Periodicity of Element Changes in the Upper Devonian Strata of Dachang Area, Southern China——A Case Study of Spectral Analysis

Power spectral analysis is discussed and an exmple of its application to a geochemical stratigraphic profile is presented.In the Dachang area,all major elements,as well as the maximal sedimentary trend factor(MSTF),demonstrate consistent change periodicity,but are out-of-step with cach other.This can be explained by sedimentogecochemical consideration.The results of power spectral analysis enable geochemists to group elements on the basis of the distribution of their changed periods,and to interpret some special geological and geochemical situations.

Power spectral analysis is discussed and an example of its application to a geochemical stratigraphic profile is presented. In the Dachang area, all major elements, as well as the maximal sedimentary trend factor (MSTF), demonstrate consistent change periodicity, but are out-of-step with each other. This can be explained by sedimentogeochemical consideration. The results of power spec- tral analysis enable geochemists to group elements on the basis of the distribution of their change periods, and to interpret some special geological and geochemical situations.