The relation between the crystallography of quartz, and upturned aeolian cleavage plates
The relation between the crystallography of quartz, and upturned aeolian cleavage plates
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石英晶体学与上翘风成解理板之间的关系
DOI：
10.1111/j.1365-3091.1980.tb01193.x
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发表时间：
1980
期刊：
影响因子：
3.5
通讯作者：
D. Krinsley
中科院分区：
文献类型：
--
作者：
William Wellendorf;D. Krinsley
利用X射线旋进照相机和扫描电子显微镜（SEM）研究了人工研磨石英砂颗粒的晶体学特征与风成砂表面结构的关系。将破碎的巴西石英筛分至250至350 μm，在桨轮装置中以8 m s-1模拟风成作用3 h，并用SEM拍照。选择一个典型的颗粒，并将1100多张照片组合在一起，以创建一个3 × 3米的照片模型;由于尺寸大，可以观察和测量各种特征之间的角度和线性关系。在通过旋进X射线分析确定颗粒中的c轴方向之后，最重要的风成特征与石英的晶体学有关。这些上翘的板片或解理板片可能代表了石英中平行于r（10 1）和z（01 1）解理的痕迹。块状区域似乎是平行于m（10 μ 0）的解理的表达。此外，35个实验性的、现代的和古代的石英砂颗粒上的板间距相当恒定。假设大多数沉积环境中的磨蚀作用与石英晶体学的作用方式相同，则沉积物和沉积岩中的许多细粉砂和粘土可能是平行于r和z解理面的磨蚀后解理的结果，而不太常见的块状颗粒可能是平行于m面的解理的结果。
The relation between the crystallography of artificially abraded quartz sand grains and aeolian surface textures has been studied using an X-ray precession camera and the scanning electron microscope (SEM). Crushed Brazilian quartz was sieved to between 250 and 350 μm, eroded in a paddle wheel device which simulated aeolian action at 8 m s−1 for 3 h, and photographed with the SEM. A typical grain was selected and over 1100 photographs were combined to create a 3 × 3 m photomosaic; because of the large size, it was possible to observe and measure the angular and linear relations between the various features. After the c axis direction in the grain was determined by precession X-ray analysis, the most important aeolian features were related to the crystallography of quartz. The upturned plates or cleavage plates probably represent traces parallel to r(10Ī1) and z(01Ī1) cleavages in quartz. Blocky areas appear to be an expression of a cleavage parallel to m(10Ī0). In addition, plate spacing on thirty-five experimental, modern, and ancient quartz sand grains is fairly constant. Assuming that abrasion in most sedimentary environments acts in the same manner with respect to quartz crystallography, much of the fine silt and clay in sediments and sedimentary rocks may be the result of cleavage following abrasion parallel to the r and z cleavage planes, while the less common blocky particles are probably the result of cleavage parallel to the m planes.