Finland
In 2007, Greg attended an international Spatial Data Modelling seminar in
Rovaniemi, Finland. He presented
several talks on the applications of modelling in the mineral exploration
and environmental fields (see
http://projects.gtk.fi/SDM/index.html). Subsequent discussions with
staff from the Finnish Geological Survey indicated Finland had significant
potential for new discoveries as, in their view, many commodities remained
highly unexplored. Additionally, Finland has excellent geological
databases, good infrastructure and readily available exploration services.
As a result of this sequence of events, Kenex
compiled a GIS of
available relevant historical exploration data over the Central Lapland
Greenstone Belt
late in 2008.
We used this GIS to undertake predictive modelling that identified
targets for orogenic gold exploration.
Orogenic gold is the most common style of gold
mineralisation in Finland with ~140 known occurrences.
It has been described in all tectonic districts, in both Archean and
Proterozoic domains, but is particularly well known in greenstone belts in
Central Lapland.
This region is dominated by Archean and
Palaeoproterozoic metamorphosed mafic to ultramafic volcanics with lesser
volumes of coeval meta-sedimentary rocks and slightly younger felsic to
intermediate intrusives. It is structurally complex with numerous crustal
scale reverse, normal and detachment faults, often intersecting each other.
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Map showing distribution of faulting in the area. Training data represented by white circles |
Map showing metamorphic lithologies in the project area. Training data represented by white circles. |
Although the Central Lapland Greenstone Belt is one
the richest gold producing regions in Finland and contains numerous orogenic
gold, iron oxide copper gold and palaeoplacer gold deposits, there are also
a number of deposits with an atypical metal association including
significant copper, cobalt, nickel and/or uranium. These elements are
typically present in minor to sub-economic concentrations, although copper
has been extracted from Saattopora and Sirkka. It has been suggested this
unusual metal association is the result of orogenic evolution in an area
where pre-existing intracratonic basins containing extensive evaporite
sequences have produced anomalously saline ore fluids, and in turn,
transport of base metals.
Kenex’s final Finland prospectivity model will be used to assess
mineral exploration tenders, provided by the Finish Ministry of Trade and
Industry, and has provided a valuable mineral exploration tool for clients
looking for prospective areas not yet covered by mineral exploration
tenements.
Prospectivity model by staff from Finland Geological Survey for IOCG mineralisation
For more about projects in Finland contact Greg here at Kenex.