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熊耳群火山岩为古相火山岩,普遍经受了变质作用,但变质程度浅且不均匀,其结构一般保存完好,时可见岩浆矿物残存、其原岩为一套基性—酸性熔岩组成的双峰式火山岩。本区熔岩属豫西熊耳群火山岩之一部分,相对豫西其它地区的同类熔岩变质程度更浅一些,经测定其斜长石成分以钠长石为主,次为更长石及更中长石,An=40以上的斜长石少见。斜长石之有序度多数为0.6—1、少数为0.4—0.6。据费氏台测定,熔岩中钾长石为中正微长石及低微斜长石,据Ⅹ衍射资料,用三峰法求出钾长石部分为正长晶胞碱性长石,部分为异常晶胞碱性长石,其结构状态及存在结构状态以最大微斜长石为主,少数为中间微斜长石及存在于两者之间的过渡状态的微斜长石。变质作用是通过严格的整合假像替换作用进行的,变质程度未超过绿片岩相。现用某些粘片树胶折光率,其值小於1.540,且折光率高低随温度而异,因此,在用费氏台测定斜长石,采用树胶对比法确定消光角NP’∧(010)的符号时,务必在同一温度下对粘片用的树胶折光率进行测定,这样,才能准确鉴定斜长石的种类。
Xiong’er Group volcanic rocks are ancient volcanic rocks that have undergone metamorphism generally but are slightly altered and inhomogeneous in texture. Their structures are generally well preserved and their remnants of magmatic minerals are visible. The original rock is a bimodal type of basic-acidic lava Volcanic rocks. The lava in this area is a part of volcanic rocks of the Xiong’er Group in the west of Henan Province. The lavas of the same type are lager in comparison with the lavas of the same type in other areas of the western Henan Province. The plagioclase is dominated by albite, followed by feldspar and more , An = 40 or more plagioclase rare. Plagioclase order degree of the majority of 0.6-1, a small number of 0.4-0.6. According to Freescale’s determination, the lavas in the K-feldspar are feldspar and low plagioclase feldspar, according to X-ray diffraction data obtained by the three-peak method for the feldspar potassium feldspar is a positive long cell alkaline feldspar, part of the abnormal crystal Alkaline feldspar, the structure of the state and the existence of the structural state of the largest micro-plagioclase feldspar, a small number of intermediate plagioclase feldspar and exist in between the transitional state between the micro plagioclase feldspar. Metamorphism is through rigorous integration of artifact replacement, metamorphism does not exceed the greenstone facies. The refractive index of certain adhesive chip gums is less than 1.540, and the refractive index varies with temperature. Therefore, when plagioclase is determined by Freescale’s, the extinction angle NP’∧ (010) Symbol, it is essential to measure the refractive index of the gum for the adhesive sheet at the same temperature, in order to accurately identify the type of plagioclase.