摘要
湖北省枣阳县石英-正长岩中的锆石,晶体大,粒径达10-50mm。整个晶体从中心向边缘由约600条灰白色与黑褐色相间的环带组成。物性、化学成分、X射线粉晶衍射、红外光谱、差热和阴极射线发光等测试分析结果表明,灰白色环带为遭受非晶质化的变水锆石,黑褐色环带为普通锆石。两种环带性质上的差别;主要与锆石中杂质元素UO_2和HfO_2含量的不同有关,反映了锆石晶体形成过程中杂质元素浓度的波浪式变化。
Zircon in quartz syenite from Zaoyang County, Hubei Province, is characterized in largecrystals with zonal structure. Crystal size 10-50mm, short prism with bipyramids, length/widthratio 1.7-2.1. About 600 interbanded greyish white and black brown layerings are recognized in onecrystal. The greyish white zones are identified as metamict malacon, Hv=1018-1114 kg/mm^2,SG=4.502, unit cell parameters a_0=b_0=6.624 A, c_0=6.005 A, EDS analysis gives: SiO_2 33.15-33.52%, ZrO_2 61.31-62.57%, HfO_2 2.13-2.57%, UO_2 0.76-1.59%. FeO 0.37-1.04%, CaO 0.20-1.02%.The black brown zones consist of ordinary zircon. Hv=1353-1504 kg/mm^2. SG=4.626, unitcell parameters a_0=b_0=6.608 A. c_0=5.985 A. Major chemical composition is SiO_2 33.34-34.74%ZrO_2 62.27-64.14%, HfO_2 2.04-2.62%. UO_2 0.00-0.06%, FeO 0.27-0.44%, CaO 0.00-0.08%.Difference in properties of the two zones mainly relates to their different contents of UO_2 andHfO_2.
关键词
正长岩
石英
锆石
环带
zircon
zoning
physico
chemistry property analysis
Hubei
