National Drill Core Archive

Bedrock drilling from exploration, mining activities and rock construction produces drill cores. GTK receives representative drill cores according to Mining Act (621/2011), and archives them systematically. Over the decades, more than 3.6 million metres of drill cores have accumulated in the archive.

GTK’s national drill core archive is based in Loppi. In addition, GTK has a storage facility in Rovaniemi to serve the customers in Northern Finland. Loppi, Rovaniemi and Kuopio have facilities for study of the drill cores. The facilities are equipped with appropriate research equipment.

Drilling information from map service

Information on the drilling sites and their locations, from which the drill cores in the drill core archive have been collected, can be found on the Mineral Deposits and Exploration map.

At the map service it is possible to simultaneously study several data layers, useful for exploration, originating from GTK and other data sources. Most of these information products originating from GTK, are down-loadable free of charge at the Hakku service. Down-loadable free products contains usually only basic information. In the case of additional, chargeable data (measurements, loggings and assays), please contact:

The archive’s visitor services and research activities

Drill cores can be studied in these facilities with the help of GTK’s experts if required. See available dates and sites in the calendar.

Visits are subject to fees for use of equipment, labour and accommodation, according to the price list.

Sampling and cutting

Sampling is possible according to the terms and conditions, also a valid agreement is required. Sampling is not allowed for studies requiring large amount of sample material, e.g. metallurgical concentration tests. The purpose of the sampling will be checked and approved before signing of the contract and checked at every booking.

Drill core samples are cut with a diamond disc. All the facilities have two manual and one automatic core cutting saw with diamond disc. The saws are equipped with a cutting deck and a sample holder. The maximum cutting length of the sample is 0,5 meters. The saws can be equipped with a 35 cm diameter disc that allows cutting drill cores up to 10 cm thick.


Before the drill cores are cut, they can be photographed. The cores can be either wet or dry during photographing. The camera is installed above the drill core tables so that the samples are photographed perpendicularly to the core box. Two boxes fit in one photograph. The photographs are given as high-resolution JPG or TIFF files.

Density measurements

Computer controlled density measurements can be carried out at the Loppi and Rovaniemi facilities. The measurements are taken by first measuring the sample’s specific gravity in reference to air. After that, the sample is measured in reference to water. The difference between the measurements is used to calculate the sample’s volume. The sample’s specific gravity is calculated based on the results of the measurements in reference to air and water. The calculator will also account for the corrections required by the temperatures of the air and water used in the measuring.

Measurements related to a sample’s magnetisation

The sample’s magnetic susceptibility can be measured with a handheld device at Loppi. At Rovaniemi facility the susceptibility measurements can also be carried out with an alternating current bridge (1024 Hz). At Rovaniemi also remanent magnetisation can be measured with a fluxgate magnetometer inside magnetic shielding. The measuring devices are computer-controlled and do not damage the sample.


A sample field analyser (pXRF) is available for hire at the drill core archive.

Rents and prices per person for the drill core archive’s research facilities

List of service charges

Terms and conditions for delivering and handing over drill cores to the archive

The drill core archive receives all representative sets of exploration drill cores in accordance with the Mining Act (621/2011), following the approval of the archive proposal by the mining authority (TUKES).
Terms and conditions

GTK, Loppi Drill Core Archive
Mustinsuontie 159
GTK, Rovaniemi Drill Core Storage
Lepikontie 9B
GTK, Kuopio
Neulaniementie 5
Tel. +358 029 503 2672 / Jani Riikonen Tel. +358 29 503 0026 / Sulevi Juupaluoma Tel. +358 29 503 0100 / Toni Kolari
Contact the drill core archive
Open: Mon – Thu 8-16, Fri 8-14 Open: Mon – Thu 8-16, Fri 8-14 Open: Mon – Thu 8-16, Fri 8-14