Publications by Year: 2021

2021
Ross J, Voudouris P, Melfos V, Vaxevanopoulos M, Soukis K, Merigot K. {The Lavrion silver district: Reassessing its ancient mining history}. Geoarchaeology. 2021:1–26.Abstract
Lavrion was an important silver mining district in the ancient world, exploited almost continuously from the fourth millennium BC. Its mining history is central to understanding the availability of silver, lead and copper in Greece and the Aegean through the Bronze age. This history is also relevant to the phenomenal rise of Athens in the 5th century BC. Our reassessment of the mineralisation and ancient mining history at Lavrion provides a clearer understanding of its capacity to generate wealth and the scale of its impact on Athens. Integration of new geochemical and geological data with existing information has produced outcomes that help address these two issues. Foremost is the contrasting character of mineralisation at the upper 'first' and lower 'third' contacts and their marked differences in silver content, spatial distribution and supergene alteration. Discovery of the concealed, bonanza mineralisation of the third contact at Kamariza, possibly early in the 5th century BC, followed about 3000 years of mining, which appears to have been largely restricted to discontinuous, low-grade mineralisation at the first contact. Undoubtedly, this later discovery had enduring impacts on Lavrion and Athens, and it most likely funded the trireme fleet, which brought victory over the Persians at Salamis in 480 BC.
Koutsovitis P, Soukis K, Voudouris P, Lozios S, Ntaflos T, Stouraiti C, Koukouzas N. {The Late Cretaceous magmatic arc of the south Aegean: Geodynamic implications from petrological and geochemical studies of granitoids from Anafi island (Cyclades–Greece)}. International Geology Review [Internet]. 2021;00:1–24. WebsiteAbstract
In the Aegean region (Cyclades–Greece), a large part of the Island of Anafi consists of exhumed high-grade metamorphic sequences (amphibolites, serpentinites and metasediments) that have been intruded by Late Cretaceous intermediate and felsic granitoids. These correspond to I-type arc-related rocks, displaying calc-alkaline geochemical affinities. Variability in their petrographic features, mineral composition and geochemistry is assigned to differentiation processes that mostly involved plagioclase and/or K-feldspar, and to a lesser extent amphibole and biotite. Mineral chemistry and geochemical results suggest that the Anafi granitoids are highly comparable with the Late Cretaceous granitoid intrusive rocks from East Crete and Donousa island. The amphibole and zircon saturation thermometry yields relatively moderate temperature crystallization conditions ($\sim$790°C) for the intermediate granitoids and lower for the felsic granitoids ($\sim$630°C). Geobarometric calculations based upon the chemistry of magnesiohornblende, as well as the normative (Qz), (Ab) and (Or) contents clearly point to shallow intrusion conditions ($\sim$2.0–6.5 kbar), corresponding to an estimated depth of crystallization of $\sim$12 ± 4 km. The thrust sheets that overly the Palaeogene flysch in Anafi (metasediments with serpentinized peridotites, amphibolites and metabasites), constitute a subducted and metamorphosed oceanic sequence. These metamorphic units likely represent a part of the Pindos–Cycladic Blueschist Unit domain that was subducted at an earlier pre-Campanian stage. In the hydrated mantle wedge, incorporation of shallow level granitoids within metamorphic units was likely facilitated via corner flow intrusion mechanisms. Following the intrusion, the granitoid rocks were exhumed in a syn-convergent setting, along with the metamorphic thrust sheets, by continuous underplating of more external units, thus, escaping penetrative ductile deformation.
Voudouris P, Melfos V, Mavrogonatos C, Photiades A, Moraiti E, Rieck B, Kolitsch U, Tarantola A, Scheffer C, Morin D, et al. {The Lavrion Mines : A Unique Site of Geological and}. Minerals. 2021;11:76.Abstract
The Lavrion area corresponds to the western part of the Attic-Cycladic metamorphic belt, in the back-arc region of the active Hellenic subduction zone. Between the Eocene and the Miocene, metamorphic rocks (mainly marbles and schists) underwent several stages of metamorphism and deformation due to collision and collapse of the Cycladic belt. Exhumation during the Miocene was accommodated by the movement of a large-scale detachment fault system, which also enhanced emplacement of magmatic rocks, leading to the formation of the famous Lavrion silver deposits. The area around the mines shows the stacking of nappes, with ore deposition mainly localized within the marbles, at marble-schist contacts, below, within, or above the detachment. The Lavrion deposit comprises five genetically-related but different styles of mineralization, a feature never observed in another ore deposit elsewhere, containing the highest number of different elements of any known mining district. The local geology, tectonic, and magmatic activity were fundamental factors in determining how and when the mineralization formed. Other key factors, such as the rise and the fall of sea level, which resulted from climate change over the last million years, were also of major importance for the subsequent surface oxidation at Lavrion that created an unmatched diversity of secondary minerals. As a result, the Lavrion deposit contains 638 minerals of which Lavrion is type-locality for 23 of them, which is nearly 12% of all known species. Apart from being famous for its silver exploitation, this mining district contains more minerals than any other district on Earth.