Dauphiné twinning as evidence for an impact origin of preferred orientation in quartzite: An example from Vredefort, South Africa
Dauphiné twinning as evidence for an impact origin of preferred orientation in quartzite: An example from Vredefort, South Africa
复制标题
DOI：
10.1130/g21163.1
复制
发表时间：
2005-04
期刊：
影响因子：
5.8
通讯作者：
H. Wenk;I. Lonardelli;S. Vogel;J. Tullis
中科院分区：
文献类型：
--
作者：
H. Wenk;I. Lonardelli;S. Vogel;J. Tullis
大型陨石撞击造成地球地质特征的巨大变化，从陨石坑和喷出物到矿物的相变。在这篇报告中，我们描述了冲击波对来自南非弗里德堡撞击地点的石英岩中石英晶体晶体取向的影响。用飞行时间中子衍射法测定了块状石英岩样品的择优取向。在c轴随机分布的情况下，正负菱形的取向分布存在微弱但明显的差异，如极图和逆极图所示。将自然弗里德堡试样的结果与变形试样进行了比较
Large meteorite impacts cause great changes to geologic features on Earth, ranging from cratering and ejecta blankets to phase transformations in minerals. In this report we describe the effect of a shock wave on the crystallographic orientation of quartz crystals in quartzite from the Vredefort impact site in South Africa. Preferred orientation of bulk quartzite samples was measured by time-of-flight neutron diffraction. With a random distribution of c-axes, a weak but distinct difference between the orientation distribution of positive and negative rhombs was observed, as illustrated with pole figures and inverse pole figures. Results for the natural Vredefort sample are compared with deformation