Permian Erbutu and Kebu Ni--Cu sulfide-bearing mafic-ultramafic intrusions in the central Asian orogenic belt (CAOB) formed in the Andean-style continental convergent margin adjacent to the northern margin of the North China Craton (NCC). The rocks of the two intrusions show arc-like affinity on the primitive mantle-normalized trace element patterns and have ε_Nd(t) ranging from −8.7 to −4.2, which are interpreted to be related to derivation from the metasomatized, enriched, subcontinental lithospheric mantle (SCLM) beneath the NCC. Using the olivine-orthopyroxene-spinel oxygen barometer, the magma fO₂ of the Erbutu and Kebu intrusions was calculated to be from FMQ-0.8 to FMQ + 0.2, and from FMQ + 1.3 to FMQ + 2.0, respectively. The sulfides in the rocks have δ³⁴S_CDT ranging from +5.3 to +7.5‰ for the Erbutu intrusion and from +2.0 to +4.5‰ for the Kebu intrusion, much higher than that of the MORB mantle (δ³⁴S_CDT = −1.5 to 0.6‰). The rocks of the Erbutu and Kebu intrusions have δ¹³C ranging from −26.1 to −20.4‰ and − 26.4 to −20.9‰, respectively, similar to that of organic carbon in the crust (δ¹³C = −28 to −20‰), but much lower than that of the MORB mantle (δ¹³C = −7 to −5‰). These may indicate the addition of externally derived sulfur (S) and organic carbon into the magmas, which would increase S contents and decrease S solubility of the magmas, respectively, triggering sulfide saturation of the magmas. It is noted that the sulfide saturation of the Erbutu intrusion was mainly related to the addition of externally derived sulfur in the magmas as sulfur is generally present as S²⁻ species in the low-fO₂ magmas. Both intrusions have trace element patterns and ε_Nd(t) values nearly identical to those of the Permian Elitu volcanic rocks in the same region, indicating that they were likely genetically linked. The Elitu volcanic rocks show negative correlation of (Gd/Yb)_N with >3.0 wt% MgO, which is interpreted as the primary magmas of the rocks may have experienced early garnet fractionation at high pressure (e.g., 0.8 to 2.0 GPa). The calculated thickness of the crust in this region is ~56 km, equivalent to ~1.7 GPa in pressure. The primary magmas of the Erbutu and Kebu intrusions were produced by partial melting of the enriched SCLM beneath the thickened crust and are likely Ni-enriched, which is also crucial to the economic Ni--Cu sulfide mineralization in the Andean-style continental convergent margin in the CAOB.

中亚造山带（CAOB）中的二叠系Erbutu和Kebu Ni-Cu硫化物镁铁-超镁铁质侵入体形成于与华北克拉通（NCC）北缘相邻的安第斯式大陆收敛带中。这两个侵入体的岩石在原始地幔归一化的痕量元素模式上显示出弧状亲和力，并且_εNd（t）的范围为-8.7至-4.2，这被认为与衍生自交代，富集，次大陆的岩石有关NCC下的岩石圈地幔（SCLM）。使用橄榄石-邻-邻二甲苯-尖晶石氧气压计，岩浆f O ₂计算得出的Erbutu和Kebu入侵的数量分别为FMQ-0.8至FMQ + 0.2，以及FMQ + 1.3至FMQ + 2.0。在岩石硫化物具有δ ³⁴小号_CDT范围从5.3到7.5 +‰为Erbutu侵入和从2.0到+ 4.5‰的克布侵入，比MORB地幔（δ的高得多的³⁴小号_CDT  = - 1.5至0.6‰）。的Erbutu和克布侵入的岩石具有δ ¹³下具有从-26.1至-20.4‰和- 26.4至-20.9‰，分别类似于有机碳在地壳（δ ¹³ C = -28至-20‰ ），但大部分比MORB地幔的降低（δ ¹³C = -7至-5‰）。这些可能表明向岩浆中添加了外部来源的硫（S）和有机碳，这将分别增加岩浆的S含量和降低S的溶解度，从而触发岩浆的硫化物饱和。值得注意的是，Erbutu侵入岩的硫化物饱和度主要与岩浆中外部来源的硫的添加有关，因为硫通常以低f O ₂岩浆中的S ^2-形式存在。既入侵有微量元素图案和ε_的Nd（t）值几乎相同于在相同的区域中的二叠Elitu火山岩，表明它们有可能遗传连锁。Elitu火山岩与（Gd / Yb）_N呈负相关MgO含量> 3.0 wt％的镁，这被解释为岩石的主要岩浆，可能在高压（例如0.8至2.0 GPa）下经历了石榴石的早期分离。在该区域计算出的地壳厚度约为56 km，相当于压力约为1.7 GPa。Erbutu和Kebu侵入岩的主要岩浆是由增厚的地壳下面的富集的SCLM部分熔融而产生的，并且可能富集了Ni，这对于安第斯式大陆汇聚边缘的经济的Ni-Cu硫化物矿化也至关重要。在CAOB中。