论文部分内容阅读
与大多数含铜斑岩产于陆相火山岩区不同，甘肃公婆泉含铜斑岩（即英安斑岩和花岗闪长斑岩）在空间和成因上与中－晚志留世浅海相火山岩系关系密切。这两类含铜斑岩均侵入于石英粗面岩中，斑晶矿物成分、斜长石牌号、岩石化学成分、铁族及成矿元素的丰度等相近，均属钙碱性岩系（里特曼指数为１．６９～２．７５），具富Ｋ（Ｋ２Ｏ为２．８０％～４．７７％）、低Ａｌ（Ａｌ２Ｏ３为１４．４６％～１６．０１％）、低Ｃａ（ＣａＯ为２．４９％～４．６３％）及成矿元素含量较高的特点。与花岗闪长斑岩相比较，英安斑岩的斑晶含量较低而晶屑含量较高、钾化蚀变较强烈、Ｆｅ２Ｏ３／ＦｅＯ值和Ｋ２Ｏ含量较高、ＣａＯ含量较低。两类斑岩是同源岩浆的浅成－超浅成侵入体，英安斑岩的侵位深度相对较浅。
Unlike most copper-bearing porphyries produced in continental volcanic rocks, the Gypsum-bearing copper-bearing porphyry (ie, the amphibolite and granodiorite porphyry) in Gansu Province is spatially and genetically related to the Middle-Late Silurian shallow marine Volcanic rocks are closely related. Both types of copper-bearing porphyries intrude into quartz facies, which are similar to calc-alkaline rocks (Porphyrites, plagioclase, chemical compositions of rocks, abundances of iron and mineral elements) The Rittman index is 1.69 ~ 2.75) with K (K2O 2.80% ~ 4.77%), low Al (Al2O3 14.46% ~ 16.01%) and low Ca CaO is 2.49% ~ 4.63%) and higher metallogenic elements. Compared with the granodiorite porphyry, the porphyrite content of the Yingan porphyry is lower and its crystal content is higher, the potassium alteration is stronger, the Fe2O3 / FeO value and K2O content are higher, and the CaO content is lower. Two types of porphyry are the magmatic shallow-super-shallow intrusive intrusive porphyry emplacement depth is relatively shallow.