Minas de Ojos Negros

Useful Information

Location:	Between the municipalities of Setiles and Ojos Negros. (40.715818, -1.546358)
Open:	no restrictions. [2023]
Fee:	free. [2023]
Classification:	Iron Mine
Light:	n/a
Dimension:
Guided tours:	self guided
Photography:	allowed
Accessibility:	no
Bibliography:	C. Polo Cutando (1999): The metallurgy of iron during the time in Sierra Menera celtiberica (Guadalajara, Teruel) Symposium IV Celtiberos. Economy. Zaragoza :191-201.
Address:	Ayuntamiento de Ojos Negros, Plaza Mayor, 10, 44313, Ojos Negros (Teruel), Tel: +34-978865257, Fax: +34-978865286. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

1903	Sierra Menera Mining Company was formed by Basque entrepreneurs Eduardo Aznar and Ramon de Sota.
1907	mines connected to the railway.
1986	mines closed.
2007	submitted to the UNESCO WHL tentative list.

Geology

Ordovician and Silurian basement rocks contain Mg-Fe ores. Quartzites and graywackes of Early Ordovician age are overlain by a Late Ordovician carbonates, known as the El Pobo limestones, deposited in an epicontinental sea after Caledonian tectonism. The orebodies are strata-bound and preferentially located on the flanks of the anticline. They are typically 1 m to 10 m thick, in some locations the entire 120 m thick host dolostone sequence was replaced by Mg-Fe carbonates. The ores are of metasomatic hydrothermal origin, by the influx of hot Fe-Mg rich fluids under acid and reducing conditions. The upper part was oxidized during late Pliocene karstification, which also created mogotes, karren, caves, shafts, and iron ore rich residuals.

Description

The Antiguas minas de Ojos Negros (Antigue mines of Ojos Negros) are several huge open cast mines and adjacent slag heaps. They were mined from the early 20th century and were closed in 1986. However, mining actually started in Roman times, that's why they are called "antique" mines. The Sierra Menera is a 31 km long mountain range and has rich iron ore deposits which were exploited since ancient Celtiberian, during Roman times, and until the late 20th century.

The Compañía Minera de Sierra Menera S. A. (Sierra Menera Mining Company) was formed by Basque entrepreneurs Eduardo Aznar and Ramon de Sota in 1903. They started building a 204 km long railway line to bring the iron ore to the furnaces and harbor of Sagunto, where they also owned a blast furnace. It was the longest private company-owned railway line in Europe at that time and wa completed in 1907. They built a pelletizing plant and a long jetty in the 1970s. In 1984 the Sagunto ore-processing facilities closed and in 1986 the Sierra Menera mining company went bankrupt. As a result the mines were closed.

The site is not a show mine, although it was submitted to the UNESCO WHL tentative list. It's possible to see the open casts and slag heaps on a walking trail, and there is a small mining museum in Ojos Negros.