1. Loess in different climatic zones across the Chinese Loess Plateau contains an ultrafine component with a consistent modal grain size of 0.37 μm and a variable proportion of 4 to 10%.
2. The ultrafine component is composed mainly of clay minerals, mostly illite, with significant amounts of kaolinite and chlorite.
3. Variations in the ultrafine component reflect the history of pedogenesis during the Late Cenozoic, with two abrupt changes at 2.6 and 0.6 Ma.
The article “The Ultrafine Component in Chinese Loess and Its Variation Over the Past 7·6 Ma: Implications for the History of Pedogenesis” by Donghuai Sun et al., published in Sedimentology (2011), is generally reliable and trustworthy. The authors provide detailed evidence for their claims, including grain-size data from different climatic zones across the Chinese Loess Plateau, quantitative X-ray diffraction analysis, and results from a loess section with a basal age of 7·6 Ma in the central Loess Plateau. The authors also present both sides equally by noting possible risks associated with their findings as well as unexplored counterarguments that could be considered when interpreting their results. Furthermore, there is no promotional content or partiality evident in this article; instead, it provides an objective overview of its subject matter without any bias or one-sided reporting. In conclusion, this article can be considered reliable and trustworthy due to its thoroughness and lack of bias or unsupported claims.