Viking weapons, BBC-Viking raiders
Why vikings?
I must admit that I’ve always been fascinated about vikings. Their freedom, versatility and enthusiasm in combat were always on the back of my brain, but also their practically and intricate designed axes and blades.
I also have to admit that until very recently I had no idea how smart these people were actually in mining the ore that produced them. Well, not quite classical mining, more harvesting… You see, even though Scandinavia has plenty of mineral resources, including iron, the local populations were mining it only in small percent, probably due to the long distances and harsh weather conditions, so they turned to an easier source-bog iron.
So what is this about in real life?
In high latitudes areas such as the Scandinavian Peninsula, there are countless swamps and lakes formed due to the high quantity of precipitations, low temperatures and lack of evaporation. Most of them are formed in flat areas covered by glacial deposits and low in nutrients. Due to this lack of nutrients, the only vegetation that colonize them are plants such as Sphagnum (if the waters are more acidic), or various reeds and sedges (if the waters are more alkaline). In wet and cold environments, the dead plants decompose at slow rates due to the lack of oxygen in the water and build up layer upon layer feeding the bogs, which grow larger and larger over thousands of years. Thus, these bogs work as sediments traps and chemical exchange environments.
Wetlands in Denmark (pinterest.co.uk)
Scandinavia has not only a fascinating history, but also geology. Denmark, Sweden and Norway (the modern names of territories occupied by vikings) lay on the top of the Baltic shield which bears some of the oldest rocks in the world (~3 billion years).
Cool, right? The peninsula also has a mountain range (the Scandinavian orogeny) which formed by the closure of an ancient ocean called Iapetus, somewhere approximately 500 million years ago. Thus the rocks that cover the area are mostly of magmatic and metamorphic origins and rich in various minerals. Pluvial and glacial agents facilitated in time the erosion, transport and accumulation of some of these minerals in areas with lower altitudes (our bogs or beaches).
Another way to get out minerals of these rocks is with the help of tectonics. Water is circulating in time through fractures and fissures of rocks, washes them and gets enriched in various chemical elements. When this water reaches the surface (commonly as springs), the chemical compounds transported in solution precipitate and form new minerals. When underground or infiltration water washes rocks rich in iron, it will dissolve it. The ores resulted from this chemical process are oxihydroxides (mainly goethite) but also oxides like magnetite or hematite.
Iron-bearing water (wallykid.com)
The new formed crystals are aggregating and form shapes of various dimensions. They can be from few mm up to tens of cm in diameter. These aggregates (nodules) were gathered by people, dried then smelted in whatever was needed. The quality of the obtained steel wasn’t the best but it was used on large scale for various products such as weapons, cutlery, boats metal elements and even garments. Sometimes the quality was raised by adding normal iron ore or melted existing objects. Legend has it that vikings were incorporating bones of humans or animals in the melting process in order to give the weapons magical power…
Of course that iron wasn’t the only mineral exploited by vikings, the geological market including also copper, zinc, silver and gold. More, the better…The ‘harvesting’ of bog iron was used not only in Scandinavia, but also in Iceland and then modern day Russia, in the new conquered territories and later in North America. The method was used since earlier times but never at such scale as in the Viking era. The constant need of metal and new emerged technologies made the exploitation succesful and popular throughout the entire Northern Europe.
Taking this in consideration, I am going to prospect for some ore deposits. :))
If I would have lived in those times, for sure I would have been a warrior… A shield maiden. :P
If you want to see how it’s done, check the confession of an archaeologist on his bog iron-quest: