新疆白鑫滩铜镍矿床矿物学、Sr-Nd同位素特征及其成矿过程探讨
发布时间：2018-11-11 11:33
【摘要】：白鑫滩铜镍矿床是近几年在东天山地区新发现的一个中型铜镍矿床,位于觉罗塔格构造岩浆带中段,对其开展深入研究有利于下一步的矿床勘查。本文在前人研究成果基础上,对白鑫滩矿床进行了较系统的橄榄石、辉石、斜长石和铬尖晶石矿物晶体化学和全岩Sr、Nd同位素的研究工作。结果表明白鑫滩矿床橄榄石Fo值为78.8~84.3,属贵橄榄石,Ni含量为299×10~(-6)~2483×10~(-6)。斜方辉石En为79.1~83.9,属古铜辉石;单斜辉石En为44.3~48.8,Wo为42.6~45.4,属透辉石-顽透辉石。斜长石An为60~83.9,主要为拉长石和培长石;铬尖晶石100Cr/(Cr+Al))为51~73.9。模拟计算表明白鑫滩矿床母岩浆MgO和FeO含量分别为9.30%和10.59%,Mg#值为0.61,是原始岩浆发生一定程度分离结晶的产物。母岩浆中橄榄石开始结晶温度为1258℃,约发生了7%的橄榄石分离结晶,结晶出的橄榄石与熔离出的硫化物的质量比介于50∶1~15∶1之间。斜方辉石开始结晶温度为1183℃,单斜辉石开始结晶温度为1143℃。白鑫滩矿床的(~(87)Sr/~(86)Sr)i=0.70278~0.70439,εNd(t)=+4.51~+5.92(t=278Ma),表明其源区为亏损地幔,但其富集程度略高于东天山地区其它典型矿床。Sr、Nd同位素模拟计算表明原生岩浆上升过程中经历了约5%~20%的地壳物质同化混染,橄榄石的分离结晶和地壳物质同化混染共同促进了岩浆中硫化物的熔离。
[Abstract]:The Baixintan copper-nickel deposit is a newly discovered middle-sized copper-nickel deposit in the East Tianshan area in recent years. It is located in the middle section of the Guolotag tectonic magmatic belt. Further study on the deposit is beneficial to the further exploration of the deposit. Based on the previous research results, a systematic study of the crystal chemistry of olivine, pyroxene, plagioclase and chromium-spinel minerals and Sr,Nd isotopes of the whole rock has been carried out in the Baixintan deposit. The results show that the Fo value of olivine in Baixintan deposit is 78.8 ~ 84.3, belonging to olivine, and the Ni content of olivine is 299 脳 10 ~ (-6) ~ 2483 脳 10 ~ (-6). The En of clinopyroxene is 79.1 / 83.9, which belongs to palaeopyroxene, and the En of clinopyroxene is 44.3 / 48.8Wo / 42.6 / 45.4, belonging to diopyroxene / dienstatite. The An of plagioclase is 60 ~ 83.9, which mainly consists of elongated stone and feldspar, and the 100Cr/ (Cr Al) of chrome spinel is 51 ~ 73.9. The results show that the contents of MgO and FeO in the parent magma of Xintan deposit are 9.30% and 10.59mg #, respectively, which are the products of some degree of separation and crystallization of the primitive magma. The initial crystallization temperature of olivine in the mother magma is 1258 鈩，
本文编号：2324717
[Abstract]:The Baixintan copper-nickel deposit is a newly discovered middle-sized copper-nickel deposit in the East Tianshan area in recent years. It is located in the middle section of the Guolotag tectonic magmatic belt. Further study on the deposit is beneficial to the further exploration of the deposit. Based on the previous research results, a systematic study of the crystal chemistry of olivine, pyroxene, plagioclase and chromium-spinel minerals and Sr,Nd isotopes of the whole rock has been carried out in the Baixintan deposit. The results show that the Fo value of olivine in Baixintan deposit is 78.8 ~ 84.3, belonging to olivine, and the Ni content of olivine is 299 脳 10 ~ (-6) ~ 2483 脳 10 ~ (-6). The En of clinopyroxene is 79.1 / 83.9, which belongs to palaeopyroxene, and the En of clinopyroxene is 44.3 / 48.8Wo / 42.6 / 45.4, belonging to diopyroxene / dienstatite. The An of plagioclase is 60 ~ 83.9, which mainly consists of elongated stone and feldspar, and the 100Cr/ (Cr Al) of chrome spinel is 51 ~ 73.9. The results show that the contents of MgO and FeO in the parent magma of Xintan deposit are 9.30% and 10.59mg #, respectively, which are the products of some degree of separation and crystallization of the primitive magma. The initial crystallization temperature of olivine in the mother magma is 1258 鈩，
本文编号：2324717
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