Building a universal orientation system for thin sections
Building a universal orientation system for thin sections
复制标题
构建薄切片通用定向系统
DOI：
10.1016/j.jsg.2018.09.019
复制
发表时间：
2019
影响因子：
3.1
通讯作者：
Roberts, Nicolas
中科院分区：
文献类型：
--
作者：
Tikoff, Basil;Chatzaras, Vasileios;Newman, Julie;Roberts, Nicolas
我们提出了一个用于显微分析的薄切片的定向系统，适用于坯料和芯。定向系统能够进行空间参照观测，由三个部分组成。首先，我们建立一个参考角，即薄切片上样品的最上角，在现场或实验室环境中的原始地理方向。该角与右手坐标系相关联，在该坐标系中，所有参考轴都指向下方。对于使用近水平方向薄剖面的项目，可以使用基于地理方向（而不是基于最上角点）的参考角点约定。参考角-与方向元数据结合-定义薄截面在地理空间中的唯一位置。其次，我们提出了一种小锯切（凹口）系统，其最小化样品上所需的凹口数量，以区分参考角和薄部分相对于织物的取向（例如，叶理/线理），如果存在。开槽标准的效用在于它提供了对薄切片方向的固有双重检查，并便于用户之间的共享。第三，我们开发了一个网格系统，以确定感兴趣的功能薄部分，相对于参考角。这些系统中的任何一个（参考、开槽和网格化）都可以独立使用。这些系统专门设计用于与目前正在开发的数字数据系统合作，使研究人员能够相互共享微观结构数据，并促进结构地质学领域的新型大数据科学。
We present an orientation system for thin sections used for microanalysis, applicable to both billets and cores. The orientation system enables spatially referenced observations and consists of three parts. First, we establish a reference corner that is the uppermost corner of the sample on the thin section, in its original geographic orientation in the field or laboratory setting. This corner is tied to a right-hand coordinate system, in which all reference axes point downward. A geographic direction-based, rather than uppermost corner-based, convention for a reference corner can be substituted for projects that utilize sub-horizontally oriented thin sections. The reference corner - combined with orientation metadata - define a unique position of the thin section in geographic space. Second, we propose a system of small saw cuts (notches) that minimizes the number of notches required on the sample, to distinguish both the reference corner and the orientation of the thin section relative to fabric (e.g., foliation/lineation), if present. The utility of a notching standard is that it provides an inherent doublecheck on thin section orientation and facilitates sharing between users. Third, we develop a grid system in order to locate features of interest on the thin section, relative to the reference corner. Any of these systems – referencing, notching, and gridding – can be used independently. These systems are specifically designed to work with digital data systems, which are currently being developed, allowing researchers to share microstructural data with each other and facilitating new types of big data science in the field of structural geology.