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位于青海省拉脊山南邻的化隆地区,发育多个规模相对较小的基性-超基性岩杂岩体,亦是南祁连山一条非常重要的成矿岩带,其内产出与该类岩体密切相关的裕龙沟、拉水峡、亚曲等中小型岩浆铜镍矿床。通过化隆地区小型侵入体的地质特征及地球化学综合研究,联系已有研究成果及其相关其他地质信息,发现化隆地区含铜镍矿岩体属铁质系列的基性-超基性杂岩体,表现为Nb、Ta、Ti的亏损,所有岩石均属于钙碱性系列,且轻稀土(LREE)和大离子亲石元素(LILE)相对富集,适度亏损高场强元素。矿石同位素研究揭示其原始岩浆在经历结晶分异后,又遭受了地壳混染作用,以及富Si地壳物质的加入,产生硫化物的熔离作用而成矿。结合区域构造演化过程与成矿认识,认为南祁连化隆地区的成岩成矿可能与形成时的俯冲相关的地质环境密切相关。
Located in the Hualong area adjacent to Lajishan Mountain in Qinghai Province, a number of relatively small-scale basic-ultramafic complex rock bodies are developed. It is also a very important metallogenic rock belt in the southern Qilian Mountains. Rock mass closely related Yulonggou, pull water gorge, Asia Qu and other small and medium-sized magmatic copper-nickel deposits. Through the comprehensive study of the geologic features and geochemistry of the small intrusions in Hualong area, it is found that the copper-bearing nickel ores in Hualong area are basic-ultrabasic miscellaneous in the iron series The rocks show the depletion of Nb, Ta and Ti. All the rocks belong to the calc-alkaline series, and the LREE and LILE are relatively enriched, and the high field strength elements are moderately depleted. Ore isotopic studies reveal that the original magma underwent crustal contamination after being crystallized, as well as the enrichment of Si-rich crustal materials and the formation of sulfide mineralization. Combined with regional tectonic evolution and metallogenesis, it is concluded that the diagenesis and mineralization of Hualong area in South Qilian may be closely related to the subduction-related geologic environment during the formation.