Thomas K L, Blanford G E, Keller L P, Klock W, McKay D S
Lockheed Engineering and Science Co., Houston, TX 77058, USA.
Geochim Cosmochim Acta. 1993;57:1551-66. doi: 10.1016/0016-7037(93)90012-l.
We have studied nineteen anhydrous chondritic interplanetary dust particles (IDPs) using analytical electron microscopy. We have determined a method for quantitative light element EDX analysis of small particles and have applied these techniques to a group of IDPs. Our results show that some IDPs have significantly higher bulk carbon abundances than do carbonaceous chondrites. We have also identified a relationship between carbon abundance and silicate mineralogy in our set of anhydrous IDPs. In general, these particles are dominated by pyroxene, olivine, or a subequal mixture of olivine and pyroxene. The pyroxene-dominated IDPs have a higher carbon abundance than those dominated by olivines. Members of the mixed mineralogy IDPs can be grouped with either the pyroxene- or olivine-dominated particles based on their carbon abundance. The high carbon, pyroxene-dominated particles have primitive mineralogies and bulk compositions which show strong similarities to cometary dust particles. We believe that the lower carbon, olivine-dominated IDPs are probably derived from asteroids. Based on carbon abundances, the mixed-mineralogy group represents particles derived from either comets or asteroids. We believe that the high carbon, pyroxene-rich anhydrous IDPs are the best candidates for cometary dust.
我们使用分析电子显微镜研究了19个无水球粒陨石星际尘埃颗粒（IDP）。我们确定了一种对小颗粒进行定量轻元素能量色散X射线分析（EDX）的方法，并将这些技术应用于一组IDP。我们的结果表明，一些IDP的总碳丰度明显高于碳质球粒陨石。我们还在我们的无水IDP组中确定了碳丰度与硅酸盐矿物学之间的关系。一般来说，这些颗粒以辉石、橄榄石或橄榄石和辉石的近似等量混合物为主。以辉石为主的IDP比以橄榄石为主的IDP具有更高的碳丰度。混合矿物学IDP的成员可以根据其碳丰度与以辉石或橄榄石为主的颗粒归为一组。高碳、以辉石为主的颗粒具有原始的矿物学和总体成分，与彗星尘埃颗粒有很强的相似性。我们认为，低碳、以橄榄石为主的IDP可能来自小行星。基于碳丰度，混合矿物学组代表来自彗星或小行星的颗粒。我们认为，高碳、富含辉石的无水IDP是彗星尘埃的最佳候选者。
