济阳坳陷馆陶期水系及沉积环境分析

济阳坳陷上第三系馆陶组为冲积扇—河流沉积.坳陷周围隆起区及内部凸起区的山前带发育冲积扇沉积.而坳陷内为大片河流沉积.馆陶早期为辫状河沉积;中晚期为曲流河沉积.济阳坳陷内发育有三大水系,各水系流经沾化东部后继续向东流入渤海,故推断现渤海海域地区有较厚的馆陶组,河道砂体、三角州砂体和湖泊砂体均应发育.此地区是今后油气勘探的有利场所.

PALAEODRAINAGE SYSTEMS AND SEDIMENTARY ENVIRONMENT ANALYSIS OF GUANTAO FORMATION IN JIYANG DEPRESSION

In the Jiyang Depression, the Guantao Formation of the Neogene System consists of alluvial fan to fluvial deposits. Alluvial fan deposits were well developed in the areas of marginal and interior rises around and in the depression. Most of the interior of the depression was covered with fluvial deposits. Braided river deposits were dominant during the early period of the Guantao Formation, and meandering river deposits were dominant during the middle to late period of the Guantao Formation. Three palaeodrainage systems had developed in the Jiyang depression. Each palaeodrainage system discussed above flowed continuously to the eastern Zhanhua area. then eastward to the Bohai Sea. It can be inferred that the Guantao Formation is much thicker in the present Bohai Sea area than that in other areas and channel sandstone, delta sandstone and lacustrine sandstone must be well developed. This has made this area a promising place for oil and gas exploration.