我在美国陨石撞击坑网站（impactcraters.us）大概找到了PFs与PDFs的区别，有一章讲到撞击来源的颗粒尺度证据，其中讲到（英文为原文，蓝色为蹩脚翻译）：
Shatter cones and high pressure mineral polymorphs such as coesite and stishovite emerged as indicators of meteorite impact craters only a few years before grain-scale petrographic indicators. An understanding of microscopic changes in rocks subjected to shock metamorphism emerged from a combination of research on rocks from meteorite impact craters and rocks from nuclear test sites.
震裂锥和高压矿物同质异相体，如柯石英和斯石英，仅在颗粒尺度岩相指标出现前几年才作为陨石撞击坑的指标出现。通过对陨石撞击坑岩石和核试验场地岩石的综合研究，人们对遭受冲击变质作用的岩石的微观变化有了一个了解。
By 1966 two critically important pieces of microscopic evidence had been recognized in quartz, and to a lesser extent in other silicates. These were distinct, parallel fractures of mineral grains along cleavage planes, now called planar fractures, or PFs, and more closely spaced, parallel fracture-like features in grains that are now called planar deformation features, or PDFs. 到1966年，在石英中发现了两个极其重要的微观证据，在其他硅酸盐中也发现了一个。这些是沿解理面的矿物颗粒明显的平行裂隙，现在称为面状裂隙，或称PFs，以及颗粒中间隔更近的平行裂隙状特征，现在称为面状变形构造，或PDFs。
These features were initially used as an indicator of hypervelocity impact related shock deformation, since they either don't occure at all (PDFs), or occur very rarely (PFs) in rocks subjected to ordinary geologic processes. But their potential as a shock barometer, an indicator of the specific peak shock pressure to which a rock had been exposed, was soon recognized.
这些特征最初被用作超高速撞击相关冲击变形的指标，因为它们要么根本不发生（PDFs），要么在受普通地质过程影响的岩石中很少发生（PFs）。但它们作为冲击标记的潜力很快被认识到，冲击标记是岩石所暴露的特定峰值冲击压力的指示器。
Name Changes 名称改变
Understanding naming changes over time is necessary in order to make sense of earlier literature and avoid confusion.
为了理解早期文献并避免混淆，理解命名随时间的变化是必要的。
PFs and PDFs are not always distinguished from one another in literature from the 1960s and earlier, and the names of both have changed and refined over time. Both PFs and PDFs may be called planar elements in early work.
在20世纪60年代和更早的文献中，PFs和PDFs并不总是相互区别，它们的名称随着时间的推移而改变和完善。在早期的工作中，PFs和PDFs都可以称为平面要素。
PFs are sometimes called cleavage or microfaulting in earlier papers.
PFs在早期论文中有时被称为解理或微断层。
PDFs are slso called shock lamellae, planar lamellae, or planar elements in earlier papers. More recent work typically uses Planar Deformation Features (PDF), and distinguishes these from Planar Fractures (PF), which can form at lower levels of stress.
在早期的论文中，PDFs被称为冲击片层、平面片层或平面要素。最近的工作通常使用面状变形构造（PDF），并将其与面状裂隙（PF）区分开来，后者可以在较低的应力水平下形成。
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下面是网络上找的几张石英的PDFs照片，其中图1是中国辽宁的岫岩陨石坑钻取的岩石样品里面石英的PDFs，岫岩陨石坑是中国首个被证实的陨石坑（中国目前被科学证实的陨石坑好像只有两个，另一个是黑龙江的依兰陨石坑，确认陨石坑重要证据就是找到了附近岩石中的PDFs。很多在卫星地图上看起来像的疑似陨石坑，并没有找到充分的科学证据）。
图1 辽宁岫岩陨石坑中石英的PDFs 正交偏光
图2 乌克兰一个陨石坑中石英的PDFs 正交偏光
图3 芬兰一个陨石坑中石英的PDFs 单偏光
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发表于 2021-11-26 23:50:30
发表于 2021-11-27 09:12:13
