DOI article:
Deicke, Matthias: Findings concerning the environmental history of the Harz Mountains and the utilisation of mineral resources
DOI Page / Citation link:https://doi.org/10.11588/diglit.56859#0094
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Early mining in the Upper Harz was restricted to depths of about 20 m.
Inrushing groundwater prevented penetration to greater depths. This forced the
miners to extend their pits laterally. The consequence of this was, as the records
show, that all ore dykes of the Harz have been mined already since medieval
times. Mining reached deposits at greater depth only after drainage tunnels and
pumps had been put in place in more recent times.
The dyke ores of the Upper Harz consist mainly of galena and sphalerite with
low chalcopyrite content (Fig. 5). The formation of single-mineral ores in so
called „nests“ made it possible to separate the different minerals and the dead
rock. This had not been possible with ores from Rammelsberg. Only lead ore was
used during medieval times, principally to extract its silver content, not the lead
itself. 100 % galena contains up to 1 % silver.
Iron ores
The red iron ores of the Harz are tied to the Mid-Devonian basaltic volcanism
and are therefore localised along the diabase range of the Upper Harz. The
deposits formed as co-precipitates with SiO2 when acidic, ferric (FeCl3) solutions
came in contact with oxidising seawater. These red iron ores contain about 35-
60 % iron. They were difficult to mine and smelt due to their high SiO2 content.
The iron ores from the Upper-Devonian limestone reefs of the Iberg/ Winter-
berg complex were deposited in fracture zones as siderite (FeCO3) by metaso-
matic transformation of carbonates in contact with iron carrying solutions. In
many cases further exposure of the siderite ore to groundwater caused alteration
into limonitic ores (FeOOH). This product of weathering was easily mined and
refined. The iron ores of Iberg have presumably been mined since the first
century AD. The smelting of iron ores and the production of iron tools was a
prerequisite for the mining of non-ferrous metals.
All of the types of ore described thus far have been identified in the archaeo-
logical excavation at Düna as early as the third century AD. Since very little is
known about the extent to which the coppershales of the southern Harz foreland
have been mined we will not discuss them here.
The smelting of the above mentioned iron ores had, apart from the high
energy demand, little impact on the environment. In contrast to this the smelting
of the dyke ores from the Upper Harz caused substantial emissions of fine
particulate and gaseous pollutants which will be discussed in the following.
Prior to smelting the dyke, ores of the Upper Harz were dressed to remove
dead rock and valueless minerals. This was done by sorting the ores manually and
Early mining in the Upper Harz was restricted to depths of about 20 m.
Inrushing groundwater prevented penetration to greater depths. This forced the
miners to extend their pits laterally. The consequence of this was, as the records
show, that all ore dykes of the Harz have been mined already since medieval
times. Mining reached deposits at greater depth only after drainage tunnels and
pumps had been put in place in more recent times.
The dyke ores of the Upper Harz consist mainly of galena and sphalerite with
low chalcopyrite content (Fig. 5). The formation of single-mineral ores in so
called „nests“ made it possible to separate the different minerals and the dead
rock. This had not been possible with ores from Rammelsberg. Only lead ore was
used during medieval times, principally to extract its silver content, not the lead
itself. 100 % galena contains up to 1 % silver.
Iron ores
The red iron ores of the Harz are tied to the Mid-Devonian basaltic volcanism
and are therefore localised along the diabase range of the Upper Harz. The
deposits formed as co-precipitates with SiO2 when acidic, ferric (FeCl3) solutions
came in contact with oxidising seawater. These red iron ores contain about 35-
60 % iron. They were difficult to mine and smelt due to their high SiO2 content.
The iron ores from the Upper-Devonian limestone reefs of the Iberg/ Winter-
berg complex were deposited in fracture zones as siderite (FeCO3) by metaso-
matic transformation of carbonates in contact with iron carrying solutions. In
many cases further exposure of the siderite ore to groundwater caused alteration
into limonitic ores (FeOOH). This product of weathering was easily mined and
refined. The iron ores of Iberg have presumably been mined since the first
century AD. The smelting of iron ores and the production of iron tools was a
prerequisite for the mining of non-ferrous metals.
All of the types of ore described thus far have been identified in the archaeo-
logical excavation at Düna as early as the third century AD. Since very little is
known about the extent to which the coppershales of the southern Harz foreland
have been mined we will not discuss them here.
The smelting of the above mentioned iron ores had, apart from the high
energy demand, little impact on the environment. In contrast to this the smelting
of the dyke ores from the Upper Harz caused substantial emissions of fine
particulate and gaseous pollutants which will be discussed in the following.
Prior to smelting the dyke, ores of the Upper Harz were dressed to remove
dead rock and valueless minerals. This was done by sorting the ores manually and