Mineral Inventory of the Algares 30-Level Adit, Aljustrel Mine, Iberian Pyrite Belt, Portugal
Mining activity in Algares (Aljustrel Mine, Portuguese sector of the Iberian Pyrite Belt, IPB) stems prior to Roman times. As the orebody is vertical and relatively thin, mining was carried out mainly along underground adits (galleries). Nowadays, the deposit is considered exhausted and the area is...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-09-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/10/10/853 |
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| author | Teresa P. Silva João X. Matos Daniel De Oliveira João P. Veiga Igor Morais Pedro Gonçalves Luís Albardeiro |
| author_facet | Teresa P. Silva João X. Matos Daniel De Oliveira João P. Veiga Igor Morais Pedro Gonçalves Luís Albardeiro |
| author_sort | Teresa P. Silva |
| collection | DOAJ |
| description | Mining activity in Algares (Aljustrel Mine, Portuguese sector of the Iberian Pyrite Belt, IPB) stems prior to Roman times. As the orebody is vertical and relatively thin, mining was carried out mainly along underground adits (galleries). Nowadays, the deposit is considered exhausted and the area is being rehabilitated for a different use. The Algares +30 level adit intersects two volcanic units of the IPB Volcano-Sedimentary Complex. The massive sulphide and related stockwork zone are hosted by the <i>Mine Tuff</i> volcanic unit and are exposed in the walls of the gallery, showing intense hydrothermal alteration. Along the mine adit, the geological sequence is affected by strong oxidation and supergene alteration, giving rise to the formation of secondary minerals through the oxidation of the sulphides. The most common minerals found were melanterite (FeSO<sub>4</sub>·7H<sub>2</sub>O) and chalcanthite (CuSO<sub>4</sub>·5H<sub>2</sub>O), forming essentially massive or crystalline aggregates, ranging from greenish to bluish colours. Melanterite from the walls revealed to be Cu-rich by opposition to that from stalactites/stalagmites formed below the old ore storage silo revealing the low-copper-grade ores exploited underground. The mineralogy of the efflorescent salts was used to ascertain the processes involved in their formation, and moreover, the inventory of minerals is presented, as well as their principal characteristics. |
| first_indexed | 2024-03-10T16:00:41Z |
| format | Article |
| id | doaj.art-4d79e41fc6a643a4b647aa635f8d0777 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T16:00:41Z |
| publishDate | 2020-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-4d79e41fc6a643a4b647aa635f8d07772023-11-20T15:16:36ZengMDPI AGMinerals2075-163X2020-09-01101085310.3390/min10100853Mineral Inventory of the Algares 30-Level Adit, Aljustrel Mine, Iberian Pyrite Belt, PortugalTeresa P. Silva0João X. Matos1Daniel De Oliveira2João P. Veiga3Igor Morais4Pedro Gonçalves5Luís Albardeiro6LNEG (National Laboratory for Energy and Geology), Mineral Resources and Geophysics Research Unit, Estrada da Portela, Apartado 7586, 2610-999 Amadora, PortugalLNEG (National Laboratory for Energy and Geology), Mineral Resources and Geophysics Research Unit, Bairro de Val d’Oca, Apartado 14, 7601-909 Aljustrel, PortugalLNEG (National Laboratory for Energy and Geology), Mineral Resources and Geophysics Research Unit, Estrada da Portela, Apartado 7586, 2610-999 Amadora, PortugalCENIMAT/I3N (Materials Research Centre), Materials Science Department, Faculty of Sciences and Technology, NOVA University of Lisbon, 2829-516 Caparica, PortugalLNEG (National Laboratory for Energy and Geology), Mineral Resources and Geophysics Research Unit, Bairro de Val d’Oca, Apartado 14, 7601-909 Aljustrel, PortugalLNEG (National Laboratory for Energy and Geology), Mineral Resources and Geophysics Research Unit, Bairro de Val d’Oca, Apartado 14, 7601-909 Aljustrel, PortugalLNEG (National Laboratory for Energy and Geology), Mineral Resources and Geophysics Research Unit, Bairro de Val d’Oca, Apartado 14, 7601-909 Aljustrel, PortugalMining activity in Algares (Aljustrel Mine, Portuguese sector of the Iberian Pyrite Belt, IPB) stems prior to Roman times. As the orebody is vertical and relatively thin, mining was carried out mainly along underground adits (galleries). Nowadays, the deposit is considered exhausted and the area is being rehabilitated for a different use. The Algares +30 level adit intersects two volcanic units of the IPB Volcano-Sedimentary Complex. The massive sulphide and related stockwork zone are hosted by the <i>Mine Tuff</i> volcanic unit and are exposed in the walls of the gallery, showing intense hydrothermal alteration. Along the mine adit, the geological sequence is affected by strong oxidation and supergene alteration, giving rise to the formation of secondary minerals through the oxidation of the sulphides. The most common minerals found were melanterite (FeSO<sub>4</sub>·7H<sub>2</sub>O) and chalcanthite (CuSO<sub>4</sub>·5H<sub>2</sub>O), forming essentially massive or crystalline aggregates, ranging from greenish to bluish colours. Melanterite from the walls revealed to be Cu-rich by opposition to that from stalactites/stalagmites formed below the old ore storage silo revealing the low-copper-grade ores exploited underground. The mineralogy of the efflorescent salts was used to ascertain the processes involved in their formation, and moreover, the inventory of minerals is presented, as well as their principal characteristics.https://www.mdpi.com/2075-163X/10/10/853efflorescent mineralsadit wallsstalactites/stalagmitesmineral inventoryAlgaresIberian Pyrite Belt mine |
| spellingShingle | Teresa P. Silva João X. Matos Daniel De Oliveira João P. Veiga Igor Morais Pedro Gonçalves Luís Albardeiro Mineral Inventory of the Algares 30-Level Adit, Aljustrel Mine, Iberian Pyrite Belt, Portugal Minerals efflorescent minerals adit walls stalactites/stalagmites mineral inventory Algares Iberian Pyrite Belt mine |
| title | Mineral Inventory of the Algares 30-Level Adit, Aljustrel Mine, Iberian Pyrite Belt, Portugal |
| title_full | Mineral Inventory of the Algares 30-Level Adit, Aljustrel Mine, Iberian Pyrite Belt, Portugal |
| title_fullStr | Mineral Inventory of the Algares 30-Level Adit, Aljustrel Mine, Iberian Pyrite Belt, Portugal |
| title_full_unstemmed | Mineral Inventory of the Algares 30-Level Adit, Aljustrel Mine, Iberian Pyrite Belt, Portugal |
| title_short | Mineral Inventory of the Algares 30-Level Adit, Aljustrel Mine, Iberian Pyrite Belt, Portugal |
| title_sort | mineral inventory of the algares 30 level adit aljustrel mine iberian pyrite belt portugal |
| topic | efflorescent minerals adit walls stalactites/stalagmites mineral inventory Algares Iberian Pyrite Belt mine |
| url | https://www.mdpi.com/2075-163X/10/10/853 |
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