关键词: 分形, 庐山地区, 古沉积环境

Abstract: The past study has revealed that there is a close relation between the value of Fe³⁺/Fe²⁺ and the climatic conditions for forming sediments.Viewing the phenomenon at a different angle,the authors found that the sediments with high value of Fe³⁺/Fe²⁺ also have more thermophilous sporopollen. Going a step further.we can find that there is a positive correlation between the value of Fe³⁺/Fe²⁺ and the paleo-temperature for forming the sediments.The positive correlation is similar to a power exponent relation.If the value of Fe³⁺/Fe²⁺ in vertical profile has an autocorrelation,then the value will show a fractal curve.The relation betewwn the Fe³⁺/Fe²⁺ value and paleo-temperature can use a formula to express.that is,T=a+bx^D.where,T is paleo-temperature.x is the value of Fe³⁺/Fe²⁺,a and b are constants,and D is the fractal dimension of the Fe³⁺/Fe²⁺ series.Based on the results of sporopollen identification and the testing data of Fe³⁺/Fe²⁺.this paper establishes a nonlinear formula to infer the paleo-temperature in the area,i.e.T=2.3+0.09x^1.31.Using the above formula to determine the paleo-temperature change in the area since Q₂,we can find that the inferred result has a relative mean deviation of <5%,and this method is more obvious to illustrate the paleo-temperature fluctuation.The inferred result shows that there are 3 times obvious(cold or warm) climate fluctuation in the area since Q₂.During the period.the highest annual mean air-temperature was about 22℃,and the lowest value was 3℃ or so.No minus annual mean air temperature was not found.

Key words: Fractal dimension, Lushan area, Paleo-sedimentary environment