Regolith-hosted rare earth element (REE) deposits predominate global resources of heavy REEs. Regoliths are underlain by various types of igneous rocks and do not always host economically valuable deposits. Thus a feasible and convenient method is desired to identify REE mineralization in a particular regolith. This study presents a detailed visible short-wave infrared reflectance (VSWIR) spectroscopic study of the Renju regolith-hosted REE deposit, South China, to provide diagnostic parameters for targeting REE orebodies in regoliths. The results show that the spectral parameters, M794_2^nd and M800_2^nd, derived from the VSWIR absorption of Nd³⁺ at approximately 800 nm, can be effectively used to estimate the total REE concentrations in regolith profiles. M1396_2^nd/M1910_2^nd ratios can serve as proxies to evaluate weathering intensities in a regolith. Abrupt changes of specific spectral features related to mineral abundances, chemical compositions, and weathering intensities can be correlated with variations of protolith that formed a regolith. These VSWIR proxies are robust and can be used for exploration of regolith-hosted REE deposits.

中文翻译：

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可见短波红外反射光谱表征风化层承载的稀土元素矿化的可行性

以风化层为载体的稀土元素 (REE) 矿床在全球重稀土资源中占主导地位。风化层下面有各种类型的火成岩，并不总是有经济价值的矿床。因此，需要一种可行且方便的方法来识别特定风化层中的 REE 矿化。本研究对华南连珠风化岩中的稀土元素矿床进行了详细的可见短波红外反射 (VSWIR) 光谱研究，以提供针对风化层中稀土元素矿体的诊断参数。结果表明，光谱参数 M794_2 ^nd和 M800_2 ^nd来自 Nd ³⁺的 VSWIR 吸收在大约 800 nm 处，可以有效地用于估计风化层剖面中的总 REE 浓度。M1396_2 ^nd /M1910_2 ^nd比率可以作为评估风化层风化强度的代理。与矿物丰度、化学成分和风化强度相关的特定光谱特征的突然变化可能与形成风化层的原岩变化有关。这些 VSWIR 代理非常强大，可用于勘探以风化层为载体的 REE 矿床。