Hyperspectral reflectance has the potential to provide rapid and low-cost mineralogical and chemical information that can be used to vector in mineral systems. However, the spectral signature of white mica and chlorite, despite numerous studies, is not fully understood. In this study, we review the mineralogy and chemistry of different white mica and chlorite types and investigate what mineralogical and chemical changes are responsible for the apparent shifts in the shortwave infrared (SWIR) spectroscopic absorption features. We demonstrate that the spectral signature of white mica is more complex than previously documented and is influenced by the Tschermak substitution, as well as the sum of interlayer cations. We show that an increase in the interlayer deficiencies towards illite is associated with a change from steep to shallow slopes between the wavelength position of the 2200 nm feature (2200 W) and Mg, Al_(VI) and Si. These changes in slope imply that white micas with different elemental chemistry may be associated with the same 2200 W values and vice versa, contrary to traditional interpretation. We recommend that traditional interpretations should only be used in true white mica with sum interlayer cations (I) > 0.95. The spectral signature of trioctahedral chlorite (clinochlore, sheridanite, chamosite and ripidolite) record similar spectral relationships to those observed in previous studies. However, dioctahedral Al-rich chlorite (sudoite, cookeite and donbassite) has a different spectral response with Mg increasing with 2250 W, which is the opposite of traditional trioctahedral chlorite spectral interpretation. In addition, it was shown that dioctahedral chlorite has a 2200 W absorption feature that may introduce erroneous spectral interpretations of white mica and chlorite mixtures. Therefore, care should be used when interpreting the spectral signature of chlorite. We recommend that spectral studies should be complemented with electron microprobe analyses on a subset of at least 30 samples to identify the type of muscovite and chlorite. This will allow the sum I of white mica to be obtained, as well as estimate the slope of 2200 W absorption trends with Mg, Al_(vi), and Si. Preliminary probe data will allow more accurate spectral interpretations and allow the user to understand the limitations in their hyperspectral datasets.

中文翻译：

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亚氯酸盐和白云母的矿物学，矿物化学和SWIR光谱反射率

高光谱反射具有提供快速和低成本的矿物学和化学信息的潜力，这些信息可用于在矿物系统中进行矢量化处理。然而，尽管进行了许多研究，但白云母和亚氯酸盐的光谱特征尚未完全被理解。在这项研究中，我们审查了不同的白云母和亚氯酸盐类型的矿物学和化学性质，并研究了哪些矿物学和化学变化导致短波红外（SWIR）光谱吸收特征的明显变化。我们证明白云母的光谱特征比以前记录的更为复杂，并且受Tschermak取代以及层间阳离子之和的影响。_（六）和Si。斜率的这些变化意味着与传统解释相反，具有不同元素化学性质的白云母可能具有相同的2200 W值，反之亦然。我们建议传统解释只能用于层间总和（I）> 0.95的真白云母。三八面体亚氯酸盐（斜绿石，蛇纹石，硅铁石和水滑石）的光谱特征记录了与先前研究中观察到的光谱关系相似的光谱关系。然而，富含铝的八面体亚氯酸盐（亚硫酸盐，方铁矿和辉绿岩）具有不同的光谱响应，Mg随2250 W的增加而增加，这与传统的三面体亚氯酸盐光谱解释相反。此外，结果表明，亚八面体亚氯酸八面体具有2200 W的吸收特性，这可能会引起白云母和亚氯酸盐混合物的错误光谱解释。因此，在解释亚氯酸盐的光谱特征时应格外小心。我们建议在光谱研究中至少应对至少30个样品的子集进行电子微探针分析，以鉴定白云母和亚氯酸盐的类型。这将获得白云母的总和I，并估计2200 W吸收趋势与Mg，Al的斜率_（vi）和Si。初步的探针数据将允许更准确的光谱解释，并允许用户了解其高光谱数据集中的局限性。