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代海洋地球化学的最佳代表之一，但人们对它们的形成及其不寻常性质的结构起源知之甚少。因此，在该项目中，将研究纤维状径向方解石的块体和表面结构和成分以及种子形成和生长条件。利用晶体学技术，例如晶体结构分析、全局和空间解析以及表面的成分和结构分析，将获得结构、成分和形貌的最完整的关系。天然和合成（实验）样品的比较应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，节奏生长的问题也将得到解决。特别值得关注的是改变母液成分对晶体形态和成分的影响。所有产品都将进行晶体学表征。此外，考虑微晶的形成条件，将研究氨基酸、糖、木质素等有机分子对生长过程的影响。为了了解原子分辨率的过程，从与这些有机物相互作用的大型方解石晶体的模型系统中，将使用掠入射 X 射线衍射 (GIXRD) 和原子力显微镜来分析包括有机附加层的表面结构。 AFM）实验。