Erzberg Mountain (upper Styria, in the Eisenerz Alps), alt. 1,466 m, also called "Steirische Pyramide" (Styrian pyramid); the largest open-cast ore mining site in Central Europe and the largest deposit of siderite (FeCO<sub>3</sub>) in the world. Because of the aggregation of siderite with low-iron ankerite the iron content ranges between 22 % and 40 %. From a geological point of view the mountain Erzberg is part of the greywacke zone, which contains limestone and slaty rocks from the Palaeozoic period and extends from Lower Austria to Tirol. There is evidence of ore mining at the Erzberg dating back to the Romans ("iron from Noricum", approximately 4th century A.D.), and further evidence of ore mining from the year 712, the first documented mention dating from the year 1171. A show-mine was established in parts of the deep mine, which was shut down in 1986, there are 30 "adventure stations" in 4 km of tunnels on 2 levels. In the 19th century, under Archduke Johann the Erzberg gained in importance. In 2000 the deposit content amounted to approximately 140 million tons of utilisable siderite. In 2000 mining activity, which was carried out by VOEST-ALPINE Erzberg Ges.m.b.H., took place in an open cast mine with 25 stories, each having a height of 24 m. 1.3 million tons of ore per year is mined, with an average iron content of 33,6 %; first the ore is separated from barren rocks and then transported by railway to Linz and Donawitz for smelting ( VOEST-ALPINE STAHL AG).
Literature#G. Sperl, Montangeschichte des Erzberggebietes nach archaeologischen und schriftlichen Dokumenten, 1988.