Important discoveries were made in the regional geological survey in southern Jilin, and the Paleoproterozoic lithostratigraphic sequence was preliminarily established

Liaoning Provincial Geological Survey Institute has made a series of important discoveries on basic geology in the 1:50000 regional geological survey of Daoweizi, Badynastic and Qinghe sheets in Jilin Province, and the relevant projects have recently passed the acceptance of the expert group.

The regional survey project is located in the south of Jilin Province. In the past three years, the project team members of Liaoning Institute of Geological Exploration have broken the long-term inherent thinking and concept, applied new theories and methods such as the ocean plate, carried out a lot of field surveys and indoor research, and made a series of important achievements and progress: preliminarily established the Paleoproterozoic rock strata sequence in the work area, and proposed a preliminary comparison scheme for the division of the Laoling Group and the "North Liaohe Group". Through structural rock mapping, the original "Ji'an rock group" is defined as a subduction accretion complex belt, where ophiolite blocks such as dunite, gabbro and gabbro are found; The high magnesium andesite was first mapped in the area, and the zircon age was 2.342 billion years; The high-pressure basic granulite and the glaucophane schist assemblage hosted in the nappe are mapped for the first time; The sequence of oceanic islands and seamounts, as well as the widely distributed submarine fans and pelagic sediments were identified. A series of nappe structures are found in the area. The nappe body is composed of Ji'an subduction accretion complex and is pushed over the Laoling Group. In the subduction accretion complex belt, two phases of intrusive rock associations, including tonalite trondhjemite granodiorite and monzogranite syenogranite alkali feldspar granite, have been identified. There are 4 uranium and thorium ore occurrences, 1 graphite ore occurrence, 1 copper gold ore (mineralization) occurrence, as well as multiple pyrite, boron, graphite and other mineralization information sites.

According to the evaluation of the expert group, the series of discoveries made by the project team in the south of Jilin Province have provided an important basis for the formation and evolution of the Jiaoliao Jilin belt in the east of the North China Craton and the dynamic process of micro landmass aggregation collage, as well as a solution for the division and comparison of the Ji'an Group, the Laoling Group and the Liaohe Group in the north and south.