寺巷口普通球粒陨石的热变质和冲击变质历史研究

寺巷口陨石是一块经历强冲击变质的普通球粒陨石.系统研究陨石主体和冲击熔融脉的岩相学和矿物学.该陨石中球粒较少且轮廓和内部结构均模糊不清,基质重结晶程度高,橄榄石和辉石的成分非常均一.单斜辉石-斜方辉石矿物对计算得到的平衡温度峰值为891 4-36°C.说明寺巷口陨石的热变质程度与6型一致.陨石主体中的橄榄石具有明显的波状消光和面状变形裂隙,熔长石广泛存在,在冲击熔融脉中含有粗粒的林伍德石和镁铁榴石以及细粒的高压矿物组合,这些特征预示了寺巷口陨石经历了S6级的冲击变质作用且形成冲击脉的峰期压力可能在20 GPa-24 GPa左右,而温度可能高于2000°C.冲击熔融脉中自磷钙矿和铬铁矿的存在可能是因为经历了较长的退火时间,导致其高压矿物的回退.     

Ion Probe Study of Silicate Inclusions from Colomera （IIE） Iron Meteorite： the Rare Earth Element Perspective

Coupled with a petrographical study, I carried out an ion probe study of rare earth element microdistributions in mineral phases of silicate inclusions from the Colomera IIE iron meteorite. Most mineral grains have homogeneous REEs, but show considerable inter-grain variations by a factor of 2 to 100. The whole rock REE abundances for Colomera,estimated by combining REE data with modal abundances, are relatively LREE-enriched with REEs of～10’CI, which suggest that Colomera silicates were highly differentiated and might represent a low degree partial melt (-10%) of a chondritic source. REE geochemistry of Colomera silicate inclusions points to an origin that involves differentiation,dynamic mixing, remelting, reduction, recrystallization, and subsequent rapid cooling near the surface of a planetary body.     

澳大利亚——一颗陨落的巨星

提出了澳大利亚是地球上一颗陨落的卫星的假说。６７００万年前,地球曾吸引它自己的一颗卫星,撞击在东非－马达加斯加附近,这颗卫星就是澳大利亚。澳大利亚的地表上的下陷过程在不断东移,造成它北面和东面半圆殂的弧形构造。由于撞击作用,使太平洋洋底的部分岩体飞升到天上,成为我们头上的这轮月亮。新月亮在飞升时,把太平洋北面和西面施曳成花彩般的弧形构造,并把美洲西部推覆成笠迪勒拉（落矶山）山脉和安第斯山脉。     

Ca-, Al-rich Inclusions in Three New Carbonaceous Chondrites from the Grove Mountains, Antarctica: New Evidence for a Similar Origin of the Objects in Various Groups of Chondrites

Three new carbonaceous chondrites (GRV 020025,021579 and 022459) collected from the Grove Mountains (GRV), Antarctica, have been classified as the CM2, CO3 and CV3 chondrites, respectively. A total of 27 Ca- and Al-rich inclusions have been found in the three meteorites, which are the earliest assemblages formed in the solar nebula. Most of the inclusions are intensively altered, with abundant phyllosilicates in the inclusions from GRV 020025 and FeO enrichment of spinel in those from GRV 022459. Except for one spinel-spherule in each of GRV 020025 and     

搜寻天外来客

俄罗斯科学家和新闻记穿过荒无人烟的西伯利亚原始森林，奔赴由美国军事卫星测定的神秘天体和地球相撞那一瞬间坐标的地点。就住那里，在名叫妈妈新村的周边地区，他们找到了首批“物证”——一颗大陨星爆炸的痕迹。