Former iron ore mine site at Segré retaining a metal headframe, a descenderie entrance, and masonry arches from a former aerial ore conveyor, now partly incorporated into civic and commercial uses.
The puits de l'Oudon at Segré, now part of Segré-en-Anjou Bleu, is the former extractive site of the concession des Mines de fer de l'Oudon, one of the four magnetite ore concessions that formed the Haut-Anjou iron basin. The concession was authorised on 3 January 1875 for the Société des Hauts-Fourneaux de Denain, extending across the communes of Segré, Sainte-Gemmes-d'Andigné, and la Chapelle-sur-Oudon. From 1874 small gallery mines had been opened on the south bank of the Oudon river at the lieux-dits Vaududon and Minguet.
When the modern carreau was opened in 1907 it took the distinctive form of a descenderie inclined at 36 degrees. From 1881 the Oudon concession joined the basin-wide company, ultimately becoming part of the Société des Mines de Fer de Segré in 1911. Before the crisis of 1929 the carreau de l'Oudon produced approximately 960,000 tonnes of magnetite.
Depressed prices and unsold stock caused closure in 1934. The surviving structures of the carreau — a metal headframe, the descenderie entrance, buildings from 1911 to 1916, and the masonry arches of a former aerial ore conveyor — remain on the site, which is now in partial civic and commercial use. The laboratory building of 1912, constructed in reinforced concrete with a flat roof at the lieu-dit Baugé, has been converted into a centre médico-social.
The bassin ferrifère du Haut-Anjou is formed within Ordovician strata of the Segré area in Maine-et-Loire, in which magnetite ore beds occur within Armorican sandstone and schist. The concession des Mines de fer de l'Oudon was authorised on 3 January 1875 and attributed to the Société des Hauts-Fourneaux de Denain at Anzin, extending across the communes of Segré, Sainte-Gemmes-d'Andigné, and la Chapelle-sur-Oudon. As early as 1874, two small exploitations had been opened from galleries cut into the hillside on the south bank of the Oudon river at the lieux-dits Vaududon and Minguet.
In 1881 the concession de l'Oudon joined the other three Anjou concessions — La Ferrière, les Aulnais, and Le Bois — that had grouped in 1878 to form the Société des Mines de Fer de l'Anjou et des Forges de Saint-Nazaire, with Louis-Paul Davy as director. After the faillite of this company and subsequent reconstitutions, the Société des Mines de Fer de Segré was formally constituted on 8 May 1911. When the principal modern extraction site at the Oudon was opened in 1907 it presented in the distinctive form of a descenderie, a plan incliné at 36 degrees, rather than a vertical shaft.
This descenderie reached the magnetite layers at approximately minus 250 metres. The construction of the surface buildings at the carreau de l'Oudon is dated from the archives of the Mines de Fer de Segré to between 1911 and 1916; the programme included a railway connection to the gare de Segré and, after 1914, an aerial ore conveyor. At the lieu-dit Baugé, on the north bank of the Oudon, the laboratory was fitted out in 1912 using the structure of the former moulin des Aulnais, with the adjacent administrative offices of the same period.
From 1907 to the closure in 1934, the carreau de l'Oudon produced approximately 960,000 tonnes of magnetite in total. Production was routed first by cart and later by aerial conveyor directly to the gare de Segré. The depressed prices caused by the 1929 economic crisis, combined with the specific pressure of the German metallurgical crisis and accumulated unsold stock, led to the definitive closure of the carreau de l'Oudon in 1934.
After 1934, the Société des Mines de Fer de Segré concentrated exclusively on the Bois and Aulnais concessions. The buildings of the carreau de l'Oudon — the metal headframe, the descenderie entrance, an atelier in stone rubble masonry with a metal frame, a further industrial building identified as the recette and triage building, and a bureau to the north-west — together with the masonry arch piers that supported the aerial ore conveyor, remain on the site today. The conveyor arch elements visible as preserved structures in a jardin public form a distinctive legacy of the pre-closure infrastructure.
At the lieu-dit Baugé, the laboratory and administrative building — long buildings in reinforced concrete with flat roofs — have been restored and converted: the laboratory into a centre médico-social and the administrative building into a residential dwelling. The cité ouvrière adjacent to the Baugé site, begun before 1914 and developed through the 1920s, has also survived. A workers' cité on the rue de la Paix in Segré and the cité Baugé, more commonly known as the cité des mines, together represent the residential infrastructure of the Oudon concession.
The 1931 administrative building constructed in concrete at the site, together with the laboratory, exemplify the reinforced concrete architecture of the period.
