January 12, 2023 Dataset Open Access

Data publication: Underground hyperspectral outcrop scanning for automated mine-face mapping — the Lithium deposit of Zinnwald/Cínovec

Kirsch, Moritz; Mavroudi, Mary; Thiele, Samuel Thomas; Lorenz, Sandra; Tusa, Laura; Booysen, René; Herrmann, Erik; Fatihi, Ayoub; Möckel, Robert; Dittrich, Thomas; Gloaguen, Richard

As part of a project on the development of hyperspectral scanning to support geological mapping in underground mines, we acquired hyperspectral data from three adjacent outcrops of Sn-W-Li greisen rocks in the visitor’s mine of Zinnwald, Germany. The hyperspectral scans were pre-processed and then back-projected onto photogrammetric, three-dimensional digital outcrop models resulting in so-called "hyperclouds". The here presented hyperclouds from the three outcrops (Z1, Z2, and Z3) contain the following attributes:

ZX_Absorbance.ply
RGB colours: Mica/clay-zinnwaldite-topaz abundance based on absorbance (1 – hull-corrected reflectance) at 2200 nm (red), 2250 nm (green), and 2085 nm (blue)
Scalars: Absorbance at 2086.88 nm, 2160.69 nm, 2197.53 nm, 2209.8 nm, 2252.7 nm, and 2338.31 nm

ZX_Iron.ply
RGB colours: Composite (Fe3+ Fe2+ FeOH) iron index (red: 600/570 nm, green:(920 nm + 1650 nm)/ (1035 nm 1230 nm), blue: (2230 nm 2290 nm)/(2245 nm + 2260 nm)
Scalars: Fe3+ = 600/570 nm, Fe2+ = (920 nm + 1650 nm)/ (1035 nm + 1230 nm), FeOH = (2230 nm + 2290 nm)/(2245 nm + 2260 nm)

ZX_MNF.ply
RGB colours: Minimum noise fraction false colour (red: band 4, green: band 7, blue: band 5)
Scalars: Minimum noise fraction bands 4, 7, 5)

ZX_RGB_mineralogy_Li.ply
RGB colours: True colour RGB from photogrammetric outcrop model
Scalars: Mineral abundances derived by combining sample mineralogy from quantitative XRD measurements and hyperspectral unmixing approaches: Quartz/Feldspar, Zinnwaldite, Muscovite/Illite, Kaolinite, Topaz, Lithium (by multiplying the zinnwaldite abundance by its average lithium content of 1.7%)