The adit of a mine in Finland
One of the last places in the world you would expect gold is Finland, but it does have a very diverse geological history that has led to the creation of many different types of gold deposits of a variety of ages and different styles of mineralization. In the past any gold produced in Finland occurred as a byproduct from the mining of various Volcanogenic Massive Sulfides (VMS). It is only within the past decade that this situation has changed because of the closure of some of the baseball to mines, and the beginning of production from some of the recently discovered gold only deposits. The gold deposits occurred during several distinct episodes of the crustal evolution of Finland. Gold deposits began in Finland during the Archean word forms and greenstone belts with low-grade copper, cobalt and nickel massive sulfides were formed. The same geologic setting created low grade ranging from 0.1 to1.0 ppm of gold but it is in very large deposits. Another type of gold deposit is found in the Tampere schist belt in southern Finland that is host to the Kutemajarvi gold deposits that in the period ranging from 1994 to 2003 produced 13 tons of gold from 1.4 million tons of ore. This mine was reopened in June 2007 by Dragon Mining that now operates under the name of “Orivesi Mine.” The gold deposits in Finland are mainly associated with the Baltic Shield, but in the northern part of the country they are found in the greenstone belts of central Lapland where there are very few deposits having atypical mineralization. Many of these deposits contain a significant enrichment of copper, cobalt, nickel and in some deposits uranium. The areas having the largest potential for gold are to be found in the Paleoproterozoic greenstone belt located in eastern Finland and Lapland. In the western Central Lapland greenstone belt there is the possibility of finding iron oxide, copper and gold deposits. These systems are found in the western part of the Central Lapland greenstone belt. In Central Lapland the greenstone belt is found in the northern part of the Fennoscandian Shield. The mineral deposits found in this area are mainly sulfides and sulfoansenides in nature that also have gold values. In this they resemble BHP Billiton’s deposits at Olympic Dam Mine located in Australia.
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