投稿时间：2015-09-17
修订日期：2016-03-24
网络发布日期：2016-10-29
中文摘要:对金堆城钼矿区辉绿岩脉的岩石学和地球化学的详细研究表明，该区辉绿岩均遭受到不同程度的蚀变，为拉斑系列岩石，其主量元素以中等w（TiO2）（1.47%~2.16%）、中等w（MgO）（3.47%~6.58%）、Mg#为26.99~40.46，w（K2O）变化较大（0.05%~3.16%）为特征，可能与蚀变有关，贫w（P2O5）（0.36%~0.58%）、MgO与主要组分的相关性表明，岩浆早期出现过轻微的橄榄石、斜方辉石及铬铁矿、钛铁矿结晶分异；稀土元素总量相对较高，轻重稀土元素分馏显著（（La/Yb）N=7.5~12.4），δEu为0.7~1.0，出现Eu的弱负异常。金堆城钼矿区的辉绿岩脉属于大陆板内拉斑玄武岩，形成过程中受到地壳物质的混染。
Abstract:A study of petrology and element geochemistry shows that Jinduicheng diabase dyke has suffered from different degrees of alteration, and belongs to the tholelite series. SiO2 values of the Jinduicheng diabase dyke vary in the range of 48.13%~57.74%; in addition, it has high MgO (3.47%~6.58%), its Mg# values are 26.99~40.46, its TiO2 values vary in the range of 1.47%~2.16%, its K2O values vary considerably (0.05%~3.16%), and it has poor P2O5 (0.36%~0.58%). Four of the samples show Na2O > K2O, and the other samples show Na2O < K2O. The correlation between MgO and the main components indicates that olivine, orthopyroxene, chromite, and ilmenite experienced slight crystallization differentiation at the early magma stage. ΣREE values are 169.4×10-6~450.78×10-6, REE distribution patterns are of "V" type, there exists a weak negative Eu anomaly, and δEu values are 0.7~1.0. Light and heavy rare earth element fractionation is remarkable ((La/Yb)N=7.5~12.4, LREE/HREE=2.7~4.22). They are enriched in K, Rb, U, Th and Sr, and strongly depleted in Ba, P and Ti. The characteristics of the high field-strength elements (HFSE) suggests that the diabase dyke belongs to the continental intraplate tholeiite, but was contaminated by crustal material in the formation process.
文章编号：
中图分类号：P618.65
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基金项目:本文得到中央级公益性科研院所基本科研业务专项资金“岩浆热液演化的包裹体证据-东秦岭金堆城斑岩钼矿床熔融包裹体和熔融-流体包裹体研究（编号：YK1503）”、山西中条山铜矿峪铜矿矿床地质特征及成因研究（编号：K1408）、中国地质调查项目“中国铜多金属成矿规律、矿床模型和找矿方项研究（编号：12120113093600）”和中国地质调查项目“重要矿种关键问题调查与矿产地质专题填图试点（编号：DD20160124）”的联合资助
引用文本：
李洪英,杨磊,柯昌辉,王修缘,刘素彤.2016.东秦岭金堆城钼矿床辉绿岩地球化学特征及其地质意义[J].矿床地质,35(5):1099~1114LI HongYing,YANG Lei,KE ChangHui,WANG XiuYuan,LIU SuTong.2016.Geochemistry of diabase dyke in Jinduicheng Mo deposit, Eastern Qinling and its geological significance[J].Mineral Deposits35(5):1099~1114
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