松科1井南孔白垩系姚家组沉积序列精细描述：岩石地层、沉积相与旋回地层

Description of Cretaceous sedimentary sequence of the Yaojia Formation recovered by CCSD-SK-Ⅰs borehole in Songliao Basin:Lithostratigraphy,sedimentary facies and cyclic stratigraphy

中国白垩纪大陆科学钻探松科1井南孔连续取姚家组岩心长157.67m,岩心收获率为99.96%。上白垩统姚家组对应着三冬阶和坎潘阶下部。松科1井南孔姚家组岩心的精细描述,揭示其岩性-岩相-旋回的沉积序列及其过程。姚家组中可识别基本岩石类型11种,相类型为浅湖、半深湖和三角洲前缘3种亚相,白云岩沉积、泥质灰岩沉积、浅湖和深湖浊流沉积、河口坝、远砂坝、席状砂、分流间湾、水下滑塌沉积、浅湖和深湖静水泥沉积11种沉积微相。姚家组可识别的米级旋回(六级旋回)有8种类型,可划分出151个米级旋回。这些米级旋回叠加成45个五级旋回、9个四级旋回和3个三级旋回。完整组段厘米级刻画为高精度沉积过程研究提供了可能。姚家组红层厚度占姚家组总厚度的43%,作为该时期已被揭示的全球为数不多的陆相红层之一,厘米级刻画的姚家组大套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。

The Yaojia Formation recovered by CCSD-SK-Ⅰs borehole （China Cretaceous Continental Scientific Drilling-Songke Ⅰ -the south borehole） is 157.67 m long and 99.96% of cores recovery. The age of the Formation corresponds to a range from the Santonian to the early Campanian. The sequences and processes of lithology-lithofacies and cyclic stratigraphy were revealed by a detailed core description. Eleven rock types and three kinds of sedimentary subfacies including shallow lake, deep lake and delta front were recognized from the drilling core. There are eleven sedimentary microfacieses including dolostone, argillaceous limestone, shallow lake turbidite, deep lake turbidite, subaqueous mouth bar, distal bar, sheet sandstone, subaqueous distributary bay, slump deposits, shallow lake mudstone and deep lake mudstone. The Yaojia Formation represents one hundred and fifty-one meter-scale cycles （sixth-order cycle）, forty-five fifth-order cycles, nine fourth-order cycles and three third-order cycles. Meticulous depiction （centimeter level） of the whole Formation provides an approach to study its sedimentary process with high precision. The red beds with thickness of 43% in the Yaojia Formation, being one of fewer continental red beds depicted meticulously in the world, will become a standard potential formulation section for the studies of Cretaceous global oxygen-enriched events.