| The North Qilian Orogenic Belt, as one of the typical orogenic zones in the world, is a key region for studying plate tectonic evolution and geodynamic processes. In the development of geosciences, geologists have been always paying close attention to the very mobile interaction between crust and mantle, intensive interchange processes of the lithospheric materials and energy, and remarkable magmatic mineralization in the eastern section of the North Qilian during early Paleaozoic period. The study results of comprehensive geology show that the eastern section of North Qilian may been divided into the Alaxa Paleo-continental margin, Laohushan back-arc basin remnant, Baiyin continental marginal arc, subducted complex zone of the North Qilian, and the Central Qilian Block from north to south, and that the eastern section of the North Qilian was obviously characterized by the tectonic processes of rifting with continental tholeiite to alkaline basalts from late period of Neoproterozoic to early period of Early Paleaozoic, and by tectonic evolution of the spreading, subduction of the paleo-Qilian ocean, forming Baiyin continental marginal arc and Laohushan back-arc basin, to finally plate collision and orogeny. The study results of petrology and geochemistry are to originally reveal and demonstrate: 1) the early Paleozoic granodiorites from Yindongliang in Quwushang, located in the Alaxa Paleo-continental margin, north of Laohushan back-arc basin remnant, are adakites, similar to the typical adakites from circum-Pacific region. They have high Al2O3 (>15% (w %)), Na2O (>4.0% (4.51% - 4.92% (w %)), Na2O/K2O = 1.63- 2.40, and SiO2>56% (w %), and low K2O contents (1.96-2.77 % (w %) ), belonging to calc-alkaline series; and high Sr (599—691× 10-6) low Y (6.3-8.1 ×10-6)andYb (Yb<1.9×10-6)contents, Sr/Y>40(81-94), Y/Yb>10, La/Yb>20 (22-45), and but with higher Mg# (58 - 64) , Ni (31-38 ×10-6) and Cr (35-43 ×10-6) contents compared with the typical adakites, so called as high-Mg adakite,...
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