Appinite commonly occurs in convergent plate tectonic settings and thus can constrain the tectonic evolution of ancient orogens. Geochemical and geochronological analyses were carried out on a newly identified Early Triassic appinitic complex in southeastern Inner Mongolia in the eastern segment of the Central Asian Orogenic Belt. Petrographically, the Luotuochang complex can be divided into two zones: an outer zone of intermediate rocks and inner zone dominated by mafic rocks. A monzonite sample from the outer zone yielded weighted mean zircon ²⁰⁶Pb/²³⁸U ages of 246 ± 1.6 Ma, whereas the gabbro from the inner zone yielded an age of 243 ± 1.2 Ma. The inner zone mafic rocks have SiO₂ contents of 45.56 to 54.27 wt% with high MgO, Cr, Ni and Sr contents, elevated Ba/Nb, Ba/Zr, Rb/Y and Th/Zr, and low TiO₂, Nb/Zr and Nb/Y. These features suggest that the metasomatized lithospheric mantle is the primitive magma source. SiO₂ contents of the outer zone intermediate rocks range from 57.6 to 63.69 wt% and K₂O, Ba and Sr contents are enriched; the ε_Nd(t) (+2.2 to +4.0) and ε_Hf(t) (+8.4 to +13.5) values are also high. These characteristics suggest that the magma of these rocks mainly derived from the mantle with possible juvenile lower crust involvement. Based on these geochemical data and results from regional geological investigations, we propose that the Luotuochang appinitic complex was formed in a post-orogenic extensional setting. Its formation was likely the result of lithospheric delamination, upwelling of new mantle material and partial melting of the overlying lower crust during crustal compression and thickening soon after the closure of the restricted Paleo-Asian Ocean basin.

胃口通常在会聚的板块构造环境中发生，因此可以限制古代造山带的构造演化。在中亚造山带东段的内蒙古东南部，对一个新近发现的三叠纪早期花岗复合体进行了地球化学和年代学分析。岩石学上，罗托场复合体可分为两个区域：中间岩石的外部区域和以镁铁质岩石为主的内部区域。外部区域的蒙脱石样品的加权平均锆石²⁰⁶ Pb / ²³⁸ U年龄为246±1.6 Ma，而内部区域的辉长岩的年龄为243±1.2 Ma。内层镁铁质岩含SiO ₂MgO，Cr，Ni和Sr含量高，Ba / Nb，Ba / Zr，Rb / Y和Th / Zr含量高，TiO ₂，Nb / Zr和Nb / Y含量低时，其含量为45.56至54.27 wt％。这些特征表明交代岩石圈地幔是原始岩浆源。外层中层岩石的SiO ₂含量为57.6〜63.69 wt％，富集了K ₂ O，Ba和Sr。的ε_钕（吨）（2.2至4.0）和ε_的Hf（吨）（+ 8.4至+13.5）值也很高。这些特征表明，这些岩石的岩浆主要来自地幔，可能伴有少年下地壳。根据这些地球化学数据和区域地质调查的结果，我们建议罗托场断层复合体是在造山后伸展的环境中形成的。它的形成可能是岩石圈分层，新地幔物质上升以及地壳压缩过程中上覆下地壳部分融化以及受限制的古亚洲洋盆地关闭后不久增厚的结果。