南极MIL090070月球陨石的岩石矿物学特征  

PETROLOGY AND MINERALOGY OF LUNAR METEORITE MIL 090070 FROM ANTARCTICA

作　　者：姚杰[1,2] 缪秉魁[1,2] 陈宏毅[1,2] 谢兰芳[1,2] 夏志鹏[1,2] 

机构地区：[1]桂林理工大学广西矿冶与环境科学实验中心,广西桂林541004 [2]广西隐伏金属矿产勘查重点实验室,广西桂林541004

出　　处：《极地研究》2013年第4期329-341,共13页Chinese Journal of Polar Research

基　　金：国家自然科学基金(41173077);广西隐伏金属矿产勘查重点实验室主任基金项目(13-A-01-02);广西研究生教育创新计划资助项目(YCSZ2013074)资助

摘　　要：MIL 090070陨石是2009年美国南极陨石搜寻项目(ANSMET)在南极横断山脉米勒山区(Miller Range)发现的一块月球陨石,属于斜长岩质月表角砾岩。它具有典型的碎屑结构,主要由岩屑、晶屑、玻屑和细粒基质组成。岩屑以复合斜长岩质岩屑和斜长岩岩屑为主,其次为辉长岩质斜长岩岩屑、辉长岩岩屑、辉长苏长岩岩屑、辉长岩质橄长岩岩屑和橄榄辉长岩岩屑等。晶屑有普通辉石、易变辉石、斜长石、尖晶石、石英和钛铁矿等矿物。玻屑主要为斜长石质的玻屑,呈细长或弯曲条状,多具裂纹。MIL 090070陨石的矿物组成主要为斜长石(86 vol%,An92—99)、橄榄石(6 vol%,Fo53—89)、辉石(7 vol%,En25—83Fs7—43Wo2—45)以及少量的尖晶石、钛铁矿和石英等;其中,辉石有单斜辉石和斜方辉石两种。MIL 090070陨石中橄榄石和辉石的Fe-Mn值分布明显不同于地球、火星、金星和小行星的样品,基本落在月球岩石范围。MIL 090070陨石在多期次冲击和胶结作用下,岩屑的矿物成分和粒度不断变化,岩屑类型更多样,更复杂。基于MIL 090070陨石的岩石矿物学特征、碎屑类型及结构的特征等研究,可以进一步丰富我们对月球物质的形成及月岩—月壤演化过程的认识。MIL 090070, a new lunar meteorite found in 2009, is a lunar highland anorthosite .It has a typical breccia texture that consists mainly of lithic , mineral and glassy clasts in a fine-grained matrix.Its lithic clasts include anorthositic polymicts , anorthosite , gabbro , gabbroic norite , gabbroic troctolite , gabbroic anorthosite and olivine-gabbro .Mineral clasts include augite , pigeonite , plagioclase , spinel , quartz and ilmenite .The glassy clasts are anorthositic .Its shapes are usually thin plate-like and bending plate-like with numerous fractures .The mineral as-semblage is mostly plagioclase （ 86 vol%, An92-99 ） , olivine （ 6 vol%, Fo53-89 ） , pyroxene （ 7 vol%, En25-83 Fs7-43 Wo2-45 ）, spinel, ilmenite and silica.In addition, the pyroxene has two kinds of augite （En25-63 Fs7-43 Wo6-45） and pigeonite （En55-83 Fs13-41 Wo2-5）.The Mn to Fe values of olivine and pyroxene plot mostly in the ar-ea of rocks with a lunar-origin, which is far from those of Earth , Mars, Venus and main-belt asteroids .MIL 090070 experienced many shock events and is cemented by shock-induced glassy breccias .Therefore , the mineral composition and grain size of the lithic clasts has changed gradually and the lithic clast types became more varied and complicate during the shock events .Examination of the petrology of MIL 090070 , including clast types and tex-tural features , will improve understanding of the process of lunar regolith formation .

关 键 词：月球陨石 MIL090070 高地斜长岩 月壤 

分 类 号：P185.83[天文地球—天文学]