Testing fundamental constraints on the origin of planetary materials

测试行星材料起源的基本限制

• 批准号: 314056533
• 负责人: Privatdozent Dr. Dominik Hezel
• 金额: --
• 依托单位: Abteilung Petrologie und Geochemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/314056533?language=en
• 关键词: Testing; fundamental; constraints; origin; planetary

The major component of most primitive, chondritic meteorites are chondrules, <0.1 to 2 mm sized, once molten droplets with igneous textures. Understanding the origin and formation of chondrules is one of the most important questions in meteoritics. The planned research will shed more light on the mechanism of chondrule formation. Carbonaceous chondrites contain about 50% chondrules and 50% fine-grained matrix. Both components have different chemical compositions. The combination of both is in many cases spot on the solar composition. We have shown this kind of relationship for Fe, Mg, Si, and Cr. We also found that refractory elements in chondrules and matrix are sometimes fractionated, such as high Ti/Al ratios in chondrules and low ratios in matrix of CR meteorites or occasional fractionations of Ca and Al, as is the case in CV chondrites. Recently, we even found a complementary relationship in the trace elements Hf and W, as well as in W-isotopes. This is of particular importance, because the Hf-W system can be used to date chondrule and matrix formation. This provides an even more detailed understanding of the chondrule matrix relationship. We demonstrated this in a recent publication. Understanding the chondrule matrix relationship will provide pivotal constraints to support and reject currently suggested hypotheses for chondrule formation. In addition, a scenario for chondrule formation may be concluded.¿In the present project we propose to study the origin of the chondrule-matrix fractionations. In addition, we want to extent our previous studies that focused on carbonaceous chondrites to other chondrite groups, R and ordinary chondrites. To understand complementarity and its implications for chondrule formation, we need extensive analyses of matrix and chondrules, which will be obtained by electron microprobe and solution based MC-ICP-MS analysis.

大多数原始陨石的主要成分是陨石球粒，尺寸小于0.1至2毫米，曾经是熔融液滴，具有火成岩纹理。了解陨石球粒的起源和形成是陨石学中最重要的问题之一。计划中的研究将揭示更多关于球粒形成的机制。碳质方解石含有约50%的球粒和50%的细粒基质。这两种成分具有不同的化学成分。两者的结合在许多情况下是太阳组成的一部分。我们已经证明了Fe、Mg、Si和Cr的这种关系。我们还发现，在球粒和基质中的耐火元素有时分馏，如高Ti/Al比在球粒和CR陨石或偶尔分馏的Ca和Al的基质中的低比率，是在CV陨石的情况下。最近，我们甚至发现了微量元素Hf和W以及W同位素的互补关系。这是特别重要的，因为Hf-W系统可以用来确定球粒和基质形成的日期。这提供了一个更详细的了解球粒矩阵的关系。我们在最近的一份出版物中证明了这一点。了解球粒基质的关系将提供关键的限制，以支持和拒绝目前提出的假说球粒形成。此外，还可以推断出球粒形成的情景。在本项目中，我们建议研究的起源的球粒基质分馏。此外，我们希望将我们以前的研究集中在碳质球粒陨石到其他球粒陨石群，R和普通球粒陨石。为了了解互补性及其对球粒形成的影响，我们需要对基质和球粒进行广泛的分析，这将通过电子探针和基于溶液的MC-ICP-MS分析来获得。