93 / 2019-10-10 17:10:53

泰顺石矿物组成及其对成因的启示（新）

泰顺石,雕刻石,叶蜡石,硬水铝石

摘要：泰顺石是产于浙江省温州市泰顺县龟湖镇的叶腊石型雕刻石，作为第五大雕刻石占据着一定的市场份额。本文利用10倍放大镜、偏光显微镜、X射线粉晶衍射仪、拉曼光谱仪对泰顺石的矿物组成进行观察,并分析其成因意义。实验及分析结果表明，泰顺石样品主要组成矿物为叶蜡石（1Tc型为主），另有少量的石英、硬水铝石、高岭石、伊利石、赤铁矿、刚玉等。岩相学分析表明，泰顺石中叶蜡石根据成因可分为热液交代型和热液充填型两类。热液交代型叶腊石表现为叶腊石交代围岩中长石和硬水铝石形成交代残余结构和交代假象结构；热液充填型叶腊石表现为叶腊石后期充填于裂隙中。岩相学观察结果为泰顺石中叶腊石的形成提供了直接的证据。硬水铝石和刚玉为叶腊石形成过程中共生矿物，在泰顺石中分别表现为石钉和蓝钉。不同泰顺石样品中矿物组合直接或间接记录了泰顺石成矿过程中热液交代流纹质晶屑凝灰岩的围岩蚀变过程，如叶蜡石化、硬水铝石化等。红色泰顺石中赤铁矿的存在可能指示了成矿后期向氧化环境发生了转变。根据实验岩石学的结果，本次研究的泰顺石样品的矿物组合特征指示了泰顺石主要形成于温度约为260-394±10℃的环境中。
关键字：泰顺石；雕刻石；叶蜡石；硬水铝石
Abstract: The Taishunshi is a kind of pyrophyllite-type carving stone from Guihu town, Taishun county, Hangzhou, Zhejiang Province. The Taishunshi as the fifth largest carving stone has occupied a certain market share. Methods including 10× magnifying, optical microscope, X-ray diffraction (XRD), and laser Ramam spectroscopy (LRM) were employed to determine the mineral component of the Taishunshi samples and analyze its genetic significance. The results show that the main mineral component of samples is pyrophyllite (1Tc type). Minor quartz, diaspore, kaolinite, illite, hematite and corundum are also detected. Petrographic observation shows that pyrophyllite in the Taishunshi can be divided into two types which are hydrothermal metasomatic type and hydrothermal filling type. Pyrophyllite which is hydrothermal metasomatic type alters feldspar and diaspore in the wall rock forming metasomatic relict texture and metasomatic pseudomorphic texture. Pyrophyllite which is hydrothermal filling type fills the cracks in the later mineralizing process. Petrographic observation results provides direct evidence to the formation of the pyrophyllite. Diaspore and corundum which exist as paragenetic minerals during the mineralizing process of pyrophyllite show as stone nails and blue nails in the Taishunshi, respectively. The different mineral combination characteristics of the Taishunshi samples directly or indirectly record the metasomatism between hydrothermal solution and rhyolitic crystal tuff such as pyrophyllitization, diasporization, etc. The hematite in the red Taishunshi may indicate the change toward oxidization environment in the later mineralizing process. According to the results of experimental petrography, the mineral combination characteristics of the samples in this study indicate that Taishunshi should be mainly formed in an environment at a temperature ranging from 260-394±10℃.
Key words：Taishunshi; carving stone; pyrophyllite; diaspore