## 6 Conclusions  
Under microscope observation, it is evident that the western Kendewula granitoids of the EKOB are mainly composed of mineral grains and the whole-rock geochemistry reveals extremely high SiO\({}_{2}\) contents, alkali and light rare earth element enrichment, positive anomalies of Zr and Ga, negative anomalies of Sr, Ba and Eu, and values of Nb and Ta close to the reference values of crustal rocks. Moreover, we find \(\epsilon\)Hf(t) values of -4.3-3.69, Hf model ages of tDM2 = 1.0-1.2 Ga, and \(\epsilon\)Hf(t) values that are positive and low. Thus, the exposed granites and potash-feldspar granites in Kangduolha west of the eastern Kunlun Mountains are A2-type granites. The magma source is mainly crustal, with the limited participation of mantle materials. Precise zircon U-Pb dating geochronology (zircon U-Pb ages: 413.7-417.7 Ma) confirms that the EKOB enters a post-orogenic extensional stage during the Early Devonian. The asthenospheric upwelling of asthenospheric mantle triggered by crustal detachment and partial melting of the crust is the reason for the flare-up of A2-type granites during this period.  
Figure 11: Late Paleozoic post-orogenic extension model of the EKOB (modified from [23]). NKT—North Kunlun Terrane; SKT—Southern Kunlun Terrane; CKM—Central Kunlun Melange; CLM—Continent Lithosphere Mantle.  
Figure 10: Tectonic setting discriminant diagrams of the west Kendewula region, eastern EKOB (based on [90]): (**a**) Y + Nb vs. Rb diagram; (**b**) Y vs. Nb diagram; (**c**) R1 vs. R2 diagram; (**d**) Yb + Ta vs. Rb diagram, with VAG (volcanic arc granite), ORG (ocean ridge), WPG (in plate granite) syn-LOG (late orogen granite), POG (post-orogenic granite), post-COLG (post-collisional granite); syn-COLG (syn-collisional granite).  
**Supplementary Materials:** The following supporting information can be downloaded at [[https://www.mdpi.com/article/10.3390/app15126661/s1](https://www.mdpi.com/article/10.3390/app15126661/s1)]([https://www.mdpi.com/article/10.3390/app15126661/s1](https://www.mdpi.com/article/10.3390/app15126661/s1)); Data compression package. \"Supplement S1: Test data\" is the result of the analysis of major and trace elements, \"Table S1: The ages of the difente geologic units from various terranes in the East Kunlun Mountains\" is mentioned in the caption of Figure 1 in the text.  
**Author Contributions:** Conceptualization: B.-S.D. and W.-Q.W.; Methodology: B.-S.D. and G.-H.W.; Software: P.-L.Z.; Validation: G.-H.W.; Investigation: Z.-J.H., P.Z., Z.-L.D., J.-Q.Z. and C.B.; Data Curation: [PERSON]-S.L. and B.-S.D.; Writing--Original Draft: B.-S.D.; Writing--Review and Editing: G.-H.W. and W.-Q.W.; Visualization: P.-L.Z. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This study was financially supported by the Kunlun Talent-Advanced Innovation and Innovative and Entrepreneurial Talent Project of Qinghai Province (20221201), the 1:50,000 mineral exploration and geological survey of the Hongshui (Gulang County), Jingtai region, Gansu Province (202248), the Special Support Fund for the Sixth Batch of Ten Thousand Person Plan Teachers (204301001), and the Development Fund ([PERSON] Wang, F02041).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The original contributions presented in this study are included in the article and Supplementary Material. Further inquiries can be directed to the corresponding authors.  
**Conflicts of Interest:** Author [PERSON] was employed by the company Xidihuiyou Mining Technology Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.