CAJ | 학술논문

提橄榄石通常是玄武质岩浆最早结晶出的矿物之一，其化学成分可以很好地反演母岩浆成分、岩浆结晶分异、硫化物熔离等成岩及成矿信息。本文以土墩镁铁质-超镁铁质杂岩体为研究对象，采用电子探针对岩体中的橄榄石矿物颗粒进行化学成分测试。利用橄榄石的Fo值和其中Ni含量，计算得到土墩杂岩体母岩浆中MgO含量约为12.95%，是一种富镁的玄武质岩浆。同时，定量模拟结果表明，土墩杂岩体母岩浆中硫化物熔离几乎与橄榄石结晶作用同时进行，早阶段由橄榄石结晶（分离结晶程度约2%）而导致硫化物的熔离程度为0.2%。随后，橄榄石分离结晶程度在6%~7%时，硫化物熔体的熔离程度仅为0.01%。这些表明土墩杂岩体发生过一定程度的硫化物熔离，但成矿前景不是很好。此外，部分数据显示出Ni-Fo的负相关性，表明少许富铁橄榄石和晶间硫化物熔浆发生了Fe-Ni物质交换反应，这对橄榄石的成分有重要影响。
제감람석통상시현무질암장최조결정출적광물지일，기화학성분가이흔호지반연모암장성분、암장결정분이、류화물용리등성암급성광신식。본문이토돈미철질-초미철질잡암체위연구대상，채용전자탐침대암체중적감람석광물과립진행화학성분측시。이용감람석적Fo치화기중Ni함량，계산득도토돈잡암체모암장중MgO함량약위12.95%，시일충부미적현무질암장。동시，정량모의결과표명，토돈잡암체모암장중류화물용리궤호여감람석결정작용동시진행，조계단유감람석결정（분리결정정도약2%）이도치류화물적용리정도위0.2%。수후，감람석분리결정정도재6%~7%시，류화물용체적용리정도부위0.01%。저사표명토돈잡암체발생과일정정도적류화물용리，단성광전경불시흔호。차외，부분수거현시출Ni-Fo적부상관성，표명소허부철감람석화정간류화물용장발생료Fe-Ni물질교환반응，저대감람석적성분유중요영향。
Olivine is one of the earliest crystallization minerals from basaltic magma, and its composition can directly give the metallogenesis information on parent magma composition, processes of magmatic fractional crystallization, and sulfide segregation degree. In this study, the authors selected the Tudun mafic-ultramafic complex to conduct electron microprobe analysis of olivine minerals. According to the Fo and Ni values of olivine, he MgO content of parent magma, which contains the highest Fo olivine, was estimated to be 12.95%, indicating that the parent magma of the Tudun complex is a high-MgO basalt. The modeling results show that sulfide segregation and fractional crystallization almost took place at the same time. A slight sulfide segregation (about 0.2%) occurred during the early stage (0-2%) of olivine fractional crystallization process, and less sulfide segregation (about 0.01%) occurred during the later stage (6%-7%), which suggests that the metallogenic potential of the Tudun complex is limited. In addition, some data implying the negative relationship between Fo and Ni indicate that Fe-Ni exchange reaction happened between Fe-rich olivine and trapped sulfide liquid, which caused remarkable differences in olivine composition.