摘要
汤家坪钼矿床是2006年探明的一处大型斑岩型钼矿床,前人用常规地质方法对该矿区基础地质工作和成矿规律研究已比较系统和完整,认为汤家坪钼矿床属于深源浅成斑岩型钼矿床,汤家坪花岗斑岩体为矿区钼矿的成矿母岩;但是没有从矿物学角度来应证这些成矿规律。本文从矿物学角度,采用分离单矿物进行化学分析、X射线衍射(XRD)及岩矿鉴定等技术,对汤家坪钼矿区的辉钼矿、黄铁矿、石英、长石4种矿物标型特征(化学组成、微量元素、晶体结构、晶胞参数、结构状态等)进行研究。结果表明:1该矿区辉钼矿全部是2H型多型变体,且成分中Re含量很低;辉钼矿的δ34S值为3.0‰,硫同位素变化范围小,接近于陨石硫,具深源硫的特点,硫来源于花岗斑岩。2黄铁矿微量元素以富含Mo、Co、Cu,贫Ni、Pb、Zn为标型特征,另外Au、Ag含量低,S/Se大于250000,与前人"S/Se大于250000~500000的地区不可能找到金矿"的结论相符。3石英富含Mo;成矿期石英脉中δ18O降低,表明成矿晚期有少量大气降水参与热液蚀变成矿。4长石富含Mo;轻稀土(La^Nd)含量大于中稀土(Sm^Ho)和重稀土(Er^Y)含量;钾长石的有序度、三斜度以及结构参数的值均较高,结构温度较低,表明该矿区钾长石为低温状态下的三斜对称的微斜长石,是热液作用的产物,岩体钾长石化对钼矿化最为有利。本研究应证了汤家坪钼矿床属于深源浅成斑岩型钼矿床,对于总结斑岩型钼矿成矿规律、找矿标志有重要意义。
The Tangjiaping molybdenum deposit,discovered in 2006,is a large-scale porphyry molybdenum deposit.The studies of its basic geological work and metallogenic regularity have been completed by previous researchers with conventional geological methods.The results showed that the Tangjiaping molybdenum deposit belongs to the plutonic hypabyssal porphyry molybdenum deposit and the Tangjiaping granodiorite porphyry molybdenum mineralization acts as a mother rock mining area.However,there is no proof that the metallogenic regularity is from the perspective of mineralogy.From the mineralogy angle four kinds of typomorphic characteristics（chemical composition,trace elements,crystal structure,lattice parameters,structure etc.） of molybdenite,pyrite,quartz,and feldspar from the Tangjiaping molybdenum mine were studied using the separation of single mineral to chemical analysis,X-ray Diffraction and rock mineral identification technology.The results are：1 the mining area of molybdenite is 2H type,and the content of Re component is very low; the δ34S of molybdenite values is 3.0‰; sulfur isotopic changes in a small range close to the meteorite sulfur with the characteristics of deep source sulfur,indicating that the sulphur is derived from the granite porphyry.2 pyrite is rich in trace elements Mo,Co,Cu,poor Ni,Pb,Zn,in addition,low content of Ag and Au,S / Se is greater than 250000,which is consistent with the ‘S / Se more than 250000- 500000 area could not find gold’conclusion.3 quartz is rich in Mo.δ18O in mineralization quartz veins are lower,showing a small amount of precipitation appeared in the hydrothermal alteration during the later mineralization.4 feldspar is rich in Mo.Light rare earth（La-Nd） content is higher than that of rare earth（Sm-Ho） content and heavy rare earth（Er-Y） content.Potassium feldspar degree of ordering,triclinic and structure parameter values were higher.Potassium feldspar structure at low temperature,shows that the potassium feldspar in this area is triclinic symmetry microcline at low temperature conditions,and it is the product of hydrothermal activity; rock potash feldspathization characteristics of molybdenum mineralization is the most favorable.The Tangjiaping molybdenum deposit therefore belongs to the plutonic hypabyssal porphyry molybdenum deposit,and this paper has important significance for the summarization of porphyry type molybdenum ore metallogenic regularity and prospecting marks.
出处
《岩矿测试》
CAS
CSCD
北大核心
2015年第1期82-90,共9页
Rock and Mineral Analysis
基金
河南省科技厅河南省重点实验室专项经费项目"大别山成矿带钼矿区矿物组合及标型矿物空间分布特征与成矿规律关系研究"(122300413221)
关键词
汤家坪钼矿
标型特征
晶胞参数
结构状态
化学分析
X射线衍射法
岩矿鉴定
Tangjiaping molybdenum
typomorphic characteristics
lattice parameters
structure state
chemical analysis
X-ray Diffraction
rock mineral identification
作者简介
周姣花，高级工程师，主要从事岩矿鉴定、工艺矿物学、成因矿物学研究工作。E-mail：1071732967@qq.com
