凉山州南红玛瑙致色元素与成矿环境的研究

发布时间：2018-06-03 04:53

本文选题：南红玛瑙 + 致色元素　；参考：《成都理工大学》2015年硕士论文

【摘要】：南红玛瑙是一种隐晶质矿物集合体,属于玛瑙的一种。自然界中天然产出的红色宝玉石非常稀有,像南红玛瑙这样拥有鲜艳的红色,又同时具备油润光泽的玉石可谓是目前市场上独一无二的。此独特性使得南红玛瑙成为收藏家们追逐的对象,收藏保值的最佳选择。本文结合了前人对南红玛瑙研究的成果和野外矿区实地考察,介绍了南红玛瑙的市场情况、产地分布及分类;并通过偏光显微镜观察、红外光谱仪测试、电子探针数据等实验方法对南红玛瑙的结构构造、化学成分进行分析;使用X射线荧光光谱仪和显微拉曼光谱仪对南红玛瑙的致色元素和致色矿物进行了分析;结合矿区的地质条件和历史构造运动简单的分析了南红玛瑙的成矿环境及成因。近年来,南红玛瑙在市场上迅速蹿红,价格不断上涨,原石供不应求,好料更是难得。南红玛瑙主要有两个产地,云南保山和四川凉山,云南保山的产量不大,并且多裂,而凉山产出的南红玛瑙则相对较完整。凉山南红玛瑙按颜色主要分为柿子红、玫瑰红、樱桃红、红白料、冰飘、缠丝等几大类。通过电子探针数据测试出SiO2的含量高达95%以上,其它含量较少,说明南红玛瑙的主要矿物成分为石英,其成分较为纯净,杂质较少。通过显微镜下观察南红玛瑙在单偏光镜下为无色,在正交偏光镜下观察为隐晶质结构,可分为纤维状结构和粒状结构,可见形态为纤维按生长环带定向排列或长纤维、短纤维和细粒状定向排列,几乎不可见包裹体。通过红外光谱仪测试南红玛瑙在2000~2800cm-1范围内有Si-O键的吸收,在3800cm-1有Si-O键的双倍吸收,说明南红玛瑙的结构是隐晶质玉髓向显晶质石英过渡的一个过渡结构。通过对南红玛瑙的粉末进行XRF测试,测试结果为南红玛瑙中除主要化学成分SiO2以外,还有Fe2O3、Al2O3、MnO、Cr2O3、CaO、MgO、TiO2、等化学成分,Fe2O3的含量为0.61%~1.26%,MnO的含量为0.05%~0.14%,Cr2O3的含量为0~0.2%。随着Fe2O3的含量升高,南红玛瑙的红色随之越浓,说明其主要致色元素为Fe离子,其致色成分为Fe2O3,而Mn离子和Cr离子的含量对南红玛瑙的成色也有所影响,初步判断为MnO含量越高,南红玛瑙的红就越偏玫瑰色,Cr2O3含量越高,南红玛瑙的红就越鲜艳;部分透明度较好的南红玛瑙肉眼可见颜色是由红色的细小颗粒聚集而成,经显微拉曼光谱仪对此红色颗粒进行测试,谱图显示在290 cm-1、610 cm-1、1320cm-1有明显峰值,证明此颗粒为赤铁矿。因此,可以说明南红玛瑙中主要致色元素Fe离子是以赤铁矿的形式存在的。南红玛瑙为杂质致色,其赤铁矿颗粒的分布导致的南红玛瑙颜色的分布,显微镜下发现赤铁矿颗粒在南红玛瑙中的分布呈三种形态,第一种以沿南红玛瑙本身生长环带分布的微晶—显微隐晶微粒出现;第二种以浸染状、弥散状或星云状分布的隐晶微粒出现;第三种是沿裂隙呈细脉状贯入,并按原生长环带扩散分布。推测第一种为原生致色,第二种和第三种为次生致色,致色原因与南红玛瑙成矿环境有关。根据该区野外实地考察以及对南红玛瑙原石和围岩的分析,推断南红玛瑙矿床属于岩浆热液型矿床。形成时代为二叠纪晚期,其物源为玄武岩岩浆喷发作用形成的热液。成矿过程分为原生成矿和次生成矿,原生成矿为岩浆热液在玄武岩气孔中进行结晶成矿,在高温富氧环境下使Fe2+氧化为Fe3+,进而在南红玛瑙中形成赤铁矿颗粒,此颗粒使南红玛瑙呈红色,颗粒的成色与成矿过程保持一致,由于岩浆多次喷溢导致了成矿环境的改变,使得南红玛瑙形成了圈层状,高温和高压使南红玛瑙纤维化;次生成矿主要发生在二叠系晚期和三叠系早期,由于玄武岩的风化剥蚀后,使得南红玛瑙赋存于以凝灰岩为主的火山碎屑岩中,其次生矿床赋存于宣威组底部的底砾岩和东川组底部的残积层。与成矿作用有直接关系的是偏基性凝灰岩和以凝灰岩为主的火山碎屑岩。二叠系峨眉山玄武岩组与宣威组之间所夹的凝灰质火山碎屑岩直接控制着南红玛瑙矿产的产出与分布。
[Abstract]:Agate is a kind of crypto mineral aggregate, a kind of agate. The natural red gem stone is very rare in nature. It has bright red like South red agate, and the jade with oil gloss is unique in the market. This unique feature makes the agate chased by the collectors. In this paper, the market situation, distribution and classification of the agate in South Red Agate were introduced in this paper, and the structural structure and chemical composition of the agate in South Red Agate by the polarizing microscope observation, the infrared spectrometer test and the electronic probe data were introduced. The X ray fluorescence spectrometer and the micro Raman spectrometer were used to analyze the chromatic elements and chromatic minerals of agate in south red agate, and the metallogenic environment and causes of the agate were analyzed with the geological conditions and historical tectonic movement of the mining area. There are two main origins of the red agate, Baoshan and Liangshan in Yunnan, Liangshan in Sichuan, and Baoshan in Yunnan, which are less productive and more cracked, and the southern red agate of Liangshan is relatively complete. The red agate of Liangshan is divided mainly into persimmon red, rose red, cherry red, red and white material, ice floating, filament winding and so on. The content of SiO2 is more than 95%, and the other content is less. It shows that the main mineral component of agate is quartz, and its composition is pure and the impurity is less. The granular structure, the visible form of fiber according to the directional arrangement of growth ring or long fiber, short fiber and fine-grained orientation, almost invisible inclusions. Through the infrared spectrometer, the agate absorption of Si-O bond in the range of 2000~2800cm-1 and the double absorption of the Si-O bond in 3800cm-1 indicate that the structure of the agate is a cryptocrystalline chalcedony. A transition structure to crystalloid quartz. Through the XRF test of the powder of red agate, the results show that besides the main chemical composition SiO2 in the agate, there are Fe2O3, Al2O3, MnO, Cr2O3, CaO, MgO, TiO2, and so on. The content of Fe2O3 is 1.26%. As the content of 2O3 increases, the red agate of South Red Agate is thicker, indicating that its main chromatic element is Fe ion, and its color composition is Fe2O3, while the content of Mn and Cr ions also affects the color of agate in south red. The higher the MnO content, the more red agate red in south red agate, the higher the Cr2O3 content, the more red agate of South red. Bright colourful; the visible color of a partially transparent south red agate is visible from the red fine particles. The red particles are tested by the microraman spectrometer. The spectra show that there is a significant peak at 290 cm-1610 cm-11320cm-1, which proves that the particle is hematite. Therefore, the main chromatic element in the agate is Fe. The son is in the form of hematite. Nanhong agate is colored by impurities and the distribution of hematite particles leads to the distribution of the red agate color. Under the microscope, it is found that the distribution of hematite particles in agate is three forms. The first kind is microcrystalline microcrystalline particles distributed along the ring belt of the agate itself; second The appearance of cryptic particles in the form of disseminated, diffuse or nebulous distribution; the third is in a fine vein and spread along the fissure, and is distributed according to the original growth ring. The first is primary color, second and third are secondary, and the cause of color is related to the annulus of Nanhong agate. According to field field investigation and south red in this area The analysis of agate rock and surrounding rock concludes that the South Red Agate deposit belongs to the magmatic hydrothermal deposit. The formation age is late Permian, and its source is the hydrothermal fluid of basalt magma eruption. The metallogenic process is divided into primary ore and secondary ore-forming ore. The original ore deposit is magmatic hydrothermal solution in the pores of basaltic rock, and in high temperature and oxygen enrichment. Under the environment, Fe2+ is oxidized to Fe3+, and then red agate particles are formed in south red agate. This particle makes the red agate red, the color of the particles is consistent with the metallogenic process. Because of the multiple spilling of the magma, the mineralization environment is changed, and the agate is formed in the ring layer, and the agate is fibrosis in south red agate. It occurs mainly in the Late Permian and Early Triassic period. Due to the weathering and erosion of the basalt, the Nagan agate occurs in the volcanic clastic rocks dominated by the tuff. The secondary deposits occur in the bottom conglomerate at the bottom of the Xuanwei formation and the residual deposits at the bottom of the Dongchuan formation. The volcanic clastic rocks dominated by rock. The tuffaceous pyroclastic rocks between the Permian Mount Emei basalt group and Xuanwei group directly control the output and distribution of Nagan agate minerals.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P619.283

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