Combined TEM, NanoSIMS, Synchrotron XRF and STXM study of presolar grains and surrounding pristine matrix mineralogy with special emphasis on Acfer 094 and ALH77307

结合 TEM、NanoSIMS、Synchrotron XRF 和 STXM 研究太阳前颗粒和周围原始基质矿物学，特别侧重于 Acfer 094 和 ALH77307

• 批准号: 145819039
• 负责人: Professor Dr. Frank Erich Brenker
• 金额: --
• 依托单位: Max-Planck-Institut für Chemie (Otto-Hahn-Institut)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/145819039?language=en
• 关键词: Combined; TEM; NanoSIMS; Synchrotron; XRF

It is well documented that Acfer 094 and ALH 77307 are two of the most pristine meteorites ever found. The unusual high amount of presolar grains (> 160 ppm silicates, > 25 ppm oxides - Acfer094) within the matrix mineralogy combined with the recent development of site specific (FIB) and large area (ArIS) thin film preparation techniques for TEM investigations enable us to study the main and trace element content as well as structural characteristics of a large set of presolar silicates. The presolar grains and surrounding matrix mineralogy will be studied by TEM, NanoSIMS, synchrotron induced Nano-XRF and STXM. During the first project phase we not only developed the required preparation and measurement procedure but already identified 9 presolar grains applying the NanoSIMS technique within two successfully prepared large area thin films. The complete chemical and structural characterization of these grains will be the next important step. In addition we will extend our work to presolar grains from pristine CR-clan meteorites, which will be identified by a co-operated project (see proposal by Hoppe and Zipfel). The comprehensive study of presolar silicates will enable us to assess the conditions of formation around their parent stars, to reconstruct condensation - crystallization processes and to identify signs of processing in the ISM including amorphisation and re-crystallisation. We will also study the genetic relationship with the surrounding meteorite matrix. Thus, our multi-analytical studies of presolar grains and their surrounding matrix material will give us detailed information on the material from which our solar system formed.

有充分的证据表明，Acfer 094和ALH 77307是迄今为止发现的两颗最原始的陨石。在基质矿物学中异常高的前太阳颗粒（>为160 ppm的硅酸盐，>为25 ppm的氧化物- Acfer094）结合最近发展的特定位点（FIB）和大面积（ArIS）薄膜制备技术进行TEM研究，使我们能够研究大量前太阳硅酸盐的主要和微量元素含量以及结构特征。采用TEM、NanoSIMS、同步加速器诱导的纳米xrf和STXM等技术对太阳前颗粒及其周围基质矿物学进行了研究。在第一个项目阶段，我们不仅开发了所需的制备和测量程序，而且已经在两个成功制备的大面积薄膜中应用NanoSIMS技术确定了9个前太阳颗粒。这些颗粒的完整化学和结构表征将是下一个重要步骤。此外，我们将把我们的工作扩展到来自原始cr族陨石的前太阳颗粒，这将由一个合作项目来确定（见Hoppe和Zipfel的提议）。对太阳前硅酸盐的全面研究将使我们能够评估其母星周围的形成条件，重建凝聚结晶过程，并识别ISM中加工的迹象，包括非晶化和再结晶。我们还将研究其与周围陨石基质的成因关系。因此，我们对太阳系前颗粒及其周围基质材料的多分析研究将为我们提供太阳系形成物质的详细信息。