The Origin of Pore-Water and the Study of Sandstone Diagenetic Facies of Fu-Yang Formations (K₁q⁽³⁺⁴⁾,Northern-Eastern Songliao Basin,NE China (Cretaceous)

Key words: 
• diagenesis /
• diagenetic factes /
• pore-water origin /
• hydrodynamic field

Abstract: The sandstones in Fu-yang Formations deposited by fluvial-lacustrine sedimentary system have more than 70 percent of unstable fragments such as feldspar and volcanic-rock fragments.Based on thin-section analysis,XRD, SEM, electronprobe and fluid inclusion analysis, the progressive diagenetic sequence for the sandstones could be summarized. But, the diagenetic property is also controlled by ①pore-water geochemistry,② burial depth and geothermal gradient, and ③sedimentary environments and so on, which caused the diagenetic environments fairyly different.The local hydrodynamic units, with different origins and compositions of pore-water, is the main factor, which controls the kinds of diagenetic factes. The planar delimitation lines of local hydrodynamic units are unanomalous with those of local porewater geochemistry units and diagenetic factes.In the study area, four types of diagenetic factes can be recognized: meteoric water infiltration diagenetic factes, burial water diagenetic factes, mixture water diagenetic factes and paleo-evaporation water diagenetic factes.