天文周期约束下的基准面旋回层序划分方法  

The Method for Astronomical Period-Restricted Datum-Cycle Sequence Classification

作　　者：王起琮[1] 

机构地区：[1]西安石油大学,西安710065

出　　处：《新疆石油地质》2009年第4期509-514,共6页Xinjiang Petroleum Geology

基　　金：国家科技重大专项课题(2008ZX05005-004-09HZ);陕西省教育厅专项科研计划项目(08JK408)共同资助

摘　　要：应用离散小波变换法对自然伽马曲线进行了信号分解并对各细节分量进行了频谱分析,确定了各细节分量的优势频率及沉积旋回厚度。根据沉积旋回厚度比例关系与天文周期比例关系之间的对应性,判断出与各天文周期相关的沉积旋回,并在绝对地质年龄约束下估算出各沉积旋回时限。延长组分析结果表明,据各细节分量划分的沉积旋回的时限均为对应天文周期的2倍,如以天文周期作为基准面旋回层序划分的依据,则每个沉积旋回可划分2个基准面旋回层序。该项研究成果表明,以天文周期为依据,以小波变换及频谱分析为手段,可以合理、有效地开展基准面旋回层序的划分与对比,在绝对地质年龄约束下进行地层定年。Through the signal decomposition of gamma ray curves and the spectrum analysis of detailed components using discrete wavelet transform technique, the dominant frequency and sedimentary cycle thickness for the detailed components are determined. According to the corresponding relations between ratio of sedimentary cycle thickness and ratio of astronomical period, the sedimentary cycles related to individual astronomical period are ascertained, and the time limitation of these cycles restricted by absolute geologic age. The case study from Yanchang formation indicates that the time limitation numbers of these cycles classified by detailed components are twice of astronomical periods, that is, taking the astronomical period as classifying basis of datum-cycle sequence classification, the each sedimentary cycle can be divided into two datum-cycle sequences. The research shows that the rational and effective classification and correlation of the datum-cycle sequence can be carried out based on astronomical period, discrete wavelet transformation and spectrum analysis, and the stratigraphic ages are ascertained by restriction of corresponding absolute geological ages.

关 键 词：天文周期 基准面旋回 离散小波 频谱分析 延长组 

分 类 号：P539.2[天文地球—古生物学与地层学]