层序地层学标准化理论在陆架坡折-陆坡区的应用——以珠江口盆地中中新世沉积层序为例

层序地层学标准化理论在陆架坡折-陆坡深水区的应用尚未成熟。截至目前，基于浅层高分辨率地震和露头资料对深水层序开展的研究大多聚焦于深水水道或盆底扇内部，而忽视了与上陆坡以及陆架体系的系统对比。将层序地层学标准化理论应用于珠江口盆地中中新世（13.8 Ma前后）的陆架坡折到陆坡区，通过三维地震资料的系统解释、属性提取、可视化和钻测井信息分析，建立了从陆架到陆坡区的统一层序地层格架。在此基础上，明确了珠江口盆地陆架坡折-陆坡深水区中中新世沉积层序具有海侵体系域和高位体系域厚度薄、强制海退体系域和低位体系域前积层厚度大，以及底积层（主要为深水扇）普遍发育于低位体系域的层序地层发育特征。深水区层序地层格架的建立应从陆架坡折区到深水区整体考虑，结合“源-汇”体系演化特征进行三维空间的系统对比，才能准确划分各个体系域，从而更好地认识陆架-陆坡-深水区的沉积耦合关系。

Application of standardized sequence stratigraphy theory in the shelf break-to-slope area: A case study of the Middle Miocene sedimentary sequence in the PRMB

The application of standardized sequence stratigraphy theory is yet to be improved in the shelf break-to-slope area in deep water. As of now, the researches on the sequence stratigraphic framework mostly focus on deep-water channels or interior basin floor fans (BFFs) based on the high-resolution seismic data of shallow layers and outcrop observation, while ignoring systematic correlation with the upper slope and shelf system. In this regard, the study sets up a uniform sequence stratigraphic framework running from continental shelf to slope on the basis of systematic interpretation, attribute extraction and visualization of 3D seismic data, as well as analysis of drilling and logging data, while applying the standardized sequence stratigraphy theory to the Middle Miocene (around 13.8 Ma) shelf break-to-slope area in deep water in the Pearl River Mouth Basin (PRMB). As shown by the newly established framework, deposit sedimentary sequences in both transgressive systems tract (TST) and highstand systems tract (HST) are extremely thin as a whole; foreset beds of the falling stage systems tract (FSST) and lowstand systems tract (LST), however, are much thicker, and bottomset beds (mainly of deep-water fan) are widely developed in the LST. In a nutshell, the establishment of deep-water sequence stratigraphic framework is supposed to have a holistic consideration from shelf break to deep-water areas at first; 3D systematic comparison of seismic events is to be followed while analyzing the evolutionary features of "Source-to-Sink" system, with a view to better dissecting the system tracts and understanding the coupling relationship of shelf, slope and deep-water sedimentary facies.