西湖凹陷东坡渐新统花港组下段粗碎屑体基准面旋回分析

Analysis of Base Level Cycles in Coarse Lower Huagang Formation of Oligocene on Eastern Slope of Xihu Sag

肖剑南 陈晶 陈琳琳 李昆

XIAO Jiannan CHEN Jing CHEN Linlin LI Kun

中国石油化工股份有限公司上海海洋油气分公司勘探开发研究院, 上海 200120; 中国石油化工股份有限公司上海海洋油气分公司, 上海 200120

Institute of SIONPEC Shanghai Offshore Oil & Gas Company, Shanghai 200120, China; SINOPEC Shanghai Offshore Oil & Gas Company, Shanghai 200120, China

东海西湖凹陷东坡渐新统花港组下段粗碎屑体陆相地层，可以通过基准面旋回对比方法建立层序地层格架。以构造演化阶段定义长周期旋回；通过体系域分析及短期旋回叠加样式深化中期基准面旋回研究，提出了水进域中“高可容空间向上变浅半旋回”的新特点；而钻井岩心分析表明：粗碎屑体微相变迁未必与水深变化有关，因此不适宜定义短期、超短期旋回。

To the terrestrial coarse clastic strata in the lower Huagang Formation of Oligocene on Eastern slope of Xihu Sag, East China Sea, the sequence stratigraphic framework can be established by comparing the base level cycles. Long-term cycles can be defined by tectonic evolution stages. In the classification of medium-term cycle by system tract analysis and the stacking pattern of short-term cycles, a new feature reveals, i.e. a semi-cycle of accommodation space shallowing-upward can be identified under background of TST. The observation of core samples indicates that the micro-facies alteration of coarse clastic rocks is not necessarily related with the change of water depth, unsuitably used to define the short-term and ultra short-term cycle.

https://doi.org/10.3969/j.issn.1008-2336.2017.04.012