The quantification of the whole rock mineralogical composition of clay-rich sediments can be achieved by quantifying the detailed clay mineralogy in a fraction which concentrates most of the clay minerals (often the fraction <2 μm) and integrating this information with a mineralogical composition derived from modeling a randomly oriented powder diffraction pattern of the bulk sample. Although this approach is effective, as evidenced by its performance in the Reynolds Cup, the representativeness of the isolated fraction for the entire clay mineral population is not indisputable, as clay minerals are known to occur in coarser fractions as well. Therefore, this study investigates the representativeness of the fraction <2 μm by isolating and quantifying the mineral composition of all size fractions of the Rupelian Boom Clay (Belgium). In addition, the study of size fractions is used to quantify and correctly integrate muscovite into a whole rock mineral composition.

量化富含粘土沉积物的整个岩石矿物学组成可以通过对浓缩大部分粘土矿物的馏分中的详细粘土矿物学进行定量（通常分数<2μm）并将此信息与由建模散装样品的随机取向粉末衍射图。尽管这种方法是有效的，如雷诺杯上的表现所证明的那样，但对于整个粘土矿物种群而言，分离出的馏分的代表性并不是无可争辩的，因为已知粘土矿物也存在于较粗的馏分中。因此，本研究通过隔离和量化Rupelian Boom Clay（比利时）的所有大小级分的矿物成分来研究级分<2μm的代表性。