CAJ | 학술논문

似层状铬铁矿床长期以来被认为是岩浆分异成因，但近年来有学者提出其中个别产在蛇绿岩中。本文选择北京放马峪似层状铬铁矿床中纯橄岩、辉橄岩和辉石岩中不同类型的含铬尖晶石进行了电子探针分析。研究表明，岩浆早期的纯橄岩和辉橄岩中的铬尖晶石富铬（ Cr2 O3平均43.32％），而岩浆晚期辉石的结晶消耗了大量Cr3﹢，由于氧逸度的升高，在辉石岩的单斜辉石中出溶贫铬的铬磁铁矿（Cr2O3平均10.32％）和富铝尖晶石（Cr2O3平均15.77％）。与世界上不同类型铬尖晶石的矿物化学特征进行对比，可以认为放马峪铬铁矿床是产在阿拉斯加型岩体中的早期岩浆矿床，而与蛇绿岩无关。本文对放马峪铬铁矿床成因和成矿专属性的限定，为这类镁铁-超镁铁岩体的铬、铜镍、铂族元素的找矿勘查提供了依据。
사층상락철광상장기이래피인위시암장분이성인，단근년래유학자제출기중개별산재사록암중。본문선택북경방마욕사층상락철광상중순감암、휘감암화휘석암중불동류형적함락첨정석진행료전자탐침분석。연구표명，암장조기적순감암화휘감암중적락첨정석부락（ Cr2 O3평균43.32％），이암장만기휘석적결정소모료대량Cr3﹢，유우양일도적승고，재휘석암적단사휘석중출용빈락적락자철광（Cr2O3평균10.32％）화부려첨정석（Cr2O3평균15.77％）。여세계상불동류형락첨정석적광물화학특정진행대비，가이인위방마욕락철광상시산재아랍사가형암체중적조기암장광상，이여사록암무관。본문대방마욕락철광상성인화성광전속성적한정，위저류미철-초미철암체적락、동얼、박족원소적조광감사제공료의거。
Stratiform chromite deposits in China have long been considered to form by fractional crystallization of mafic magma. However,some researchers recently proposed that some chromite deposits are also hosted in ophiolite. In this study,Cr-spinels of the dunites,wehrlites and clinopyroxenites from the Fangmayu chromite deposit in Beijing are analyzed by EPMA. Results show that Cr-spinels of dunites and wehrlites at the early stage of magma differentiation are rich in Cr with an average Cr2 O3 content of 43. 32%. At the late stage of magma differentiation,the crystallization of clinopyroxenites consumed large amounts of Cr3﹢ and elevated the oxygen fugacity,leading to the Cr-rich magnetite and Al-rich spinel with average Cr2 O3 contents of 10. 32% and 15. 77%, respectively. By comparing with the chemical composition of different types of Cr-spinels from the world,the suggestion is that Fangmayu chromite deposit was a magmatic deposit hosted in Alaskan-type intrusion,and was not related to ophiolite. The constraints on the genesis and metallogenic specialization provide evidence for mineral prospecting of Cr,Cu-Ni and PGE deposits hosted in mafic-ultramafic intrusions.