黄土和沉积岩中分离方解石和白云石的方法实验

采用不同浓度的ＨＣｌ、ＨＡｃ、ＮＨ４Ａｃ及ＮＨ４Ａｃ－ＨＡｃ缓冲深液对典型黄土剖面的黄土样品进行了系统的浸取实验，结果表明，稀ＨＡｃ是分离方解石与白云石的最佳深剂，在浸取实验中对１４种不同元素含量进行测试，多数元素的含量有变化，用稀ＨＡｃ溶液浸取所得的浸取注中＾８７Ｓｒ／＾８６Ｓｒ的测定结果与使用稀ＨＣｌ浸取的浸取液中＾８７Ｓｒ／＾８６Ｓｒ测定值有一定的差别，方法可满足在古气候研究中对不同成因碳酸盐利用的要求。

A Method for Separation of Calcite and Dolomite in Loess and Sedimentary Rocks

In this paper,different concentration of HCl, HAc, NH 4Ac and NH 4Ac HAc buffer solution have been used to dissolve the loess samples from the representative profile in Loess Plateau and 14 elements in samples were determined. The results show that the contents for most elements in leaching solutions are quite different when different sample dissolving reagents were used and the sample dissolving method with dilute HAc solution is proved to be the best one for separating the calcite and dolomite in the loess. The significant difference of 87 Sr/ 86 Sr isotope ratios in loess samples is also found when sample dissolving reagents of dilute HAc solution and the dilute HCl solution were used. The method can meet the requirements in paleoclimate and paleoenvironment research.