深水沉积的层序地层单元划分方法探讨——以东营凹陷牛38井为例

Methods for Dividing Sequence Stratigraphic Units of Deep-water Deposition——By Taking Well Niu 38 for Example

以东营凹陷牛 38井沙三段沉积地层为例 ,探讨了深水沉积的层序地层单元划分方法。第一种方法是利用钙质层 ;在纯泥岩和钙质泥岩互层或夹层的沉积地层中 ,纯泥岩钙质泥岩一般组成了一个沉积旋回 ,钙质泥岩位于旋回的顶部。第二种方法是利用深水沉积砂岩 ;在深水砂岩和泥岩互层或夹层的沉积地层中 ,深水砂岩 泥岩构成了沉积旋回 ,深水砂岩位于旋回的底部。第三种方法是利用泥岩中有机碳总量 ;在一个理想的沉积旋回中 ,一般在旋回底部有机碳总量最高 。

By taking Es_3 depositional stratigraphy of Well Niu38 in Dongying Depression for example, methods for dividing deep-water sequence stratigraphic units are discussed. In the first method calcrete is used. In the depositonal stratigraphy composed of pure mudstone and calcareous mudstone as an interlayer or interbed, a sedimentary cycle is made up of pure mudstone-calcareous mudstone. In the 2nd method, deep-water sedimentary sandstone is used. In the depositional stratigraphy composed of interlayer or interbed of deep water sandstone and mudstone, a sedimentary cycle is made up of deepwater sandstone and mudstone, where the deepwater sandstone is on the bottom of the cycle. In the 3rd method the total organic content is used. In an ideal sedimentary cycle, the total organic content is the highest on the bottom of a general cycle, it is getting lower upward.