Plagioclase feldspar is one of the most abundant minerals on the surface of the Earth, the Moon, and Mars, and is also commonly found in meteorites. Studying shock effects in feldspar thus provides us with fundamental information about impact cratering processes on planetary bodies. In this study, plagioclase from monomict and polymict breccias, impact melt rocks, and shock‐metamorphosed target rocks, from throughout the Mistastin Lake impact structure, Canada, was examined using 514 nm laser Raman spectroscopy. As one of the very few impact structures with anorthosite in the target rocks, the Mistastin Lake impact structure provides a unique opportunity to study shocked plagioclase displaying progressive shock metamorphic features. A series of microscopic features was observed within plagioclase, including twins, needle‐like inclusions, planar features, and alteration. The lack of planar deformation features is notable. Raman spectra of these features suggest that this technique is capable of differentiating and classifying shock features in low to moderately shocked rocks. Caution should be exercised, however, as Raman spectra collected from unshocked plagioclase references with known compositions indicate that peak width and peak ratio of the Raman peaks in lower wave number region (<350 cm⁻¹) and the main signature peaks around 500 cm⁻¹ vary with chemical composition and crystal orientation. Data collected from diaplectic glass suggest that Raman features are efficient in distinguishing crystalline plagioclase and diaplectic glass. We also observed significant variations in the Raman intensities collected from diaplectic glass, which we ascribe to the localized disorder or inhomogeneity of shock pressure and temperature throughout the target.

中文翻译：

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拉曼研究加拿大Mistastin湖撞击构造斜长石长石的冲击特征

斜长石长石是地球，月球和火星表面上含量最丰富的矿物之一，并且也常见于陨石中。因此，研究长石的冲击效应为我们提供了有关行星陨石撞击坑过程的基本信息。在这项研究中，使用514 nm激光拉曼光谱技术研究了来自加拿大整个Mistastin湖撞击结构的单微米和多微米角砾岩，冲击熔岩和冲击变质目标岩的斜长石。作为目标岩石中极少有钙铁矿的冲击结构之一，Mistastin湖的冲击结构为研究表现出渐进的冲击变质特征的冲击斜长石提供了独特的机会。斜长石内观察到一系列微观特征，包括双胞胎，针状内含物，平面特征和变更。缺乏平面变形特征是值得注意的。这些特征的拉曼光谱表明该技术能够区分和分类低至中度冲击的岩石中的冲击特征。但是，应谨慎行事，因为从具有已知成分的未震荡斜长石参考文献中收集的拉曼光谱表明，在较低波数区域（<350 cm）的拉曼峰的峰宽和峰比^-1）和500 cm ^-1附近的主要特征峰随化学成分和晶体取向而变化。从透折玻璃收集的数据表明，拉曼特征在区分结晶斜长石和透折玻璃方面是有效的。我们还观察到从双折玻璃收集的拉曼强度有显着变化，这归因于整个目标的冲击压力和温度的局部无序或不均匀。