– home to all geological data

This page is a central location for up-to-date geological documents, and here you can browse, download or buy spatial data products, among others. With interface services, you can use GTK’s datasets free of charge as background data for your services.

The services provided on this website are intended for professionals in geology – if you are not a specialist, you may find services for your needs on our The layman’s sample practice pages.

Hakku search and download service

Hakku is your gateway to all the datasets GTK has published. In Hakku, you can search for and download geological data products dating back all the way to the 19th century. Through the service, you can easily access GTK’s publications, archived reports, maps, photos and spatial data products. Most products can be browsed and downloaded free of charge. You can easily order any products subject to a charge using the Hakku service’s online shop.

Go to the Hakku service

Publications and reports

In the search service, you can find all publications produced by GTK, archived reports compiled by or transferred to GTK, and maps.

Search publications

Spatial data products

Download for free or buy spatial data products in the field of geology. Using the product metadata, you can estimate their applicability to your needs.

Browse spatial data


Browse and download geological photos, free of charge, dating back all the way to the 1870s. You can search for photos by content, location or date.

View photos

Map drawings

Browse GTK’s old geological maps, drawn by hand, and their metadata, ranging from 1850 to 1970. All high-resolution drawings can be downloaded free of charge in JPEG or TIFF format.

Browse maps

Map services

In map services, you can find a large amount of observation and measurement data in visual format. The datasets have been grouped into themes according to their purpose of use, including mineral deposits, bedrock surveying, and peatland surveys. In map services, you can activate the map layers you want, zoom in or out to any scale, and click objects for more information.

Access map services

Ground properties

The ground properties service offers extensive information on Finnish superficial deposits and bedrock. In the same service, you can also access data in the National Land Survey of Finland’s excellent laser scanning service.

Access service


The map application includes Finland’s mineral deposits, mines, mine register data, geological and geophysical maps, and observation and measurement data.

Access MDaE service

Ground investigations

The service for viewing and downloading data on ground investigations, compiled from datasets of several data providers, helps identify the regional ground quality and structure.

Browse data

Acid sulphate soils

Here, you can find information on the locations and properties of acid sulphate soils along Finland’s coastline.

Information on sulphate soils


The Lähde service gives you access to information on bedrock and groundwater surfaces and the thickness of overburden modelled in groundwater areas.

Browse data


The Tapir service shows the natural background concentrations in soil over certain areas. Information on background concentrations is needed in evaluating soil contamination and the need for remediation, for example.

Access Tapir service

Interface services

Interface services offer a technical connection to GTK’s server. Using interface services, you can easily use previously collected data as an addition to or the basis of your database. The use of the services is free of charge, and no registration is required. However, users need to accept the terms of use and understand that, depending on the map layer, access is either restricted, or the right of further use is unlimited.

Access interface services

How to use GTK’s interface services?

You can access GTK’s interface services directly using spatial data software (e.g. QGIS). As a result, you can easily select and retrieve the data you need and use them in your software or download them on your device.

The interfaces are based on open WMS and WFS standards, and they can be used by anyone with access to the technology required. If you need more information on the use of interface services, please contact

Sample archives and collections

Geological surveys and the assessment of raw material resources also include taking a substantial number of physical samples, and some of this material is stored for future use. Measurement and analysis data based on original sampling needs are stored in GTK’s data warehouses. These samples can also be accessed by external parties, including researchers and mining companies, with certain restrictions. Access to the materials requires an existing agreement with GTK. For more information on accessing and using GTK’s research and sample materials, please contact

Access the materials

Drill cores

Solid rock samples extracted from the bedrock with a core drill that have been taken for the purposes of mineral exploration, rock construction and bedrock surveying. Archived drill cores can be studied in the research facilities located in Loppi. Research visits are subject to fees for equipment, labour and accommodation as specified in the price list. Sampling is possible within the scope of the terms and conditions.

More information on archived drill cores

Moraine samples

The samples have been taken from unaltered moraine (horizon C) below the groundwater table at a depth of approximately 1.5–2 metres. They are combined field samples and intended, as a rule, for determining the chemical properties of moraine resources for the needs of mineral exploration and environmental research.

More information on moraine samples

Library services

GTK’s online library and Summon are openly accessible and serve everyone interested in geosciences. Registered users can also borrow materials. To register, visit GTK’s library in person or create your user account online.

Access the online library

Online library

The GTK library is a public library that serves everyone requiring geological information. Our library is home to the largest geosciences collections in Finland. The online library gives you access to information on the library’s services, borrowing instructions, available databases, online sources, glossaries and contact information. You can also make searches and reservations, renew your loans, place data service requests, and ask for instructions.

Access the online library.


In Summon, you can find all literary material available in our library, including the e-journals to which we have subscribed, their full-text articles, e-books, and all other material available in our library system. Currently, there are more than 50 million records. Any e-journals or e-books carrying a charge can only be accessed using devices connected to GTK’s network. However, the search, availability and reference information, abstracts, a light altmetrics view, and open access publications are available to everyone, and you can also expand your search to material outside our library collections.

Access Summon.

Terms of use of products and services

Datasets and spatial data products are largely owned by GTK, and their use is subject to certain conditions and practices. The PDF files below indicate how and where you can use GTK’s datasets.



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    Tomi Rönkkö
    Head of Unit, Information Solutions
    +358 29 503 3279