The Gongcai and Qinganlin plutonic complexes in the Danba Domal Terrane, eastern Songpan-Ganze Fold Belt, consists of ca. 860Ma adakitic tonalities and ca. 830Ma high-K granites, respectively. Samples from the Gongcai complex have variable SiO2 (66.7–72.1wt%), high Al2O3 (14.3–17.7wt%), low alkalis (5.71–7.07wt%), and high Sr (576–1309ppm) and low Y (2.2–10.4ppm) contents, similar to typical adakites. The Qinganlin complex possesses higher SiO2 (70.9–73.3wt%) and lower Al2O3 (13.5–14.2wt%), and variably higher K2O contents (1.2–3.8wt%) than the Gongcai complex. On the chondrite-normalized REE diagram, both complexes are enriched in LREEs, but the Gongcai complex display strongly fractionated or concave patterns ((La/Yb)N=7–33; (Gd/Yb)N=1.5–4.4) with weakly negative to slightly positive Eu-anomalies (Eu/Eu*=0.89–1.25), while the rocks of the Qinganlin complex exhibit relatively flat HREE patterns ((La/Yb)N=6–10; (Gd/Yb)N=1.3–1.6), with pronounced negative Eu-anomalies (Eu/Eu*=0.56–0.67). Their primitive-mantle normalized spidergrams are all characterized by negative Nb–Ta and Ti anomalies and positive Pb spikes. Comparatively, most Qinganlin granite samples have higher levels of LILE, e.g. Rb, Cs, and HFSE, e.g. Zr, Nb, Hf, Ta, Y, but lower transitional metal elements, e.g. V, Cr, Ni, Co, than those of the Gongcai samples. The samples from the Gongcai and Qinganlin complexes have high positive zircon ɛHf(t) values (+3.2 to +8.4 and +5.5 to +12.6, respectively) with Mesoproterozoic to early Neoproterozoic two-stage Hf-isotope model ages (1.22–1.56Ga and 0.93–1.23Ga, respectively), but show distinctive ɛNd(t) values (+1.67 to +3.40 and −4.34 to +0.74, respectively). We suggest that the precursor magma of the ca. 860Ma Gongcai tonalites was derived from partial melting of basaltic oceanic crust modified by minor slab-derived components with residual garnet+amphibole in the source, and their relatively lower Mg# (37–53), Cr and Ni compared to the Cenozoic adakites indicate less interaction between slab melt and mantle wedge at the initial subduction stage along the western margin of the Yangtze Block at ca. 860Ma. Because of the wide range of positive ɛHf(t) values but variable low ɛNd(t) and high 87Sr/86Sri values, the parental magma of ca. 830Ma high-K Qinganlin granites is considered to be produced by re-melting of newly formed mafic crust with variable mixing of local Paleo-Mesoproterozoic sedimentary materials under extensional setting, supporting that subduction was stopped at. 830Ma and the tectonic regime started to change from compression to extension. Both of the two plutonic complexes underwent later Mesozoic regional metamorphisms and migmatization (ca. 169Ma and ca. 153Ma) as a result of a nearly E–W post-orogenic extension. The nature and petrogenesis of the closely associated adakitic tonalites and high-K granites therefore provide effective perspective into the ∼860Ma initial subduction system caused by an eastward subduction of a young and hot oceanic crust beneath the western Yangtze Block, and a later ∼830Ma tectonic transition on the Yangtze Block. If an Andean-type continental arc existed, the Yangtze Block was possibly at a marginal position of Rodinia supercontinent in the Neoproterozoic.