Quantifying Soil Goethite/Hematite Ratios: A New Method Based on Diffuse Reflectance Spectra

Abstract Goethite/hematite ratios in soils are widely used to reconstruct past climatic changes, but their accurate measurements have remained challenging due the matrix effect. Here we present a new method for measuring soil goethite/hematite by characterizing band position of electron pair transition (EPT) based on diffuse reflectance spectra processed continuum removal. We introduce “half‐band‐area wavelength”, λ 1/2 , characterize EPT and validate using synthetic standards made from mixing pure goethite hematite four sets goethite‐ hematite‐free matrices derived arid aeolian deposits tropical saprolite. A consistent ‐goethite/hematite relation across demonstrates that our eliminates further applying it quantify 180‐Kyr loess‐paleosol sequences comparing results reported paleoclimatic records. Our is promising improving measurement sediments.