Janne Blichert-Toft

How mining has shaped long-term economic and political landscapes across Europe and the Mediterranean remains poorly understood, largely because archaeological evidence is spatially fragmented and ore sources are difficult to trace from atmospheric lead (Pb) records. Here, we compile Pb isotope data from environmental archives and introduce the Environmental Match Intensity Index (EMII), a metric applied to peat records to track Pb–silver (Ag) ore-supply patterns and relative changes in the integrated mining-related atmospheric Pb signal over six millennia. EMII reveals an early mining signal centered on Laurion (Greece) during the Late Neolithic/Chalcolithic, followed by Bronze Age expansion structured by maritime routes linking the Cyclades, the Troad, and Anatolian coasts. From the Iron Age onward, our results challenge the conventional Iberian-centered mining model and instead reveal a polycentric and multimodal organization rooted in west-central European districts interconnected through major fluvial corridors and complementary terrestrial and maritime routes. EMII reaches its first major peak during the Early Roman period, declines during Late Antiquity and the Early Middle Ages, and rises again from the High Middle Ages onward. Despite these temporal fluctuations, the overall continental distribution of the contributing mining regions remains broadly stable. By connecting environmental archives with mining, transport, and urban demand, this framework provides a scalable approach for reconstructing the long-term organization of metal production and circulation and their contribution to anthropization processes across different chrono-cultural periods and geographical settings.

Understanding how processes of magma genesis and magma differentiation control and modify the chemical composition of erupted lavas from the geochemical measurements of the latter is an under-constrained inverse problem, as there is only one known parameter—the measured composition of the erupted lava—but two unknown parameters—the chemical composition and lithology of the source before melting and how melting, crystallization, and melt–rock interactions act to alter the lava en route to the surface. In this invited contribution, we review nearly seven decades of scientific research that demonstrate the potential of U and Th decay series measurements for unraveling the complexities of oceanic magmatism. We review the underlying nuclear theory, geochemical principles, and application of the ²³⁸U, ²³⁵U, and ²³²Th decay series for (i) defining the timescales of magma genesis during decompression mantle melting, (ii) establishing the timescales of magma recharge and magma degassing, and (iii) determining the eruption ages of oceanic Quaternary volcanism.

The Lomagundi–Jatuli Event (LJE), Earth’s most pronounced and prolonged positive carbon isotope excursion, followed the Great Oxidation Event and remains enigmatic in origin. We present a Pb–Pb isochron age of 2,194 ± 5 Ma for black shales from the Francevillian FB Formation, Gabon—an LJE type locality—coinciding with the emplacement of the Large Igneous Province that gave rise to the extensive Birimian–Eburnean orogenic segment. This orogeny produced very large volumes of juvenile crust in the form of oceanic plateau basalts that were eventually reworked through subduction and collisions. These processes released substantial volcanic CO ₂ into the ocean–atmosphere system, disrupting the carbon and oxygen cycles for 100 to 200 My. Volcanic outgassing likely outpaced alkalinity production from weathering, leading to an increase in the δ ¹³ C of sedimentary carbonates. Reanalysis of global δ ¹³ C–δ ¹⁸ O datasets reveals a previously unrecognized dual bimodality, attributed here to episodic volcanic degassing and subsequent oceanic carbonate saturation. Weathering of emergent crust enhanced nutrient fluxes, driving primary productivity and organic carbon burial. We further propose that volcanic CO ₂ emissions modulated the Dole Effect by shifting the balance between terrestrial and marine photosynthetic oxygen production, altering atmospheric oxygen isotope ratios independently of climate. These processes collectively drove the δ ¹³ C excursion of the LJE and may have fostered conditions conducive for early eukaryotic evolution.

Understanding how processes of magma genesis and magma differentiation control and modify the chemical composition of erupted lavas from the geochemical measurements of the latter is an under-constrained inverse problem as there is only one known parameter – the measured composition of the erupted lava – but two unknown parameters – the chemical composition and lithology of the source before melting and how melting, crystallization, and melt-rock interactions act to alter the lava en route to the surface. In this invited contribution, we review nearly seven decades of scientific research that demonstrate the potential of U and Th decay series measurements for unraveling the complexities of oceanic magmatism. We review the underlying nuclear theory, geochemical principles, and application of the ²³⁸U, ²³⁵U, and ²³²Th decay series for (i) defining the timescales of magma genesis during decompression mantle melting, (ii) establishing the timescales of magma recharge and magma degassing, and (iii) determining the eruption ages of oceanic Quaternary volcanism.

Local types of coinage testify to the emerging use of silver in the Balkan interior, possibly related to abundant ore deposits in the region. Here, we present Pb isotope data for silver coins minted by local tribes and settlements (anepigraphic coins attributed to the Derrones/Laeaei, Damastion, Pelagia, Kings of Paeonia) between the 5th and 3rd centuries BCE. For comparison, we analysed coinage of the potential Greek emporia Dyrrhachium and Apollonia for their main element and Pb-Ag isotope compositions. Statistical data evaluation demonstrates close material connections between coins from the Balkan interior and identify a predominantly local raw material provenance. The majority of Damastion’s issues defines a tight cluster fitting Strabo’s (VII.7.8) account that the settlement possessed nearby silver mines in the Balkan interior. Novobërdë/Novo Brdo (Kosovo) can be plausibly hypothesised among the available reference data to have been one of the main ore districts supplying the mint. Mixing is evident for coins from the Kings of Paeonia and coinage attributed to the Derrones/Laeaei. Virtually identical end-members suggest that Paeonian regal coinage recycled tribal issues with contribution of metal obtained from Damastion’s hypothesised mines. Contemporaneous coinage struck by Dyrrhachium as well as end-members calculated for Thasos and the Macedon kingdom (Albarede et al. in Bullion mixtures in silver coinage from ancient Greece and Egypt, J Archaeol Sci 162:105918, 2024a) signal metal sourced from the Balkans, presumably the Macedonian/Paeonian border area. Comparison of data from Greek city-states and coinage issued by Apollonia and Dyrrhachium for the Romans demonstrates a change in the type and origin of raw materials and bullion composition, indicating a shift in monetary customs and possibly metal production technology.