论文部分内容阅读
沉积物中Ｆｅ~（３＋）／Ｆｅ~（２＋）的值与形成时的古温度有益指数关系。假定Ｆｅ~（３＋）／Ｆｅ~（２＋）的值沿剖面的变化具有自相关性，那么它所反映的古温度变化是一条分形曲线。本文以庐山大校场剖面为例，根据孢粉和Ｆｅ~（３＋）／Ｆｅ~（２＋）的测试数据，建立了一个推算古温度的非线性公式。据此推算的古温度表明，本区中更新世以来共有３次明显的冷暖波动，最高年均温在２２℃左右，最低达３℃左右，出现在末次冰期。未发现有低于０℃者。由粒度分数维的概念，推导出的计算公式可作为混杂堆积物粒度分布特征的度量指标。根据计算，该剖面主要接近于泥石流和石冰川的粒度分数维，而与冰碛物的粒度分数维有较大差别。综上得出，本区沉积物成因主要是间冰期季风气候下的山地泥石流和沟谷流水的洪－冲积及冰期干冷的冰缘环境下的冻融堆积。
The exponential relationship between Fe ~ (3 +) / Fe ~ (2+) in sediments and ancient temperature at the time of formation. Assuming that the value of Fe ~ (3 +) / Fe ~ (2+) has an autocorrelation along the change of profile, the change of paleotemperature it reflects is a fractal curve. In this paper, taking the section of Lushan University as an example, a non-linear formula for calculating ancient temperature was established based on the test data of sporopollen and Fe ~ (3 +) / Fe ~ (2+). The paleo-tem- peratures calculated from this show that there have been three obvious fluctuations in temperature since the middle Pleistocene, with the highest annual average temperature around 22 ℃ and the lowest about 3 ℃, which occurred in the last glacial period. No one below 0 ℃ was found. The calculation formula derived from the concept of particle size fraction can be used as a measure of the particle size distribution characteristics of the mixed sediments. According to the calculation, the profile is mainly close to the particle size fractional dimension of the debris flow and the glacier, but differs greatly from the particle size fraction of the moraine. In summary, the sediments in this area are mainly caused by freeze-thaw accumulation in the mountainous debris flow and flood-alluvium in the monsoon climate during the interglacial monsoon climate and in the freezing and frost environment during the ice age.