中文摘要：

嵩县南部大面积出露中元古界熊耳群鸡蛋坪组中酸性喷出岩，岩相学特征和主量元素组成表明它们为流纹岩、英安质流纹岩及安山岩．其岩石全碱（Na，04-K，0）含量除两个样品小于3．5％外，其它样品平均为5．32％；CaO含量平均为1．21％；占值一般为0．89～2．1，属钙碱性岩类．稀土元素配分模式以轻稀土强烈富集、弱正Ce异常和中等负Eu异常为特征．在火山岩不相容元素蛛网图上，所有的样品都具有相似的微量元素特征，富集Ba，Rb等高场强元素，亏损Nb，Sr等低场强元素，在Rb-（Y＋Nb）和Hf-Rb—Ta判别图解上，它们主要落在VAG和WPG范围内，成岩环境具有板内弧火山岩特征．

英文摘要：

Southern Song county mainly exposes Mesoproterozoic Erathem Xionger group Jidanping Fm interme- diate - acidic explosive rock. The characteristics of petrography and the composition of major elements show that they are rhyolite, dacite rhyolite and andesite. The data of all alkali content （ N%O ＋ K20） of the two samples is below 3.5% , the others are 5.32% ; the average of CaO is 1.21% ; the value of is commonly 0. 89-2.1, which belongs to Calcium alkaline rock types. The characteristics of rare earth element distribution are the enrichment of light rare earth, the weak positive anomaly of Ce and medium negative anomaly of Eu. In the spider diagram of a volcanic rock incompatible element, all the samples have the similar rare earth ele- ment characteristics and enrich the high field intensity element Ba and Rb and loss the low field intensity ele- ment Nb and Sr. In the discriminant figure of Rb-（Y ＋ Nb） and Hf-Rb-Ta, they are mainly located in VAG and WPG, the characteristics of diagenetic environment is intraplate arc ,Jolcanic rocks.