ALBERT

Description: The data set contains VNIR and SWIR raw and reference hyperspectral imaging data of the Apliki mine open cut and of samples from the surface of the mine measured in the laboratory. It is con-nected to the published spectral library and chemical analyses of 37 different surface materials from the copper-gold-pyrite mine Apliki in the Republic of Cyprus (Koerting et al., 2019). The field outcrop scan was acquired in March 2018 in cooperation with the Geological Survey Department of the Republic of Cyprus (GSD) and the German Research Centre for Geosciences (GFZ). The laboratory sample scan presented in this document is a collection of hyperspectral scans compiled in one large dataset. The hyperspectral data in the field and the lab were acquired with the HySpex sys-tem in a range of 414 – 2498 nm. The field data is shared as one VNIR and one SWIR radiance and reflectance data cube each. The laboratory data is shared as one full VNIR-SWIR (414 – 2450nm) reflectance data cube that was processed and corrected for the detector jump, data spikes and the last 8 SWIR bands were clipped due to a low signal to noise ratio (SNR). The data and the samples originate from fieldwork in the Republic of Cyprus and laboratory work at the GFZ Potsdam. A detailed description of the data acquisition and processing can be found in Koerting (2021).

Description: The data set contains mineral chemical analyses of 20 different copper bearing minerals and their corresponding hyperspectral spectra. The hyperspectral data were acquired with the HySpex system in a range of 400 – 2500 nm and are presented in a spectral library. Detailed information about the mineral specimen, sample area and geochemistry is presented in the data sheets and associated data description. The spectral library presented here is part of a bigger collection of spectral libraries.

Description: The data set contains mineral chemical analyses of 32 rare earth element (REE) -bearing minerals (REMin) and rare-earth oxides (REO) and their corresponding hyperspectral spectra. The hyperspectral data was acquired with the HySpex system in a range of 400 – 2500 nm and is presented in a spectral library. The two Rare Earth Element (REE) libraries consist of the spectra of 16 rare earth oxides powders (REO) and 14 REE-bearing minerals (REMin). In addition, it contains the spectra of niobium- and tantalum oxide, two elements technically not part of the REEs.

Description: The data set contains LIBS (Laser-Induced Breakdown Spectroscopy) emission spectra of 18 lithium-bearing minerals and their corresponding hyperspectral reflectance spectra. The data were collected within the research project LIGHTS (Lightweight Integrated Ground and Airborne Hyperspectral Topological Solutions, http://lights.univ-lorraine.fr/) which aims at developing a new exploration process for Li targets combining drone-borne hyperspectral data and field observations. Hyperspectral data were acquired with the HySpex system in a wavelength range of 414 - 2498 nm and are presented in a spectral library. Detailed information about the samples and area of spectral retrieval is presented in the data sheet below. The spectral library presented here expands the collection of spectral libraries including samples from rare-earth minerals, rare-earth-oxides (Koerting et al., 2019a) and copper-bearing minerals (Koellner et al., 2019) which are fully described in Koerting et al. (2021). These libraries aim to give a spectral overview of important resources and deposit mineralizations. 18 samples taken partly from the collections of the University of Potsdam (UP) and the Federal Institute for Geosciences and Natural Resources (BGR) and partly in the field during previous measurement campaigns were hyperspectrally measured and geochemically analysed by using a LIBS handheld analyzer. A description of the HySpex system in lab use can be found in Koerting et al. (2021). The lithium-bearing mineral samples were measured without prior sample preparation as the surface of the minerals and the influence of the mineral structure were of interest (Figure 1). Figure 1 shows one HySpex scan of four lepidolite samples (Lep1, Lep2, Lep3, Lep4) displayed as a true color RGB image in order to show the untreated samples and the white reflectance (WR) panel needed for the hyperspectral measurements (WR 90%).

Description: The data set contains chemical analyses of 32 different surface materials from the Bajoca feldspar mine in Portugal and their corresponding hyperspectral reflectance spectra. The field samples were collected in May 2019 within the LIGHTS (Lightweight Integrated Ground and Airborne Hyperspectral Topological Solutions) project. The goal in this project is to develop tools for hybrid data analysis of remote sensing data from different scales, geochemical and geological data for Li target area exploration (LIGHTS; Cardoso-Fernandes et al. (2020a,b & 2021) & Fabre et al. (in prep.)). The hyperspectral data were acquired in the laboratory with the HySpex system in a range of 414 – 2498nm and on-site with the Spectral Evolution PSR+ 3500 handheld spectroradiometer (short “PSR+”) in a range of 350 – 2500nm. The sample spectra of 32 different surface samples are presented for both sensors systems. The resulting HySpex reflectance data are scaled from 0 – 10000, the PSR+ reflectance data are scaled from 0-1. Detailed information about the samples and geochemistry is presented in the data sheets.

Description: Lithium (Li) is one of the latest metals to be added to the list of critical materials in Europe and, thus, lithium exploration in Europe has become a necessity to guarantee its mid- to long-term stable supply. Laser-induced breakdown spectroscopy (LIBS) is a powerful analysis technique that allows for simultaneous multi-elemental analysis with an excellent coverage of light elements (Z 〈 13). This data paper provides more than 4000 LIBS spectra obtained using a handheld LIBS tool on approximately 140 Li-content materials (minerals, powder pellets, and rocks) and their Li concentrations. The high resolution of the spectrometers combined with the low detection limits for light elements make the LIBS technique a powerful option to detect Li and trace elements of first interest, such as Be, Cs, F, and Rb. The LIBS spectra dataset combined with the Li content dataset can be used to obtain quantitative estimation of Li in Li-rich matrices. This paper can be utilized as technical and spectroscopic support for Li detection in the field using a portable LIBS instrument.

Description: The integration of imaging spectroscopy and aeromagnetics provides a cost-effective and promising way to extend the initial analysis of a mineral deposit. While imaging spectroscopy retrieves surface spectral information, magnetic responses are used to determine magnetization at both shallower and greater depths using 2D and 3D modeling. Integration of imaging spectroscopy and magnetics improves upon knowledge concerning lithology with magnetic properties, enhances understanding of the geological origin of magnetic anomalies, and is a promising approach for analyzing a prospective area for minerals having a high iron-bearing content. To combine iron diagnostic information from airborne hyperspectral and magnetic data, we (a) used an iron absorption feature ratio to model pseudo-magnetic responses and compare them with the measured magnetic data and (b) estimated the apparent susceptibility along the surface by some equivalent source modeling, and compared them with iron ratios along the surface. For this analysis, a Modified Iron Feature Depth index was developed and compared to the surface geochemistry of the rock samples in order to validate the spectral information of iron. The comparison revealed a linear increase in iron absorption feature depths with iron content. The analysis was performed by empirically modeling the statistical relationship between the diagnostic absorption features of hyperspectral (HS) image spectra of selected rock samples and their corresponding geochemistry. Our results clearly show a link between the spectral absorption features and the magnetic response from iron-bearing ultra/-mafic rocks. The iron absorption feature ratio of Fe3+/Fe2+ integrated with aeromagnetic data (residual magnetic anomaly) allowed us to distinguish main rock types based on physical properties. This separation matches the lithology of the Niaqornarssuit complex, our study area in West Greenland.