A study of moissanites in the serpentinite from south Dabie Mountain
-
摘要:
在大别山南部亭子岭、古山、虎形等蛇纹岩中发现碳硅石，粒径0.02~0.08mm，少数可达0.1~0.17mm，晶体有一轴晶（+）和二轴晶（+）（2V=37°），后者较发育，有较明显的二轴晶化。拉幔光谱峰值稳定，主峰788~789cm-1次峰968~972cm-1，弱峰767~784cm-1，个别样品产生较大偏移，主峰776.85cm-1，次峰964.82cm-1，可能为因其他微量元素的加入，结构发生改变所致。能谱分析显示，碳硅石混入较多杂质，其中最明显的O、Fe、Ca、K、Ni、Ti、S、Cl、Na等元素可能对结构产生一定的影响。从而也揭示了早期结晶的温度较高，杂质也较多。此外，碳硅石中见有流体包裹体，成分为CH4、C2H6、C3H8、C6H6、H2O等，产生碳硅石的蛇纹岩为大陆幔源岩石在上侵过程中，高温下差异性应变形成二轴晶化。根据实验资料，SiC形成温度为1600℃以上，压力大于等于6.0Gpa，应为在下地壳上地幔软流圈极端还原条件下产生的。
Abstract:Moissanites were found in serpentinites from Tinziling, Gushan and Huxi areas in south Dabie Mountain. The sizes of grains are mainly 0.02~0.08mm and subordinately 0.1~0.17mm. The crystals are uniaxial (+) and biaxial (+), 2V=370° with the biaxial crystals being dominant, showing obvious biaxiality.The Raman shifts of moissanites in the section are stable:a primary peak of 788~789cm-1, a secondary peak of 986~972cm-1, and a weak peak of 767~784cm-1. The mixture of Al, O in moissanites may cause change in texture of moissanites, and even cause comparatively larger deviation in Raman spectral analysis: a primary peak of 776.85cm-1, and a secondary peak of 964.82cm-1. The energy spectral analysis shows that the moissanites were mixed with a lot of other elements, such as O, Fe, Ca, K, Ni, Ti, S, Cl and Na. All of these elements may affect its texture. It is also shown that at the early stage it crystallized at relatively high temperature and had relatively abundant mixed elements. Besides, there exist fluid inclusions in moissanates, whose components include CH4, C2H6, C3H8, C6H6, H2O, etc. The moissanite-bearing serpentinite is a continent mantle rock; when it intruded upward, the biaxial crystal of moissanite was formed under the condition of high temperature and different stresses. According to experimental data, SiC was formed at the temperature >1600℃ and under the pressure≥6.0GPa. Therefore the moissanites here should have been produced under extremely low reduction condition, situated in asthenosphere of the upper mantle or the lower earth crust.
-
Key words:
- fluid inclusion /
- mineralogy /
- moissanites /
- serpentinite /
- southern Dabie Mountain
-
-
图 图版Ⅰ a~i.亭子岭、古山、虎形蛇纹岩薄片中碳硅石及磷灰石；a.一轴晶（+）；b.一轴晶（+）；c.二轴晶（+）；d.二轴晶（+）；e.二轴晶（+）；f.二轴晶（+）；g.一轴晶（+）；h.一轴晶（+）；i.一轴晶（+）
图 图版Ⅱ PlateⅡ a.碳硅石，板状，0.12mm×0.4mm, 具二相包裹体，浑圆状、圆状、三角状、板状，孤立，负晶形，大者5~10μm, 长柱状为碳硅石包体，40×单偏光；b.碳硅石，三方单锥，0.2mm×0.22mm, 20×单偏光；c.碳硅石，具环带构造，0.15mm×0.12mm, 中心为绿色，边缘为暗绿色-黑色，包裹体沿环带分布，40×单偏光；d.碳硅石，板状，0.15mm×0.3mm, 淡绿色，具二相包裹体及自然硅包体（边部黑色板状体），包裹体大者达2.5~5μm, 40×单偏光；e.碳硅石，环带构造，0.1mm×0.12mm, 复三方单锥，中心暗绿色、边缘黑色，40×单偏光；f.碳硅石，无色，六边形，0.2mm×0.23mm, 六方单锥？40×单偏光
图 图版Ⅲ PlateⅢ a.S-01，气相；b.S-02液相；c.S-03，气相；d.S-04，液相；e.S-05，气相；f.S-4-2，液相；g.Sp-1液相；h.S-08-1气相，S-08-2，液相；i.S-09-1，气相，S-09-2液相，其中a、b, c、d, e、f, h、i分别为同一包裹体
表 1 董家山蛇纹岩天然碳硅石X光衍射分析结果
Table 1. XRD results of moissanite from Dongjiashan serpentinito
样品号 N16 N17 N19 N56 N21 空间群 P6(3) mc P6(3) mc P6(3) mc P6(3) mc R (3) mc 晶胞参数 A=3.12(5)Å α=3.049(11)Å α=3.08(5)Å α=3.08(4)Å α=3.054(5)Å Dimensions C=15.36(5)Å C=14.99(11)Å C=15.13(5)Å C=15.09(4)Å C=37.46(13)Å 晶系 hexagonal hexagonal hexagonal hexagonal rhombohedral Z（分子数/单位） 6 6 6 6 15 多型（体） α-6H α-6H α-6H α-6H α-15R 
下载: 导出CSV
表 2 碳硅石能谱分析结果
Table 2. Energy spectra analytical results of moissanite
序号 样号 重量/百分比 C O Si Mg Al K Ca Fe Cr Ni S Cl Ti Na 总量 1 1-1 含量% 31.15 68.75 100 原子系数 1 1 2 2 1-3 含量% 26.31 61.91 11.19 0.39 0.19 100 原子系数 0.9 1 0.09 0.003 0.001 2 3 1-2 含量% 33.52 66.48 100 原子系数 0.99 1 2 4 1-4 含量% 27.92 52.43 19.32 0.33 100 原子系数 1 0.84 0.15 0.002 2 5 4-1 含量% 34.48 65.52 100 原子系数 1 0.99 2 6 5-1 含量% 34.13 65.87 100 原子系数 1 1.01 2 7 5-5 含量% 43.82 9.29 45.12 0.30 0.14 0.19 0.60 0.54 原子系数 1 0.159 0.77 0.002 0.001 0.002 0.005 0.063 8 7-1 含量% 34.28 1.06 64.66 100 原子系数 1 0.002 0.98 2 9 0608-1 含量% 37 20.32 37.97 3.51 0.12 0.76 0.32 100 原子系数 1 0.412 0.533 0.047 0.001 0.005 0.002 2 10 0608-2 含量% 35.23 21.53 35.29 4.45 0.12 1.37 2.0 100 原子系数 1 0.458 0.52 0.062 0.001 0.008 0.013 2 11 0608-3 含量% 39.46 38.61 19.77 1.54 0.24 0.39 100 原子系数 1 0.734 0.24 0.019 0.003 0.002 2
下载: 导出CSV
表 3 碳硅石颜色与元素含量对比
Table 3. Relation between color and element content of moissanite
样号 位置 颜色 百分含量/% 26~68 0.1~19 0.1~1 0.01~0.1 ＜0.01 微量 1-1 边缘 淡绿色-淡蓝色 C, Si 1-2 中心 淡绿色-淡蓝色 C, Si 1-3 包体 淡绿带灰 C, Si Fe Ni, Ti 1-4 包体 淡绿色 C, Si Fe Ni 4-1 边缘 暗绿色-黑色 C, Si 5-1 边缘 淡绿色 C, Si O K, Ca, S, Cl 5-5 包体 淡绿色 C, Si O 7-1 边缘 黑色 C, Si O Al，Mg 0608-1-2-3 C, Si Al, Fe 8 蓝色 C, Si Al 9 青绿色 Si, C Na, Ca Fe, Mg, Cr α-SiC** 无色 Si, Al - Na, Ca Fe, Mg, Cr Mn, Sn, Pb Ti, Ni, Be α-SiC** 蓝绿色 Si, Al Ca - Ti Mn α-SiC** 黄绿色 Si, Al Fe, Mg, Cr Mn, Pb, Cu 人造SiC** 绿色 Si, Al Ni Cu, V, Ag, Be, Sn, Pb 黑色 Si, Al Fe, Ca V Mn, Cu, Sn 蓝色 Si, Al Ca, Na Mg, Fe, Cr - 注：8、9为人造∗SiC；α-SiC∗资料据参考文献[11]
下载: 导出CSV
表 4 碳硅石流体包裹体成分
Table 4. Compositions of fluid inclusion in moissanites
相成分 气相 液相 碳硅石 序号 编号 CH4 C2H6 C3H8 C6H6 H2O CH4 C2H6 C3H8 C6H6 H2O 1 S-01 √ √ a S-02 √ √ √ √ √ 2 S-03 √ √ √ √ a S-04 √ √ √ √ 3 S-05 √ √ d S-4-2 √ √ 4 SP-1 √ √ d 5 S-08-1 √ √ √ √ a S-08-2 √ √ √ √ 6 S-09-1 √ √ √ a S-09-2 √ √ √ 注：a、d为图版Ⅱ中的代号
下载: 导出CSV
-
[1] Nassau K, 陈钟惠.莫依桑石:一种新的合成宝石材料[J].宝石和宝石学杂志, 1999, 1(4): 47-55. http://www.cnki.com.cn/Article/CJFDTOTAL-BSHB199904012.htm
[2] Kaminskiy F V, Bukin V I, Potapov S V, et al. Discovery of sil-icon cabide under natural conditions and their genetic importance[J]. International Geology Review, 1969, 11(5): 561-569. doi: 10.1080/00206816909475090
[3] 徐树桐, 吴维平, 肖万生, 等.大别山南部天然碳硅石[J].岩石矿物学杂志, 2006, 25(4): 314-322. http://www.cnki.com.cn/Article/CJFDTOTAL-YSKW200604006.htm
[4] Xu S T, Wu W P, Xiao W S, et al. Moissanite in serpentinite from the Dabie Mountains in China[J].Mineralogical Magazine, 2008, 72(4):899-908. doi: 10.1180/minmag.2008.072.4.899
[5] 靳永斌, 支霞臣, 孟庆, 等.大别山北部饶拔寨超镁铁岩体的形成时代:Re-Os同位素法定年[J].科学通报, 2003, 48(24): 2560-2565. http://www.cnki.com.cn/Article/CJFDTOTAL-KXTB200324015.htm
[6] 李曙光, S, R, Hart, 郑双根等.中国华北、华南陆块碰撞时代的钐、钕同位素年龄证据[J].中国科学 (B辑化学生命科学地学), 1989, 3: 312-319. http://www.cnki.com.cn/Article/CJFDTOTAL-JBXK198903011.htm
[7] 张旗, 马宝林, 刘若新, 等.一个消减带之上的大陆岩石圈地幔残片——安徽饶拔寨超镁铁岩的地球化学特征[J].中国科学 (B辑), 1995, 25(8): 867-873. http://www.cnki.com.cn/Article/CJFDTOTAL-JBXK199508012.htm
[8] 刘雅琴, 胡克.中国中部高铝质超高压变质岩[J].岩石学报, 1999, 15(4): 548-556. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB199904006.htm
[9] 斯利蒙斯等著; 苏树春, 张绍宗译.旋转台鉴定法译文集旋转台新技术[M].北京:地质出版社, 1997:43-52.
[10] 孙先如.应用消光数据测定晶体2V[J].矿物学报, 1983, 2: 112-117. http://www.cnki.com.cn/Article/CJFDTOTAL-KWXB198302004.htm
[11] Bauer J, Fiala J, Hrichová R. Natural α-silicon carbide[J]. America Mineralogist, 1963, 48(5): 620-634.
[12] Leung I S, Taylor L A, Tsao C S, et al. SiC in Diamond and Kimberlites: Implications for Nucleation and Growth of Diamond[J]. International Geology Review, 1996, (7): 595-606. https://www.researchgate.net/publication/233063657_SiC_in_Diamond_and_Kimberlites_Implications_for_Nucleation_and_Growth_of_Diamond
[13] 徐培苍, 李如璧, 王永强, 等.地学中的拉曼光谱[M].西安:陕西科学技术出版社, 1996.
[14] 路凤香.深部地幔及深部流体[J].地学前缘, 1996, 3(3/4): 181-186. http://www.cnki.com.cn/Article/CJFDTOTAL-DXQY604.002.htm
[15] Filimonova L G, Trubkin N V. Moissanite nanoparticles in disseminated mineralization of the Dukat ore district, northeastern Russia[J]. Doklady Earth Sciences, 2004, 394(1): 137-140. https://www.researchgate.net/publication/297988528_Moissanite_nanoparticles_in_disseminated_mineralization_of_the_Dukat_ore_district_northeastern_Russia
[16] Leung W, Guo I, Friedman J G. Natural occurrence of silicon carbide in a diamondiferous kimberlite from Fuxian[J]. Nature, 1990, 346: 352-354. doi: 10.1038/346352a0
[17] Whitney E D, Shafler P T B. Investigation of the phase transformation between α-and β-silicon carbide at high pressures[J]. High Temperatures-High Pressures, 1969, 1(1): 107-110.
[18] Lane, CHC Jr, Davis R F. Kinelics and mechanisms of high-temperature creep in silicon carbide[J]. Journal of the American Ceramic Society, 1988, 71(4): 281-295. doi: 10.1111/jace.1988.71.issue-4
[19] 董云鹏, 周鼎武, 张国伟. 蛇纹岩中地幔橄榄岩的显微构造特征及其地球动力学意义[C]//张旗. 蛇绿岩与地球动力学研讨会论文集. 北京: 地质出版社, 1996: 150-153.
-
图(8)
表(4)
计量
- 文章访问数: 1059
- PDF下载数: 6
- 施引文献: 0