| Quenast quarry | |
| Location: | Quenast, Belgium |
| Coordinates: | 50.6647°N 4.1556°W |
| Type: | Porphyry quarry |
| Owner: | Sagrex of Heidelberg Materials |
| Pushpin Map: | Belgium |
| Pushpin Map Caption: | Location in Belgium |
The Quenast quarry (fr|Carrière de Quenast) or Porphyry quarries of Quenast is a historic porphyry deposit in Belgium and Europe's largest open-pit quarry. Porphyry has been mined from the quarry as an important source for construction since the 17th century and was traditionally used to make Belgian cobblestones for city streets.[1]
In the village of Quenast, from Brussels and within Rebecq, Walloon Brabant, the quarry covers and reaches a depth of .
The porphyry material, formed beneath the tertiary rocks in Brabant during the Silurian period, is of volcanic origin and known for its extreme toughness.[2] [3] Belgian porphyry was traditionally made into cobblestones or paving stone.[4] This material was used for paving and road construction, with exports to cities across Europe and globally, including heavy use in the streets of Paris.[5] In 1705, the States of Brabant constructed the Brussels-Mons road with stones sourced from the quarry, according to records.[6]
The material extracted from the quarry was moved along a railway, linking with the main line at Tubize.[7]
In 1844, entrepreneur Joseph-Emmanuel Zaman began unifying the porphyry quarries under a single ownership, transforming them into one of Belgium's most significant industrial enterprises. Zaman's company, Zaman & Co., operated six of the seven active pits by 1860.[8] On August 12, 1864, the Porphyry Quarries Company of Quenast (fr|Société Anonyme des Carrières de Porphyre de Quenast) acquired the business and purchased a larger part of the tract.[9] [10]
An experiment was held in 1872 at the Quenast quarry to test lithofracteur and assess its usefulness for the mining industry and military engineering.[7] McKean and Co.'s Rock Drill was operational at the Quenast quarry in 1875.[11]
The porphyry extracted from the quarry at Quenast was frequently used for paving in Berlin, Bordeaux, Cologne, Dunkirk, The Hague, Lille, Paris, and Rotterdam in the 1880s.[12] As of 1887, the quarry in Belgium produced 100,000 paving setts a day.[13] By 1899, the quarries functioned as a cooperative association, allowing workmen to share in a yearly dividend.[14]
Amid World War I in 1914, the Quenast porphyry quarry was abandoned. In 1919, the S.S. Quenast arrived in the River Thames with its first shipment of macadam from the quarry since the outbreak of war.[15]
By 1969, the 400-year-old quarry was supplying stone for the Delta Works, an extensive Dutch flood defence system.[16]