CM‐like interplanetary dust particles in lower stratosphere during 1989 October and 1991 June/July
CM‐like interplanetary dust particles in lower stratosphere during 1989 October and 1991 June/July
复制标题
1989年10月和1991年6月/7月平流层低层中的类CM行星际尘埃颗粒
DOI：
10.1111/j.1945-5100.1996.tb02024.x
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发表时间：
1996
影响因子：
2.2
通讯作者：
F. Rietmeijer
中科院分区：
文献类型：
--
作者：
F. Rietmeijer
- 平流层行星际尘埃L2005T12和L2011O3与CM球粒陨石基质有关。颗粒L2005T12主要由部分脱水的富含绿长石的蛇纹石的片状颗粒组成。其非晶基体中含有丰富的蒙脱石纳米晶和环状的Fe、Ni、S单元。一个独特的分层（部分）磁赤铁矿边缘只发生在富含S的部分矩阵。形成这种边缘和镁耗尽矩阵发生在大气进入加热的颗粒。颗粒L2011O3在无定形低Al铁镁硅石基质中具有大的硫化铁和镁橄榄石颗粒。这种基质的含水结晶产生超细晶蒙脱石和浸染状硫化铁。两种颗粒的大气入口加热由部分氧化铁边缘、泡状硫化物和由于Mg的损失而导致的基质组合物的分散指示。虽然仍存在许多不确定性，但1984年、1989年和1991年平流层低层中的对流粗糙粒子（包括未知数量的CM类粒子）的高发生率表明其丰度存在年度变化。低平流层灰尘采样的时间对于收集这些颗粒至关重要。
— The stratospheric interplanetary dust particles L2005T12 and L2011O3 are linked to CM chondrite matrix. Particle L2005T12 is dominated by tabular grains of partially dehydrated greenalite-rich serpentine. Its amorphous matrix contains abundant smectite nanocrystals and annular Fe, Ni, S units. A uniquely stratified (partial) maghemite rim occurs only on S-rich parts of the matrix. Formation of this rim and Mg depletions in the matrix occurred during atmospheric entry heating of this particle. Particle L2011O3 has large iron sulfide and magnesiowustite grains in an amorphous low-Al, ferromagnesiosilica matrix. Hydrous crystallisation of this matrix produced ultrafine-grained smectites and disseminated iron sulfides. Atmospheric entry heating of both particles is indicated by the partial iron oxide rim, vesicular sulfides, and the scatter of matrix compositions due to loss of Mg. While many uncertainties remain, the high incidence of chondritic rough particles, which include an unknown amount of CM-like particles, in the lower stratosphere during 1984, 1989, and 1991 suggests annual variations in their abundances. The timing of lower stratospheric dust samplings is critical to collect these particles.