inter distributary bay,mudstone of still water and turbidite. The Quantou Formation represents seventy-six meter-scale cycles (sixth-order cycle),twenty-five fifth-order cycles,eight forth-order cycles and two third-order cycles. Meticulously depicted(centimeter Level) continental red beds of the third and the fourth members of Quantou Formation will be a potential formulation profile for the studies on Cretaceous global oxygen-enriched events. The reservoir sandstones of the third and the fourth members were developed basinwide as an inevitable product before the Songliao Basin was depressed or sagged with a large scale. The period of the third and the fourth members of Quantou Formation was a stage between developments of the fault basin and the sag basin with a large scale.