Characteristics and Geological Significances of Fluid Inclusions of Halite in Dongying Sag, East China

摘要

Dongying Sag is a secondary tectonic unit of Jiyang depression, located in the southeast of Jiyang depression in Bohai Bay Basin, China. It’s a typical half-graben fault basin of Mesozoic- Cenozoic eastern China. There are developed three positive structural belts: northern steep-slope, southern gentle-slope and central uplift. And they divide Dongying sag into four subsags: Lijin, Minfeng, Niuzhuang and Boxing (Wu et al., 2013). According to core and logging analysis, there are four sets of salt rock, distributed in Ek1s, ES4xs, ES4xxand ES4 s from the bottom up (Xu et al., 2008). Laterally, salt rock beds are wide-spreading in Minfeng subsag, central uplift, Niuzhuang subsag and Binnan-Lijin areas, especially central uplift to the north where salt rock beds are concentrated developed on a large scale and formed two thickness centers, Fengshen2 and Haoke1- Dongfeng5 (hereinafter referred to as FS2, HK1 and DF5). On the basis of present research situations of salt rock in Dongying Sag, achievements gave priority to salt rock sedimentology, structures related to salt, the sealing property of salt rock and so on, however, lacked the study of salt-related fluid processes. Therefore, this paper gives detailed researches about the characteristics of fluid inclusions in halite of Dongying Sag for the first time, makes a primary study on the relevant geological significances of different types of fluid inclusions, and establishes the foundation for the further researches of salt-related fluid processes in future.