普通球粒陨石的冲击实验研究

在二级轻气炮动高压装置上用电探针技术测量了吉林球粒陨石(H5)的冲击压缩线,并在12.4,27.3,39.0,53.0,77.5,82.8和92.6 GPa冲压下,对7个吉林球粒陨石样品进行了人工冲击回收实验,对冲击回收样品进行了较为系统的冲击效应研究。研究结果表明,冲击事件不仅改变了普通球粒陨石原始组分的岩石学特征,而且影响其热释光和稀有气体等物理与化学特性。根据已知冲压下普通球粒陨石的冲击特征,对其各冲击变质强度的压标作了重新刻度。     

南极岩石样品中稀土元素的中子活化分析

用仪器中子活化分析技术,测定了南极岩石中8种稀土元素含量,讨论了不同岩石的稀土模式特点。     

STUDY ON CHEMICAL COMPOSITIONS OF 19 L AND LL CHONDRITES AND ITS APPLICATION IN TAXONOMY

Reported in this paper are precise INAA data on 19 L and LL chondrites (7 Chinese chondrites and 12 from other countries). The L and LL chondrite data normalized to Mg and to CI chondrite indicate that for several lithophiles (V, Al, Cr and Mn), the extent of scatter is low, similar to that observed in carbonaceous chondrites. The average concentration of siderophiles in the LL group is lower than that in the L group.On the basis of olivine composition and atomic ratio (Ir/Au), we reclassify the five previously labeled L ehondrites as LL members. The atomic ratios of Ir/Au in the LL chondrites are lower than those in the L chondrites (the division is set at an Ir/Au ratio of 2.5). The atomic ratio of Ir/Au appears to be a useful classification parameter for ordinary chondrites. Therefore, it can be considered as a new taxonomic parameter. Of the elements studied, Br, a high volatile, seems most likely to show thermometamorphic effects, depending on petrologic types. The concentration of bromine and the     

RAMAN SPECTROSCOPY OF C,H,L AND LL CHONDRITES AND ITS SIGNIFICANCE IN EXPLORING THE FORMATION ENVIRONMENTS OF METEORITES AND THEIR TAXONOMY

The comparison of Raman spectra of the chondrites (C, H, L, LL) has confirmed thatthere exist two types of meteorite carbon: one is the primary carbon present in carbonaceouschondrites (c) and the other is the secondary carbon contained in ordinary chondrites (H, L,LL). The parameter of order (I_G/I_D intensity ratio, similarly hereinafter) of primary car-bon tends to decrease with increasing petrologic type and it can reflect the temperature ofdust carrier at the time plasma gases in the early nebula were condensed to form primarycarbonaceous material and the hydrogen content in primary carbonaceous material. This kindof primary carbonaceous material maybe has not experienced late stage thermometamorphismwithin the parent body of chondrites, indicating that the carbonaceous chondrites wereformed and retained in the low temperature region of the solar system. The parameter oforder of the secondary carbon tends to increase with increasing petrologic type and it can re-flect the degree of graphitization o     

新疆铁陨石的演化历史及成因研究

本文根据新疆铁陨石矿物化学特征、多样品微量元素丰度特征和大气剥蚀消融产物微量元素分布特征讨论了其母体经历的演化历史过程和母体形减条件。指出了铁陨石Ni,Co,Ge,Ga,Cu,As,Au,W和Ir等微量元素丰度分布指示了母体经历的岩浆分异程度、分异时间和母体分异结晶序列。由此推测充分分异的大行星母体金属核具有相似的化学组成分布。     

19个L及LL球粒陨石化学组成的研究及其在分类学中的应用

本文对19个球粒陨石进行了25个元素的仪器中子活化分析、橄榄石的电子探针分析及岩石学研究。研究结果表明,LL群球粒陨石的Ir/Au原子比值比L群球粒陨石低,二者的分界比值为2.50,因此,Ir/Au的原子比值可作为普通球粒陨石(H,L及LL群)新的分类参数;根据球粒陨石中橄榄石的成分(Fa％)和Ir/Au原子比值的两维分类参数,将以前划分为L群的5个球粒陨石重新划分为LL群球粒陨石;普通球粒陨石中Br浓度随着球粒陨石母体热变质程度或岩石类型(3—6型)而有规律地减小。可作为划分岩石类型的重要标志之一,     

C,H,L,LL球粒陨石的Raman光谱研究及对陨石形成环境与分类的意义

本文对球粒陨石(C,H,L,LL)的Raman光谱比较研究证明,存在两种类型的陨石碳质:一是碳质球粒陨石(C)的原生碳质,它的有序参量(I_G/I_D强度比,下同)随岩石学类型升高而减小;另一是普通球粒陨石(H,L,LL)的次生碳质,它的有序参量随岩石学类型升高而增大,这些事实支持碳质球粒陨石起源于彗星和Alfven等人的由等离子体星云到行星的假说。