吉林东部延吉一带,地处长白山脉的北麓,森林密布,第四纪沉积物覆盖严重。在地质上,该区处于华北地台北缘东段与吉黑古生代地槽的交界处以及滨太平洋的构造环境中,形成的构造十分复杂。区内地层出露甚少,花岗岩大面积出露,自太古宙、元古宙到古生代及中生代均有岩浆活动,尤其是海西期花岗岩大面积侵位,形成了本区的主要地质体,其次为燕山 Yanji area in the east of Jilin is located in the northern foot of the Changbai Mountains, with dense forests and serious Quaternary sediments. Geologically, this area is located in the junction of the northern margin of the North China Platform and the Ji’ai-Paleozoic trench and in the tectonic setting of the Pacific Ocean, forming a complex structure. There are few strata exposed in the area and large area of ​​granite is exposed. Magma activities have occurred in both the Archean and Proterozoic regions to the Paleozoic and Mesozoic, especially the large-scale emplacement of Hercynian granites, forming the main geological body in this area, Followed by Yanshan