长岭断陷龙凤山地区营城组沉积特征

Sedimentary characteristics of Yingcheng formation in Longfengshan area of Changling fault depression

长岭断陷龙凤山西部构造带发育辫状河三角洲沉积体系,发育三角洲平原、前缘2种亚相6种微相,东南斜坡带发育扇三角洲沉积体系,发育扇三角洲前缘亚相4种微相。营城组沉积时期共存在三个方向物源供给,即西南部的变质岩物源区、南部的岩浆岩物源区和东南部的岩浆岩物源区,多物源导致岩矿组分区域分带性强,成分差异较大。来自不同物源的沉积砂体自南向北推进,从营Ⅶ砂组到营Ⅲ砂组沉积时期,物源供给能力增强,沉积范围逐渐扩大。

In the western structural belt of Longfengshan area of Changling fault depression, there developed the braided river delta sedimentary system, two sub-facies of delta plain and delta front, and six microfacies. While in the southeast slope belt, there developed the fan delta sedimentary system, fan delta front sub-facies and four microfacies. In the sedimentary period of Yingcheng formation, there were three kinds of source supplies, namely the metamorphic rock source area in the southwest, the magmatic rock source area in the south and the magmatic rock source area in the southeast. The multi-physical source leads to a strong regional zonation of rock and mineral components and the great difference in composition. During YingⅦ sand group to YingⅢ sand formation sedimentary period, the sedimentary sand bodies of different provenances carried forward from south to north, with increased material supply capacity and gradually expanded sedimentary range.