Impact of composition and local, bulk and surface structure of fibrous carbonates on their fabric and morphology

纤维状碳酸盐的组成以及局部、整体和表面结构对其织物和形态的影响

• 批准号: 218324714
• 负责人: Professor Dr. Hermann Gies
• 金额: --
• 依托单位: Institut für Geologie, Mineralogie und Geophysik
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/218324714?language=en
• 关键词: Impact; composition; local; bulk; surface

Although carbonates containing radiaxial fibrous and/or fasicular optical calcite cements are considered to be one of the best proxies for the geochemistry of ancient oceans, their formation and the structural origin of their unusual properties are only poorly understood. Therefore, in this project bulk and surface structure and composition of fibrous radiaxial calcites will be studied together with seed formation and growth conditions. Using crystallographic techniques such as the analysis of the crystal structure, globally and space resolved, and the analysis of the composition and structure of surfaces, a most complete relation of structure, composition and morphology will be obtained. The comparison of natural and synthetic (experimental) samples should allow for a rational understanding of processes involved. In crystal growth experiments also the question of rhythmic growth will be addressed. In particular the influence of changing composition of mother liquor on the morphology and composition of the crystal is of interest. All products will undergo crystallographic characterization. In addition, the influence of organic molecules such as amino acids, sugars, lignin etc. on the growth process will be studied considering micrite formation conditions. For an understanding of processes in atomic resolution, from model systems of large calcite crystals interacting with these organics, the structure of the surface including the organic add-layer will be analyzed using grazing incidence X-ray diffraction (GIXRD) and atomic force microscopy (AFM) experiments.

尽管含有径向纤维状和/或束状光学方解石胶结物的碳酸盐被认为是古海洋地球化学的最佳代用物之一，但它们的形成和其不寻常性质的结构起源却知之甚少。因此，在本项目中，将研究纤维状径向方解石的体积和表面结构和组成，以及种子的形成和生长条件。利用晶体学技术，如晶体结构的分析，全局和空间分辨，以及表面的组成和结构的分析，将得到一个最完整的结构，组成和形貌的关系。天然和合成（实验）样品的比较应该允许对所涉及的过程有一个合理的理解。在晶体生长实验中，也将讨论节律生长的问题。特别是改变母液的组成对晶体的形态和组成的影响是感兴趣的。所有产品都将进行晶体学表征。此外，考虑到泥晶的形成条件，将研究有机分子如氨基酸、糖、木质素等对生长过程的影响。为了理解原子分辨率的过程，从大方解石晶体与这些有机物相互作用的模型系统中，将使用掠入射x射线衍射（GIXRD）和原子力显微镜（AFM）实验分析表面结构，包括有机添加层。