Granitic pegmatite deposits, which are usually products of orogenic processes during
plate convergence, can be used to demonstrate regional tectonic evolution processes. In the eastern
Tibetan Plateau in China, the Jiajika, Dahongliutan, Xuebaoding, Zhawulong, and Ke’eryin rare metal
pegmatite deposits are located in the southern, western, northern, midwestern, and central areas of
the Songpan–Ganzê orogenic belt, respectively. In this study, we dated two muscovite Ar–Ar ages of
189.4 1.1Ma and 187.0 1.1Ma from spodumene pegmatites of the Dahongliutan deposit. We also
dated one zircon U-Pb age of 211.6 5.2 Ma from muscovite granite, two muscovite Ar–Ar ages of
179.6 1.0 Ma and 174.3 0.9 Ma, and one columbite–tantalite U-Pb age of 204.5 1.8 Ma from
spodumene pegmatites of the Zhawulong deposit. In addition, we dated one muscovite Ar–Ar age
of 159.0 1.4 Ma from spodumene pegmatite of the Ke’eryin deposit. Combining these ages and
previous studies in chronology, we concluded that the granitic magma in the Jiajika, Xuebaoding,
Dahongliutan, Zhawulong, and Ke’eryin deposits intruded into Triassic metaturbidites at approximately
223, 221, 220–217, 212, and 207–205Ma, respectively, and that the crystallization of the corresponding
pegmatite ceased at approximately 199–196, 195–190, 189–187, 180–174, and 159 Ma, respectively.
In this study, we demonstrated that the peak in magmatic activity and the final crystallization age
of the pegmatite lagged behind one another from the outer areas of the orogeny belt to the inner
areas. The pegmatite–parented granitic magmas were sourced from Triassic metaturbidites that were
melted by shear heating along the large-scale decollement resulting from Indosinian collisions along
the North China block, Qiangtang–Changdu block, and Yangtze block. As a result, the above temporal
and spatial regularities indicated that the tectonic–thermal stress resulting from the collisions of three
blocks was transferred from the outer areas of the orogenic belt to the inner areas. A large amount of
heat and a slow cooling rate at the convergent center of thermal stress in two directions will lead to
crystallization and differentiation of magma in the Songpan–Ganzê orogenic belt, forming additional
rare metal deposits.