Ervedosa Mine (Tuela Mine), Ervedosa, Vinhais, Bragança, Portugali

Regional Level Types
Ervedosa Mine (Tuela Mine)	Mine
Ervedosa	Civil Parish
Vinhais	Municipality
Bragança	District
Portugal	Country

Sn-As mine (1906/1969)
Other official documents also contain the discovery and registration of the ore deposit by different explorers, with the earliest date of registration being in 1873 (Fernandes 2010). Since this date, the ore deposit was registered 18 more times by different explorers.

- First period:
Everdosa Mine - mining concessions:
No. 631 Alto do Vale da Veiga (Sn), registerd on 05-11-1914 (*)
No. 493 Pereiro (Sn), registerd on 24-12-1909 (*)
No. 492 Borralheira (Sn), registerd on 23-12-1909 (*)

- Second period:
Everdosa Mining Field (CM31) registered on 05-05-1938

(*) Merged in the Everdosa Mining Field in 1938.

The first references to the tinny deposit of Ervedosa date back to 1857. After a long series of new registrations in 1908 the first mining concession (mina do Alto do Pereiro) was establised and allocated to the Belgian co. Société des Mines d'Etain d'Ervedosa.
The mine was exploited for tin and arsenic with some initial preparatory and prospecting underground works. It was also built a washing plant on the right bank of the river Tuela. However, in 1917, that company stoped the mining operations, which were then resumed in 1920, but now by the English co. Ervedosa Tin Mines. Under this administration was built a new washing plant on the left bank of the River Tuela as complement to the existing one, however, in 1927, the company stoped the exploration.
The mine was acquired by some of its former employees and the operations restarted in 1928. In 1938 the mining concessions were merged in with the Couto Mineiro de Ervedosa (Everdosa Mining Field), already a major producer of concentrates of cassiterite.
Between 1939 and 1965, the mine worked on continuous mining having been removed from the Ervedosa mine, also called mine Tuela, about 6,000 tons of tin and the same amount of arsenic oxide. According to existing registers, there was a depletion of mineralization since 1959. Between 1958 and 1969 the operation was made predominantly in the open pits and simultaneously in the alluvium of the Tuela River, where cassiterite levels could reach about 4 kg per tonne.
The mines closed definitively in 1969.
In 2007 the co. Mining Technology Investments has done some research and prospecting studies.
Portuguese version summarized and adapted to English by RN, "O Passado Mineiro e o Presente, na Região de Rebordelo, Ervedosa e Murçós", Elisa Preto, Paulo Favas e Nuno Figueiredo, 2008.


The geological context of the site indicates a rich cassiterite (SnO2) deposit, which was subject to mining in the 20th century. Some ancient mining and ore processing stone tools were recovered during the 20th century mining operations, namely one hammer, one pounder, one flat anvil and five small tools used both as pounders and crushing anvils, evidencing Prehistoric mining activities. XRF and SEM-EDS chemical analyses were performed on primary and secondary cassiterite samples from the mining site, demonstrating the abundance and chemical heterogeneity of the tin (Sn) ores. The stone tools can be ascribed to Bronze Age or, at the latest, Early Iron Age (2nd millennium to first half of 1st millennium BCE) by comparison with similar tools from other Iberian and European archaeological contexts.

Other Regions, Features and Areas containing this locality

References