摘要
应用探针分析所获化学成分(加以一定限制的),对辽宁宽甸新生代碱性玄武岩中3个巨晶单斜辉石进行晶体结构测定与修正。最终R因子分别为0.0239,0.0213和0.0196。结构中M2分裂为M 2和M 2′,分别由Ca^(2+)、Na^+等较大半径阳离子和Mg^(2+)、Fe^(2+)等较小半径阳离子占据。通过键价分析,阐明了M2′相对于M2的位移趋向及其配位情形。此外,讨论了Al的占位及其成因意义。
Based on the chemical composition by microprobe analysis, with some qualifications, the determination and refinement of the crystal structure of three megacryst clinopyroxenes occurring in the Cenozoic alkali basalt from Kuandian, Liaoning Province were carried out. The final R factors are equal to 0.0239, 0.0213 and 0.0196, respectively. In the crystal structures. it was found that the M2 crystal site splits into M 2 and M 2' occupied by Ca^(2+), Na^+ and K^+(the large cations) and by Mg^(2+), Fe^(2+) and Mn^(2+)(the small cations), respectively. Through the bond valence analysis, the following problems have been solved: (1) why is M2'closer to the coordinated O1 as compared with M2?(2)what is the exact coordination configuration of M2'?Furthermore, the occupancies of Al in T and M1 as well as the genetic information are also discussed.
出处
《矿物学报》
CAS
CSCD
北大核心
1993年第1期56-64,共9页
Acta Mineralogica Sinica
关键词
玄武岩
巨晶
斜辉石
晶体结构
alkali basalt
megacryst
clinopyroxene
crystal structure
crystal chemistry
