Panasqueira Mines, Portugali

Regional Level Types
Panasqueira Mines	Group of Mines (Active)
Portugal	Country

Mine Information: A large tin-tungsten mine made up of multiple concessions that started production in 1898. Mining is in gently dipping stacked quartz veins that lead into mineralized wolfram-bearing schist. The mineralized zone has dimensions of approximately 2,500 m in length, varying in width from 400 m to 2,200 m, and continues to at least 500 m in depth.

Originally the longwall method or a variant with partial filling was used, but in 1986 it was changed to room-and-pillar based on an analysis of geological and geomechanical characteristics of the rock mass.

Access to the mine's main levels is by a 2.5 m x 2.8 m decline from the surface at a 14% grade. The main levels consist of a series of parallel drives that are spaced 100 m apart and which provide access to the ore passes for rail transport, and connect with ramps for movement of drilling and loading equipment.

Blocks of ore are laid out initially in 100 m x 80 m sections by driving 5 m wide tunnels, 2.2 m high. Similar crosscuts are then set off at right angles to create roughly 11 m by 11 m pillars, which are ultimately trimmed to 3 m by 3 m, providing an extraction rate of 84%. Blasted ore is loaded from the stopes by a fleet of LHDs (rubber-tired low profile loaders), tipping into 1.8 m-diameter bored raises connecting to the main level boxes. Rail haulage with trolley locomotives is used to transport the ore to the shaft on Level 3, and to the 900 t-capacity main ore pass on Level 2 that provides storage for the 190 metric ton/hour jaw crusher located at the 530 m-level.

Geology:
Panasqueira granite intrudes Precambrian marine shales, greywackes, and sandstones. Shales are converted into biotite-cordierite-andalusite hornfelses near the granite contact. Irregular barren quartz masses were formed in shales (quartz segregation lenses) during Hercynian (the geologic mountain-building event caused by the Late Paleozoic continental collision between Euramerica and Gondwana to form the supercontinent of Pangaea) regional metamorphism. The Panasqueira muscovite-albite leucogranite batholith evolves upwards into a quartz-greisen cupola overlain by a quartz cap, from which related quartz veins (stockscheider) penetrate into the shales. Later subhorizontal mineralized veins follow these quartz veins.

Four stages of mineralization are known:
1) Oxide-silicate stage (280-320 °C): ferberite, cassiterite in quartz veins, arsenopyrite, topaz, muscovite, and tourmaline
2) Sulfide stage: arsenopyrite, pyrite, pyrrhotite, chalcopyrite, sphalerite, stannite, etc.
3) Pyrrhotite alteration stage
4) Carbonate stage: calcite and dolomite, minor sulfides

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The industrial mining center commonly known as "Panasqueira Mines" extends over a vast area covered by the Panasqueira and Vale da Ermida Mining Fields, with a total area around 20.5 km².

Although the current mining is concentrated in about a dozen concessions, all others are the object of a systematic study for the evaluation of reserves and determination of their economic potential.

Mineralized zones: Décio Thadeu (*), supported by morphological, mineralogical and tectonic data, presented a classification that until today has been adopted and confirmed by the mining works executed in them. According to this author, the areas are as follows:

a) Panasqueira and Barroca Grande
b) Corga Seca, Alvoroso, Veia Branca and Giestal
c) Lomba da Cevada
d) Rebordões and Seladinho
e) Fonte das Lameiras
f) Vale das Freiras and Vale da Ermida
g) Cabeço do Pião

1 - Panasqueira Mining Field – Castelo Branco District
(concession no. - name - registered on - locality)
316 – Ponte Masso - 07-04-1900 – Aldeia de São Francisco de Assis – Covilhãt
340 – Corga Seca - 26-11-1901 – Aldeia de São Francisco de Assis – Covilhã
366 – Salada Coca - 14-09-1903 – Aldeia de São Francisco de Assis - Covilhã
367 – Barroca Grande - 15-09-1903 – Aldeia de São Francisco de Assis - Covilhã
378 – Gambão - 05-05-1904 – Aldeia de São Francisco de Assis - Covilhã
380 – Alvaroso - 09-05-1904 – Aldeia de São Francisco de Assis - Covilhã
381 – Vale de Carvalhos - 10-05-1904 – Aldeia de São Francisco de Assis - Covilhã
399 – Terreno de Manuel Gil - 16-03-1906 – Aldeia de São Francisco de Assis – Covilhã
721 – Fontainhas - 21-11-1916 – Aldeia de São Francisco de Assis - Covilhã
844 – Giestal - 02-04-1919 – Aldeia de São Francisco de Assis – Covilhã
990 – Chiqueiro no. 2 - 03-03-1921 – Aldeia de São Francisco de Assis - Covilhã
1139 – Sítio dos Cambões - 12-05-1922 – Aldeia de São Francisco Assis - Covilhã
1565 – Bodelhão no. 1 - 12-11-1926 – Aldeia de São Francisco Assis - Covilhã
1566 – Bodelhão no. 2 - 12-11-1926 – Aldeia de São Francisco Assis - Covilhã
1567 – Bodelhão no. 3 - 12-11-1926 – Aldeia de São Francisco Assis – Covilhã
3088 – Parada do Bodelhão - 31-03-1956 – Aldeia de São Francisco Assis - Covilhã
3089 – Ribeiro da Videira no. 1 - 31-03-1956 – Aldeia de São Francisco Assis - Covilhã
3090 – Ribeiro da Videira no. 2 - 31-03-1956 – Aldeia de São Francisco Assis – Covilhã
3108 – Guinchão - 17-05-1956 – Aldeia de São Francisco Assis - Covilhã
3109 – Ribeiro Dianteiro - 17-05-1956 – Aldeia de São de Francisco Assis - Covilhã
3196 – Barroco do Carneiro - 20-02-1958 – Aldeia de São Francisco de Assis – Covilhã
1568 – Panasqueira no. 4 - 12-11-1996 - São Jorge da Beira (Cebola) - Covilhã
2347 – Madurrada - 08-01-1949 - São Jorge da Beira (Cebola) - Covilhã
2425 – Cova da Cruz - 29-09-1949 - São Jorge da Beira (Cebola) - Covilhã
2526 – Torgais - 24-02-1950 - São Jorge da Beira (Cebola) - Covilhã
253 – Panasqueira - 31-05-1894 – São Jorge da Beira (Cebola) - Covilhã
3098 – Cambões de Baixo - 03-05-1956 - São Jorge da Beira (Cebola) - Covilhã
3107 – Barroco dos Carias - 17-05-1956 - São Jorge da Beira (Cebola) - Covilhã
317 – Panasqueira no. 2 - 09-04-1900 – São Jorge da Beira (Cebola) - Covilhã
318 – Panasqueira no. 3 - 10-04-1900 – São Jorge da Beira (Cebola) - Covilhã
319 - Vale da Ermida - 11-04-1900 - São Jorge da Beira (Cebola) - Covilhã
3223 – Madurrada no. 2 - 12-07-1958 – São Jorge da Beira (Cebola) – Covilhã
470 – Vale do Rebordão - 04-09-1908 – São Jorge da Beira (Cebola) - Covilhã
695 – Barroco Fundo (Cebola no. 1) - 10-04-1916 – São Jorge da Beira (Cebola) - Covilhã
900 – Vale da Ermida no. 4 - 18-11-1919 – São Jorge da Beira (Cebola) - Covilhã
980 – Lomba do Muro - 02-12-1920 – São Jorge da Beira (Cebola) – Covilhã
987 – Curral dos Capados - 26-02-1981 – São Jorge da Beira (Cebola) – Covilhã
CM15 – Panasqueira – 23-09-1927 – São Jorge da Beira (Cebola) – Covilhã
255 – Cabeço do Pião - 11-10-1894 – Barroca - Fundão
1036 – Terras do Muro - 07-05-1921 – Barroca - Fundão
1207 – Cebolal ou Resteira - 28-07-1922 – Barroca – Fundão
955 – Costa Meal - 02-06-1920 – Silvares - Fundão
1212 – Costa Meal no. 1 - 03-08-1922 – Silvares – Fundão

2 - Vale da Ermida Mining Field – Coimbra District
(concession no. - name - registered on - locality)
640 – Fonte das Lameiras - 14-01-1915 – Dornelas do Zêzere – Pampilhosa da Serra - Coimbra
3186 - Roçadas - 31-12-1957 – Dornelas do Zêzere – Pampilhosa da Serra - Coimbra
986 - Vale da Ermida no. 2 - 25-02-1921 – Unhais o Velho – Pampilhosa da Serra – Coimbra
988 – Curral dos Capados no. 2 - 28-02-1921 – Unhais o Velho – Pampilhosa da Serra - Coimbra
989 – Chiqueiro no. 1 - 28-02-1921 – Unhais o Velho – Pampilhosa da Serra - Coimbra
3185 – Eiradas - 31-12-1957 – Unhais o Velho – Pampilhosa da Serra - Coimbra
3187- Portela no. 3 - 31-12-1957 – Unhais o Velho – Pampilhosa da Serra - Coimbra
CM55 - Vale da Ermida - 04-03-1961 – Unhais o Velho – Pampilhosa da Serra – Coimbra



(*) Thadeuite: TL Panasqueira, named for Décio Thadeu (1919-1995), Professor of Geology, Instituto Superior Técnico, Lisbon, Portugal.

Minerals
The Panasqueira mines have produced, and still produce, the best ferberite, arsenopyrite and fluorapatite specimens in existence.

Localities in this Region

Other Regions, Features and Areas that Intersect

References