Geologists are the mine’s detectives

December 13, 2018
Ariam Pradenas, Maurice Pawlik, Angelica Ärlebrand, Ben Pladdy, Zacharias Enholm, Joakim Johansson och Barbro Andersson, all geologists at LKAB.

The rate of exploration in Malmberget has increased in recent years."The challenges we face now are greater than before. The deeper we go, the more information we must get about mineralisation and barren rock," says Monika Sammelin, acting exploration department manager at LKAB.

Exploration is time-consuming work that begins with a review of the existing information, continues with field studies and surveys before moving to test drilling and building models of the local area.”Because every metre we drill costs around SEK 1,000, and this does not include buildings the test drift or subsequent analyses, we have to find out as much as possible before we begin drilling,” she tells us.

These 300 to 700-meter holes are drilled according to a fixed pattern that gradually grows denser. Kilometre after kilometre of drill cores are charted and analysed in the Gällivare charting hall before being sent away for chemical analysis. All of the data collected is pieced together in a geological model in order to draw conclusions about how the ore bodies and barren rock look. The models are refined as soon as new information is received.

Malmberget has a challenging geology and a large number of ore bodies. The area has been affected in various ways since the ore was formed around 1.9 billion years ago. The rock contains both folds and metamorphoses created by hot fluids and pressure resulting from movement in the rock. “Geologists are like detectives who are always looking for clues. We have a theory about what has happened in the area and all the information we gather helps us draw conclusions. We’ve seen a number of interesting anomalies – differences in values – from geophysical surveys that we cannot explain but must investigate moving forward,” says Monika Sammelin.

Before we can even begin to drill we need underground roads, and this year we began construction of a test drift for the Fabian ore body. Also, next year we’re planning to build so-called ramps (roads) down from the current main level at a depth of 1,250 metres to enable future investigations on new levels.”

It still too early for us to say how things look at deeper levels, but it’s in our major Printzsköld, Alliansen and Fabian ore bodies that we must secure future volumes. Ore is not just something you stumble across; finding it is hard work and it must be economical to extract the mineralisations we find before we can begin to call it ore,” says Monika Sammelin.