物源供给指数及其对滩坝发育程度的控制作用

INDEX OF PROVENANCE PROVISION AND ITS CONTROLLING ACTION ON THE DEVELOPMENT OF THE BEACH AND BAR

物源供给速率是控制沉积作用的基本因素。采用砂地比、粒度、层理规模、岩性、分选系数、重矿物、石英、长石和岩屑含量等参数在归一化的基础上定量求取了东营凹陷南坡东段物源供给指数，认为其分布在平面上具有东南部、西北部、南部地区较高而中部、东北部地区较低的特征。南坡地区物源供给指数与砂岩厚度呈正比，与碳酸盐岩厚度呈反比，据此预测了该区沉积相的分布情况：物源供给指数介于0．03～0．19时为碳酸盐岩的发育区域，砂岩滩坝多发育在大于0．16的区域，泥岩多发育在小于0．12的区域。

The rate of provenance provision is the basic element that controlls the sedimentation. With the help of the following normalized parameters ： sand-strata ratio, grain grade, bedding scale, lithology, sorting coefficient, the contents of the heavy minerals, quartz, feldspar and debris and so on, the index of provenance provision is quantitatively obtained in the eastern part of South Slope of Dongying Sag. The understanding indicates that the characteristics of much higher southeast, northwest and south parts and moreover rather lower middle and northeast regions are possessed in the distributions of planar horizon. The indices on the east slope has the direct ratio of sandstone thicknesses and the inverse proportion to the carbonate layer＇s thicknesses. Just according the above a- chievements, the distributions of the sedimentary facieses are predicted in the region： when the index lies within 0.03 -0. 19, the carbonate layers are well developed; the sandstone beach and bar are mostly developed in the area with the index greater than 0. 16; the mudstone is generally developed in the area less than 0. 12.