Geological Survey of Finland 2021 Developments in map data management and geological unit nomenclature in Finland Jarmo Kohonen and Timo Tarvainen (eds) Bulletin 412 • Special Issue Geological Survey of Finland • Bulletin 412 • Special Issue Geological Survey Finland • Bulletin of Jarmo Kohonen and Timo Tarvainen (eds) and Timo Tarvainen Jarmo Kohonen Geological Survey of Finland, Bulletin The Bulletin of the Geological Survey of Finland publishes the results of scientific research that is thematically or geographically connected to Finnish or Fennoscandian geology, or otherwise related to research and innovation at GTK. Articles by researchers outside GTK are also welcome. All manuscripts are peer reviewed. Editorial Board Dr Saku Vuori, GTK, Chair Dr Stefan Bergman, SGU Dr Asko Käpyaho, GTK Dr Antti Ojala, GTK Dr Timo Tarvainen, GTK, Scientific Editor Instructions for authors available from the Scientific Editor. GEOLOGICAL SURVEY OF FINLAND Bulletin 412 Developments in map data management and geological unit nomenclature in Finland by Jarmo Kohonen and Timo Tarvainen (eds) Unless otherwise indicated, the figures have been prepared by the authors of the article. https://doi.org/10.30440/bt412 Received 15.9.2020; Accepted in revised form 13.4.2021 Layout: Elvi Turtiainen Oy Espoo 2021 Kohonen, J. & Tarvainen, T. (eds) 2021. Developments in map data management and geological unit nomenclature in Finland. Geological Survey of Finland, Bulletin 412, 169 pages, 41 figures, 18 tables and 4 appendices. The ongoing transition from maps to 3D modelling of geology needs to be supported by efficient infrastructure, both within the Geological Survey of Finland (GTK) and nationally. One key com- ponent is the easy use of geological map data in forward modelling processes. In practice, this means consistency, standardization and traceability of all the interpreted map data. The first paper (Ahtonen et al.) describes the structure of the new GTK Map Data Architecture (MDA) within the broader context of National Geological Framework of Finland (NGFF). MDA will be founded on three pillars: (1) structured spatial data, with the map objects and related attri- butes arranged as thematic layers; (2) structured non-spatial data (Finstrati databases for defined geological units; Finstruct database for major bedrock structures) and (3) linked documentation, including key references to the original geological descriptions and scientific content. The MDA is designed to meet the needs of various use cases and to enable access to all kinds of geological information. The Precambrian crystalline bedrock of the Fennoscandian shield area is covered by a thin layer of superficial deposits of Quaternary age. The distinctly twofold characteristics of Fennoscandian geology are directly reflected in the mapping concepts and in the research tradition in Finland. The last three contributions of the volume consider the principles of geological map unit division. The second paper, “Terminology and division of tectonic-scale map units in Finland” (Kohonen et al.), clarifies the connection between the prevailing tectonic evolution models and the national bedrock map compilations. The new, coherent classification system for tectonic-scale map units consists of three categories: crustal province, tectonic province and structural province. The ca- tegories are conceptually independent, which allows both the subdivision and spatial overlapping of the map units. Key attributes for characterization of all the province categories are provided. The third paper (Luukas & Kohonen) summarizes the current ideas concerning thrust tectonics in Finland. The new province division presented in the second paper has been utilized here in the arrangement of the thrust systems. The authors present a country-wide compilation of the major thrust-bounded units in Finland. All the units (nappes, allochthons and thrust stacks) are named, characterized and linked to the corresponding detachment. The Quaternary superficial deposits were deposited on the bedrock mainly during and after the last glaciation as a result various glacial and postglacial processes. The fourth paper (Palmu et al.) presents a comprehensive and coherent system for the management of the superficial map units in Finland. The approach is based on four parallel systems: (1) glacial dynamic (GD) classification (provinces and regions), (2) morpho-lithogenetic (MLG) classification, (3) lithostratigraphic clas- sification, and (4) allostratigraphic classification. The refined GD approach creates an overall map unit framework, whereas MLG classification is applied to interpretations of glacial landforms from high-resolution (2m grid) LiDAR DEM data. Lithostratigraphy and allostratigraphy are standard methods in type section based mapping and in marine geological surveys, respectively. Keywords: Geological map data, map data architecture, classification system, map unit, Precam- brian, Quaternary, Finland Jarmo Kohonen Geological Survey of Finland P.O. Box 96 FI-02151 Espoo Finland E-mail: [email protected] Timo Tarvainen Geological Survey of Finland P.O. Box 96 FI-02151 Espoo Finland E-mail: [email protected] ISBN 978-952-217-410-9 (pdf) ISSN 0367-522X (print), ISSN 2489-639X (online) 2 CONTENTS Editors’ preface .................................................................................................................................................. 4 Jarmo Kohonen and Timo Tarvainen GTK Map Data Architecture: the core of the developing National Geological Framework of Finland ........7 Niina Ahtonen, Jarmo Kohonen, Jouni Luukas, Antti E. K. Ojala, Jukka-Pekka Palmu and Jouni Vuollo Classification of regional-scale tectonic map units in Finland .....................................................................33 Jarmo Kohonen, Raimo Lahtinen, Jouni Luukas and Mikko Nironen Major thrusts and thrust-bounded geological units in Finland: a tectonostratigraphic approach .........81 Jouni Luukas and Jarmo Kohonen Classification system for Superficial (Quaternary) Geological Units in Finland ....................................... 115 Jukka-Pekka Palmu, Antti E. K. Ojala, Joonas Virtasalo, Niko Putkinen, Jarmo Kohonen and Pertti Sarala 3 Developments in map data management and geological unit nomenclature in Finland Edited by Jarmo Kohonen and Timo Tarvainen Geological Survey of Finland, Bulletin 412, 4–6, 2021 EDITORS’ PREFACE All the contributions to this volume consider the management of geological map data. The main focus is on questions related to data architectures and underlying geological classification systems, not on information system technologies. All the examples represent activities by the Geological Survey of Finland (GTK), but the underpinning concepts are generic and basically applicable any- where with a similar geological environment. The geological map – an anachronism? Since the early 19th century, printed geological maps have formed the fundamental foundation in the representation of geological relationships in regional geology. A geological map is essentially a 2D model, an interpretation based on the compiler’s ideas of the geology, often supported by cross-sections, structural drawings and stratigraphic diagrams. The traditional geological mapping has been under pressure: the relevance of the printed format was undermined by GIS technologies and online data delivery, while the 2D-model concept has been eroded by technologically advanced modelling technologies, and long-term mapping programmes are challenged by cost-efficient thematic and targeted field strategies. However, the fundamental drawback of the traditional map format and related mapping procedure may be none of these, but the conceptual limitations and, especially, the narrow data model speci- fications. Geology consists of several subtopics, such as petrology, structural geology, stratigraphy and metamorphic geology, and all these utilize the spatial representation of data and interpre- tations. Any map with a scale, layout and legend has resolution limitations, both in the amount of detail and overlapping map features. The cornerstone of the shifted paradigm is no longer a printed one-layout map series but efficient storage of accessible versatile map information – the system. A modern map data architecture allows different approaches (e.g. tectonic, stratigraphic, structural) via a theme-layer-based structure. As a result, the geological features can be stored in all the richness provided by the alternative approaches. The combined use of the map themes enables a complete view of all aspects of the up-to-date regional geology. The role of a modern Geological Survey The transition from 2D to 3D modelling of geology needs to be supported, both within the Geological Survey of Finland (GTK) and nationally, by an efficient infrastructure. In the future, one key function of GTK will be to provide reliable geological spatial data and interpretation for various application areas, such as mineral potential assessment and infrastructure planning. In any for- ward modelling process, the consistency, standardization and traceability of the input map data are of crucial importance. In practice, the transformation from map sheets to data architectures is a tedious process. The planning and maintenance of the system is not possible without a truly systemic approach with common rules, defined terms and harmonization of the legacy information – including maps with variable classification systems. Positively, generic conceptual models, such