Abstract:

Stratum thickness can reflect tectonic subsidence and/or uplift. After compiling stratigraphic data of all wells in the
Sanhu area of Qaidam basin, the present stratum thickness was calculated, and isopach maps of different periods were drawed.
These maps show that the formation history of the anticline was not uniform, and the structure started to form from the northeast to
the southwest. Yikeyawuru, Nan Linqiu, and Tuo Fengshan anticlines were formed first and they have been the syn-depositional
anticline since the Quaternary. Then Taijinaier and Sebei 2 began to uplift, which was followed by Sebei 2. Tainan anticline was
the youngest and Sedong nose structure began to uplift after k1 was deposited. No anticlines were formed in the southern slope
until today. The speeds of their uplift are not even, and the speed gradually increased, especially, the anticlines had a tendency
for rapid uplift after k5 was deposited. The understanding of tectonic evolution history is very helpful to search for favorable zones
where low-amplitude structures were developed.

Key words: Sanhu area, stratum thickness, anticline, evolution history, Quaternary exploration significance