Oil sands have been mined since the 18th century.[29] In Wietze in lower Saxony, natural asphalt/bitumen has been explored since the 18th century.[30] Both in Pechelbronn as in Wietze, the coal industry dominated the petroleum technologies.[31]
Oil sands have been mined since the 18th century.[29] In Wietze in lower Saxony, natural asphalt/bitumen has been explored since the 18th century.[30] Both in Pechelbronn as in Wietze, the coal industry dominated the petroleum technologies.[31]