Characterization of Illite Clays associated with the Sinongduo low sulfidation epithermal deposit, Central Tibet using field SWIR spectrometry

•The wavelength 1455 nm is important for the mineralization.•Silicification variation can indicate the fluid flow direction.•Illite crystallinity is associated with mineralization and metallogenic environment.•Illite mapping with SWIR can judge whether low sulfidation epithermal deposit is.