塔里木盆地塔中—顺北地区柯坪塔格组高分辨率旋回层序地层划分

塔里木盆地塔中—顺北地区下志留统柯坪塔格组作为一套典型的海相碎屑岩沉积地层，砂泥叠置关系复杂，仅通过测井曲线形态的传统方法不利于高分辨率层序的精确划分。首先根据地震剖面与测井滤波处理曲线来识别不整合面及相关的整合面，得出长期基准面变化情况；其次用最大熵谱图与合成预测误差滤波划分中期基准面旋回边界；最后从动态最大熵谱中提取出米氏旋回参数，进一步获取带通滤波信号组和天文周期单元，划分短期基准面旋回，最终完成高分辨率层序地层的划分。柯坪塔格组识别出3种三级层序边界类型：连续海侵背景下的T₁型、完整海侵—海退背景下的T₂型、海退为主的T₃型。目的层共划分出4个长期、16个中期以及50个短期基准面旋回。

Stratigraphic division of high-resolution cycle sequence of Kepingtage Formation in Tazhong-Shunbei area， Tarim Basin

As typical marine clastic sedimentary strata， the Lower Silurian Kepingtage Formation in the Tazhong-Shunbei area of Tarim Basin has a complicated sand-mud superimposed relationship. It is not conducive to the accurate division of high-resolution sequence if it is only based on logging lithology and logging curve shape. This paper identifies the unconformity surface and the related integration surface based on the seismic profile event axis and the logging filter curve， which derives the changes of long-term benchmark. The maximum entropy spectrogram and synthetic prediction error filter curve is used to divide the mid-term base-level cycle. Extract Milankovitch cycle parameters from the dynamic maximum entropy spectrum， obtain the band-pass filtered signal group and the astronomical period unit， and divide the short-term base-level cycle. Kepingtage Formation identified three types of tertiary sequence boundary types： T₁ in the case of continuous transgression， T₂ under the condition of complete transgression and regression， and T₃ dominated by the regression， including 4 long-term， 16 medium-term， and 50 short-term data cycles. The results have indicative significance for the formation analysis of sedimentary microfacies under multi-phase hydrodynamic conditions of the target layer.