The size distribution, abundance, and physical and chemical characteristics of chondritic inclusions are key features that define the chondrite groups. We present statistics on the size and abundance of the macroscopic components (inclusions) in the Murchison (CM2) and Allende (CV3) chondrites and measure their general chemical trends using established X‐ray mapping techniques. This study provides a fine‐scale assessment of the two meteorites and a semiquantitative evaluation of the relative abundances of elements and their distribution among meteorite components. Murchison contains 72% matrix and 28% inclusions; Allende contains 57% and 43%, respectively. A broad range of inclusion sizes and relative abundances has been reported for these meteorites, which demonstrates the necessity for a more standardized approach to measuring these characteristics. Nonetheless, the characteristic mean sizes of inclusions in Allende are consistently larger than those in Murchison. We draw two significant conclusions (1) these two meteorites sampled distinct populations of chondrules and refractory inclusions, and (2) complementary Mg/Si ratios between chondrules and matrix are observed in both Murchison and Allende. Both support the idea that chondrules and matrix within each chondrite group originated in single reservoirs of precursors with approximately solar Mg/Si ratios, providing a constraint on astrophysical models of the origin of chondrite parent bodies.

中文翻译：

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Murchison CM2和Allende CV3球粒陨石的比较

球粒晶包裹体的尺寸分布，丰度以及理化特性是定义球粒晶群的关键特征。我们提供了关于Murchison（CM2）和Allende（CV3）球粒陨石中宏观成分（包含物）的大小和含量的统计数据，并使用已建立的X射线映射技术测量了它们的总体化学趋势。这项研究提供了对两个陨石的精细评估，并对元素的相对丰度及其在陨石成分之间的分布进行了半定量评估。默奇森（Murchison）含有72％的基质和28％的夹杂物；阿连德分别占57％和43％。据报道，这些陨石的夹杂物大小和相对丰度范围很广，这表明了采用更标准化的方法来测量这些特征的必要性。尽管如此，阿连德（Allende）的夹杂物特征平均尺寸始终大于默奇森（Murchison）。我们得出两个重要的结论（1）这两个陨石采样了不同种类的软骨和难熔夹杂物（2）在Murchison和Allende中都观察到了软骨和基质之间的互补Mg / Si比。两者都支持这样的想法，即每个球粒陨石群中的球粒和基质都起源于单个前体的单个储集层，其前体的太阳Mg / Si比率近似，从而限制了球粒陨石母体起源的天体模型。我们得出两个重要的结论（1）这两个陨石采样了不同种类的软骨和难熔夹杂物（2）在Murchison和Allende中都观察到了软骨和基质之间的互补Mg / Si比。两者都支持这样的想法，即每个球粒陨石群中的球粒和基质都起源于单个前体的单个储集层，其前体的太阳Mg / Si比率近似，从而限制了球粒陨石母体起源的天体模型。我们得出两个重要的结论（1）这两个陨石采样了不同种类的软骨和难熔夹杂物（2）在Murchison和Allende中都观察到了软骨和基质之间的互补Mg / Si比。两者都支持这样的想法，即每个球粒陨石群中的球粒和基质都起源于单个前体的单个储集层，其前体的太阳Mg / Si比率近似，从而限制了球粒陨石母体起源的天体模型。