碳酸盐矿物和碳酸盐岩天然热释光的实验研究

AN EXPERIMENTAL STUDY TO THE NATURAL THERMO LUMINESCENCE(TL) CHARACTERISTICS OF INDIVIDUAL MINERALS OF CARBONATE AND CARBONATE ROCK

碳酸盐岩的天然热释光强度变化特征所表征的地质信息,是一个值得探讨的研究方向。通过对碳酸盐单矿物及其人工混合物和采自云南省三叠系个旧组的碳酸盐岩进行热释光实验研究,测定出①碳酸盐单矿物和碳酸盐岩的最优实验条件;②碳酸盐单矿物方解石和白云石热释光曲线形态;③碳酸盐单矿物人工混合物的峰形和峰值大小与其物质含量有关;④同一剖面的碳酸盐岩的天然热释光曲线各峰的强度变化趋于一致。

The thermo luminescence(TL) is a particular phenomenon of gleam and it has been extensive used in the many research fields.There are,however,little researches to introduce the measuring condition of natural thermo luminescence of carbonate sample.The paper discusses the measuring condition of the individual carbonate minerals and the carbonate rock and analyses the natural thermo luminescence(NTL) curves characters of the samples.As it has been found that the TL fluctuations are closely correlated to the oxygen isotope curves in the past study and references,the TL curve characters might be taken as a proxy for studying the marine sediment and sedimentary environment.The measurement result quality decide geological interpretation how to make the measurement result reach reasonable permission.Some factors can affect the accuracy of TL intensities and TL spectra are numerous.For example,the sample's grain size,heating temperature and other factors affect all the results in the measurement.In this paper,some of preliminary experiment researches are carried out,and the optimum condition is offered in measurement.Final,this article ascertain measuring condition of carbonate sample(the amount to be used is 20 mg;temperature province is from 50℃ to 450℃;heating rate is 5°/S).The TL curve characters of carbonate have double peaking,and the dolomites' assume terraced.The TL curve characters and the TL intensities of mixtures are related to rate of ingredient.And the natural thermo luminescences(NTL) of carbonate rocks from Gejiu grope in Yunnan province were studied for palaeoenvironmental changes.And it is found that drift of two peaks intensities is similar and all of them can represent the palaeoenvironmental changes.