Pedigree mapping of cogenetic granitoids:A case study of Baoder Stone Forest granitic pluton in Erlian, Inner Mongolia

Unit and superunit mapping has been popularized in China after the development of the cogenetic magma from the 1980s. However, more and more problems cropped out in the mapping practice with the development of the magma theory, and the early stage mapping method of "litholiogy plus epoch" was used again. Whether the application of pedigree mapping in the new stage geological mapping is suitable or not is worth discussing. The Baoder Stone Forest granitic pluton on the border area of Mongolia and China was selected to perform mapping. It is shown that the rock types in this pluton are complicated, including~160Ma coarsemiddle grained porphyritic hornblende biotite monzogranite and 140~124Ma middle-fine grained monzogranite. The rock types are similar, but there are differences in the intrusive ages and mineral structures of these monzogranites, and the main difference is the grain size. They formed in the same regional extensional background by the evolution of the cogenetic granitic magma. They can be divided into two sequences of the Late Jurassic and the Early Cretaceous, as well as five units. Pedigree mapping is still applicable and necessary for the cogenetic granitoids with similar ages and homologous origin, but it must be carefully used and do not expand to practical mapping of all granitoids.