Dajiuba buried fault (No.4 fault): It is the boundary fault between Kumukuli micro-landmass and Central Kunlun micro-landmass. The fault is basically covered by Quaternary diluvium, but it is reflected in Quaternary diluvium. The eastern part is basically along the Kurukbaitilik Tagenengsu Valley, and the western part is located at the northern foot of Qiertag Mountain, where linear springs gush out. Generally speaking, the strike of the buried fault is about NW-SE (300 ~ 120).
The east-west extension of Dajiuba buried fault has been unclear in the region, and most of it is covered by Quaternary flood to the west. However, due to the low level of regional geological survey (only 1: 1 10,000 regional survey), its east extension has been unclear, and it is doubtful whether it can be connected with the Kunzhong fault in Qinghai. According to this regional investigation and research of regional data, we think that Dajiuba buried fault should be connected with Kunzhong fault, which is the western extension of Kunzhong fault. The basis is as follows: (1) There are a lot of late Paleozoic granites in the north of Kunzhong fault in Qinghai, but there are few intrusive rocks in the south of the fault, which is similar to the geological situation in Dajiuba area. The late Paleozoic granite intrusion in the northeast of Dajiuba is also a part of the magmatic belt in the north of Kunming, and its petrology is one of them. (2) The north of Kunzhong fault in Qinghai is dominated by a set of lower Proterozoic medium-deep metamorphic rocks, on which a set of cover rocks representing the active environment of Late Paleozoic (Late Devonian-Carboniferous) is developed. The lithology is characterized by clastic rocks mixed with tuff and volcanic rocks, which is similar to the rock assemblage of Dajiuba Formation of Lower Carboniferous in the investigation area.