Gneiss dome is an important structural style formed during orogenic exhumation. The Markam lithium deposit, located in the Markam gneiss dome at the hinterland of the Songpan- Ganzi orogenic belt, is composed of the Taiyanghe granodiorite and the Keryin granite in the core, with Late Triassic metamorphic sedimentary rocks in the mantle, whose protoliths were Triassic abyssal and bathyal flysch and turbidity deposits. A large number of pegmatite sheets and dykes were intruded into the meta- sedimentary rocks. Through field geological investigation and microstructural analysis, three stages of structural deformations superimposed on the earlier compressional deformation are identified in the Markam gneiss dome: the first stage deformation (D1) is a top- to- the- south large- scale Markam detachment fault (MRKD), which separates the granitoid core from the overlying Upper Triassic meta- sedimentary rocks; the second stage deformation (D2) is the “domal structure”; the third stage deformation (D3) introduces a near E- W trending Cenozoic thrust fault. New zircon U- Pb geochronological data reveal that the crystallization ages of the Taiyanghe and Keryin granitoids are ca. 226~212 Ma and ca. 224~218 Ma, respectively. In addition, zircon U- Pb dating of syn- tectonic pegmatites in the MRKD reveals ages of ca. 212~207 Ma, while undeformed pegmatitic dykes (including spodumene- bearing veins) have ages of ca. 200~190 Ma. We suggest that during the early compressional orogeny, granites emplaced at 220~212 Ma, resulting in middle- low pressure Barrovian metamorphism. Then, the top- to- the- south detachment shear zone associated with metamorphic core complex structure was formed during the transformation from deep compressional to shallow extensional (212~207 Ma). It also resulted in the upwelling of granitic magma and the formation of gneiss dome. Since 200~190 Ma, a large number of reticular pegmatites (including spodumene- bearing pegmatites) intruded in the meta- sedimentary rocks in the mantle zone. The formation of lithium deposits in the accumulated fluid at the top of the plutonic core is the result of both fractional crystallization and high temperature extraction of Li from the country rocks. We conclude that the Cenozoic thrust fault has uplifted the Keryin and Taiyanghe granitoids in the north, simultaneously deeply burying the meta- sedimentary rocks in the south. Therefore, it has created a favorable condition for the preservation of the lithium deposits.