摘要
中国白垩纪大陆科学钻探松科1井连续钻取嫩江组一、二段岩心长295.53m,岩心收获率为97.45%,是迄今获取的最连续完整的沉积记录。文章对此进行了厘米级沉积地质描述(分层厚度2～5cm)。嫩江组一、二段沉积时期与晚三冬—早坎潘期对应。通过对松科1井嫩江组一、二段岩心的精细描述,揭示其岩性-岩相-旋回的沉积序列及其过程。嫩江组一、二段共识别出12种岩石类型,为半深湖-深湖亚相的白云岩沉积、泥灰岩沉积、灰质泥岩沉积、油页岩沉积、浊流沉积、深湖静水泥和火山灰沉积等7种沉积微相。在岩相序列上识别出5种共213个米级旋回(六级旋回)、54个五级旋回、12个四级旋回和2个三级旋回。连续的组段厘米级刻画为高精度沉积过程研究提供了可能,嫩江组一、二段全井段取心对松辽盆地缺氧事件、烃源岩及湖海沟通事件的研究具有重要意义。该文的精细描述资料为今后相关的深入研究提供了迄今最精准的基本地质素材。
China Cretaceous Continental Scientific Drilling （CCSD） in the Songliao Basin, called SKI project, collected 295.53 m of the lower members 1＆2 of Nenjiang Formation which correspond to the late Santonian to early Campanian. The borehole got a highly continuous core section with recovery of 97. 45%, that is the most complete and precise sedimentary records up to now in the basin. Thicknesses of the description can be as thin as 2 - 5 crn for the interbedding sequences. We described the sedimentary sequence, lithology, lithofacies and cyclic stratigraphy at the drilling spot in cm-scale. Twelve litho-types were recognized in the section. Sedimentary facies are pre- dominantly lacustrine that can be subdivided into seven microfacies including dolomite, marl, argillaceous limestone, oil shale, turbidite, deep lake mudstone and volcanic ash microfacies. The whole sequence is composed of 213 meter- scale cycles （sixth-order cycle）, 54 fifth-order cycles, 12 fourth-order cycles and 2 third-order cycles. Centimeterscale depiction of the section revealed some previously unknown horizons such as special kind of mudstone, dolomite and volcanic ash of the formation. The new found evidences are very important for us to interpret basin evolution fea- tures such as lake anoxic, source rock development and the potential linkage between lake and adjacent sea. That is to say, the scientific drilling provides us with powerful insight into the basin. Researchers who are interested in the basin can do their reasonable analysis of the basin on the basis of the precise original materials of the paper.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2011年第6期195-217,共23页
Earth Science Frontiers
基金
国家重点基础研究发展计划"973"项目(2012CB822002)
关键词
松辽盆地
松科1井
嫩江组一
二段
沉积相
沉积序列
旋回地层
Songliao Basin
SK1
the first and second members of Nenjiang Formation
sedimentary facies
sedimentary sequence
cyclostratigraphy
