The NE Estonian Precambrian basement, comprising the Tallinn, Alutaguse, and Jõhvi zones, is part of the eastern Fennoscandian Shield. It comprises Paleoproterozoic back-arc basins with juvenile metal-rich volcanic–sedimentary sequences intruded by Svecofennian granitoids, forming an amphibolite- to granulite-facies basement whose lithological and metallogenic traits resemble those of the Swedish Bergslagen region and the Finnish Orijärvi district.
This study re-examines over 500 historical drill cores and related geophysical data to reassess the mineral potential of the NE Estonian basement. Cu–Zn–Pb and Au–Ag–As–Sb anomalies are linked with magnetite-rich and sulphide–graphite gneisses, while automated MSCL-XYZ scanning of archived drill cores uncovers multiple critical-metal associations, including Ni–Co–Cr, Mo–W–Bi, Sn–Zn–Cd, Cu–Ni, Nb–Y–P, and Au–Ag–As–Sb–Bi–W–Se–Sn. These patterns reveal previously unrecognised prospective intervals across the Tallinn, Alutaguse, and Jõhvi zones.
A compositional geostatistical workflow was applied to legacy geochemical data. Exploratory tools—such as box plots, concentration maps, and Q–Q plots—were used on raw data, while centred log-ratio (clr) transformation improved signal coherence and interpretative clarity. Clr-based maps, PCA, and heat maps help reduce artefacts caused by heterogeneous sampling, analytical variability, and mismatched neighbouring map sheets, enabling more reliable spatial interpretation.
Lithologies from historical drill cores, often unclassified or inconsistently documented, were re-evaluated using major-element data, with trace-element data reassigned based on the Tallinn–Alutaguse–Jõhvi basement-domain architecture. Combining these geochemical reclassifications with gravity and magnetic data refines the petrotectonic framework of NE Estonia and strengthens links to South Svecofennian and Bergslagen mineral systems.
Collectively, these geochemical, geostatistical, and geophysical findings offer an updated metallogenic model and highlight new targets for critical raw materials within the Horizon Europe DEXPLORE program.
