From past to present – Late Pleistocene, last deglaciation and modern glaciers in the centre of northern Fennoscandia INQUA Peribaltic Working Group Meeting and Excursion 2017, 20 – 25 August 2017 Excursion guide and Abstracts Edited by Pertti Sarala and Peter Johansson 1 From past to present – Late Pleistocene, last deglaciation and modern glaciers in the centre of northern Fennoscandia Excursion guide and Abstracts INQUA Peribaltic Working Group Meeting and Excursion 2017 20 – 25 August 2017 Edited by Pertti Sarala and Peter Johansson Geological Survey of Finland Rovaniemi 2017 2 Organized by: Geological Survey of Finland, GTK Oulu Mining School, University of Oulu, OMS University of Stockholm Finnish National Committee of Quaternary Research (INQUA) INQUA Peribaltic Working Group (INQUA TERPRO Commission) Organizing committee: Pertti Sarala and Peter Johansson, Emilia Kosonen (secretary) Recommended reference to this publication: Sarala, P. and Johansson, P. (eds.) 2017. From past to present – Late Pleistocene, last deglaciation and modern glaciers in the centre of northern Fennoscandia. Excursion guide and abstracts of the INQUA Peribaltic Working Group Meeting and Excursion, 20-25 August 2017. Geological Survey of Finland, Rovaniemi, 175 pages. Sponsored by: Geological Survey of Finland Council of Finnish Academies Finnish National Committee of Quaternary Research (INQUA) Layout: Pertti Sarala ISBN 978-952-217-384-3 (pdf) © Geological Survey of Finland This volume is available from: Geological Survey of Finland P.O. Box 96 FIN-02151 ESPOO Electronic version available at: http://www.gtk.fi/ Cover page: Steindalsbreen glacier, photo by P. Sarala. Printed for the excursion in: GTK and KL-Kopio Oy, Rovaniemi 3 Stops Sunday, August 20 (Start at 12 from GTK, Rovaniemi) Stop 1. Peuranpalo - Paleoproterozoic stromatolites V. Perttunen Stop 2. Sihtuuna moraine (minor ribbed moraines) P. Sarala (PS) Stop 3. Liakka (Mid-Weichselian glaciofluvial system) PS Stop 4. Aavasaksa ancient shore line (Deglaciation) P. Johansson (PJ) Sonka (Palojärven Lomakeskus), accommodation, dinner and Get to together party Monday, August 21 Stop 5. Glacially lineated terrain in northern Sweden – drumlins in Kompelusvaara (Middle-Late Weichselian) N. Putkinen (NP) Stop 6. Veiki moraines and Lainio Arc, Junosuando, Sweden (Middle-Late Weichselian) NP, PJ, PS Stop 7. Riipiharju esker and Tärendö interstadial, Sweden (Early-Middle Weichselian) PJ, PS Field lunch Stop 8. Parkajoki – a Neogene landscape with only minor modification by successive Fennoscandian ice sheets A. Hall, K. Ebert, C. Hättestrand Kilpisjärvi (Biological Station and Kilpisjärven retkeilykeskus), accommodation, dinner and sauna 4 Tuesday, August 22 Stop 9. Steindalsbreen Glacier, Lyngen, Norway (trekking whole day) NP, PJ Field Lunch Kilpisjärvi (Biological Station and Kilpisjärven retkeilykeskus), accommodation, dinner and sauna Wednesday, August 23 Seminar and poster session in the Biological Station; lunch and afternoon coffee Business Meeting and Conference dinner Kilpisjärvi (Biological Station and Kilpisjärven retkeilykeskus), accommodation Thursday, August 24 Stop 10. Palsa mires in Iitto, Käsivarsi (short trekking) PJ Stop 11. Deltaic deposit of the Könkämäeno Ice Lake PJ Stop 12. Fell Lapland Visitor Centre in Hetta Stop 13. Hietatievat deflation plane in Enontekiö PJ Field Lunch Stop 14. Pulju moraines (Ice divide zone and deglaciation) PJ, NP Stop 15. Kulkujoki Outwash Channel (Ice Lakes and Deglaciation) PJ Äkäslompolo, Ylläs (Hotel Kuerkievari), accommodation, dinner and sauna Friday, August 25 Stop 16. Hannukainen open pit (Middle Weichselian) Juha Pekka Lunkka (JPL), PS Stop 17. Rautuvaara open pit (Early an Middle Weichselian) JPL, PS Stop 18. Pakasaivo Lake (Deglaciation and melt-water activity) PJ Field Lunch Stop 19. Teuravuoma (Aapa mire, trekking) PJ Drive to Rovaniemi -> at 16:00-17:00 via Airport and Railway station Accommodation Accommodation will be arranged in 2-4 persons’ rooms or apartments in Palojärvi Lomakeskus (www.palojarvenlomakeskus.fi) near Rovaniemi (first night), Kilpisjärvi Biological Station and Kilpisjärven Retkeilykeskus Camping (www.helsinki.fi/kilpis/english/index.htm, www.kilpisjarvi.info/EN/main.html) in Enontekiö, north-western Finnish Lapland (three nights) and Kuerhotel (www.kuerkievari.fi) in Ylläs (last night). The symposium residence will be at Kilpisjärvi Biological Station. 5 Preface The Peribaltic Working Group is an INQUA (International Union for Quaternary Research) research group. It brings together Quaternary and ice age researchers from countries around the Baltic Sea once a year for over twenty years now. The Peribaltic WG is one of the most active working groups and its activities are subordinated to the INQUA Commission on Terrestrial Processes, Deposits and History (TERPRO). The aim of the working group is to enhance the research co-operation between the countries around the Baltic Sea and to create contacts between researchers in different countries. The excursion in 2017 will start on Sunday 20th and end on Friday 25th August in Rovaniemi, Finland. The meeting includes a five-day-excursion to northern Finland, Sweden and Norway, with the theme of ‘From past to present – Late Pleistocene, last deglaciation and modern glaciers in the centre of northern Fennoscandia’. Besides the key stratigraphical points in western Finnish Lapland, the participants will visit different kind of geological localities in northern Fennoscandia, where the glacial dynamics and the circumstances of the glacigenic deposits in the last deglaciation stage are well visible. The field trip will include both the classical localities and new, recently investigated areas as well as one day visit to the modern glacier in Steindalsbreen, Norway. Furthermore, there is one day symposium with paper and poster presentations in the Kilpisjärvi Biological Station at north-western Finnish Lapland. Researchers from eight different countries are gathered together to give lectures, discuss and share the latest research results. At the meeting, 28 lectures are given, 17 of which are oral presentations and 11 flash speeches. In addition, 32 poster presentations are given. This publication contains the revised abstracts of the oral and poster presentations. Prof. Pertti Sarala and Dr. Peter Johansson served as the reviewers and the editors of this publication. This volume is available in the GTK’s web pages as an electronic version at https://gtk.verkkokirjasto.fi/web/arena. The symposium and excursion were organised by the Geological Survey of Finland (GTK) and INQUA Finnish National Commission with the help of the Oulu Mining School at the University of Oulu and University of Stockholm. Special thanks go to Emilia Kosonen, Adrian Hall, Juha Pekka Lunkka and Niko Putkinen. Financial support was given by the Council of Finnish Academies. The editors express our gratitude to all supporting people and organizations. Pertti Sarala and Peter Johansson Rovaniemi 7.8.2017 6 INTRODUCTION Geological background and environments Pertti Sarala and Peter Johansson Finland and northern Fennoscandia are located in the area of the central part of the last Scandinavian Ice Sheet (SIS) of the Weichselian Ice Age (Fig. 1). SIS centre situated in the Scandinavian mountain range and covered Finland and the north-western Russian Plain during several times cold stages of the Quaternary period (e.g. Svendsen et al., 2004; Johansson et al., 2011). It is not known precisely how many times Finland and the northern areas were covered by ice during the Quaternary. This is because the area is situated close to the glaciation centre and the ice advances eroded and deformed most of previously deposited interglacial and glacial sediments during the cold stages (Johansson et al., 2011). Fig. 1. Location of the INQUA Peribaltic Group Meeting and Excursion in 2017 in the centre of SIS (red box). Dashed line shows the zone of last ice divide. Modified after Svendsen et al. (2004). The glaciogenic morphology of Finland varies from subglacial to ice-marginal depositional environments and from active, warm-based ice-lobe network in the south to cold-based, more passive ice in the ice-divide zone in the north (Johansson et al., 2011). Glacial deposits are related to several glacial phases with separate till sheets each associated with glacial striations and till fabrics with varying orientations (Hirvas, 1991; Sarala, 2005). Due to the glaciogenic nature of surficial sediments and their extensive cover (97 % of Finland’s land area) (Johansson & Kujansuu, 2005), surficial geology and morphology form a foundation to nature and all human activities in northern environments. In Finland, and particularly in northern Finland, pre-glacial, weathered bedrock has been largely preserved beneath glacial deposits (Hirvas, 1991; Nenonen, 1995; Hall et al., 2016). The ice divide zone of Central Lapland is the area where the remnants of weathered regolith from some tens of centimetres up to tens of meters thick are frequently found. The thickest weathering profiles are found in topographic depressions under till cover. Typically only the saprock has been preserved, but in places also the lower saprolite (Sarala & Ojala, 2008; Hall et al., 2016), and parts of the upper saprolite are still present displayed as kaolinite deposits. The saprock horizons are strongly fractured and therefore are zones of preferential groundwater movement with enrichment of secondary iron minerals like goethite and some clay minerals (Sarala, 2015). Weathered bedrock has also been served as a ground for glacial erosion and a source for till material which is seen in the composition of the till. 7 Glacigenic sediments are dominant in most of the northern areas (Johansson & Kujansuu, 2005). The Quaternary cover is thickest in depressions and river valleys, thinning out on hill slopes. Till is the most widely spread deposit type and is formed different landform associations in the areas of active ice sheets. Morphologies includes well-formed drumlin and ripped moraine fields but also flat or gently undulating basal till areas and hummocky moraine fields. Sorted sediments relating mainly to the glaciofluvial and glaciolacustric activity and sediment deposition are clearly in minor position, but can form very distinct formation areas in esker and delta valleys. Typical feature in the depression of northern areas is the occurrence of large aapa mire areas which cover underlying sediments and large/long river valleys and lake bodies. In the northernmost fell and mountain areas rocky surface and bedrock outcrops as well as boulder fields are dominant landscape creators. References Hall, A., Sarala, P. & Ebert, K., 2015. Late Cenozoic deep weathering patterns on the Fennoscandi-an shield in northern Finland: a window on ice sheet bed conditions at the onset of Northern Hemi-sphere glaciation. Geomorphology 246, 472-488. Hirvas, H., 1991. Pleistocene stratigraphy of Finnish Lapland. Geological Survey of Finland, Bulletin, 354, 1-123. Johansson, P. & Kujansuu, R. (eds.), Eriksson, B., Grönlund, T., Johansson, P., Kejonen, A., Kujansuu, R., Maunu, M., Mäkinen, K., Saarnisto, M., Virtanen, K. & Väisänen, U., 2005. Pohjois-Suomen maaperä: maaperäkarttojen 1:400 000 selitys. Summary: Quaternary deposits of Northern Finland – Explanation to the maps of Quaternary deposits 1:400 000. Espoo: Geological Survey of Finland. 236 p. Johansson, P., Lunkka, J.P. & Sarala, P., 2011. The glaciation of Finland. In: Quaternary glaciations - extent and chronology : a closer look. Developments in Quaternary Science 15. Amsterdam: Elsevier, 105- 116. Nenonen, K., 1995. Pleistocene stratigraphy and reference sections in southern and western Finland. Geological Survey of Finland, Regional Office for Mid-Finland. Kuopio, 94 p. Sarala, P., 2005. Weichselian stratigraphy, geomorphology and glacial dynamics in southern Finnish Lapland. Bulletin of the Geological Society of Finland 77:2, 71-104. Sarala, P., 2015. Surficial geochemical exploration methods. In: Mayer, W.D., Lahtinen, R. & O’Brien, H. (eds.), Mineral deposits of Finland. Chapter 10.1. Elsevier, Amsterdam. p. 711-731. Sarala, P. & Ojala, V.J., 2008. Implications of complex glacial deposits for till geochemical explora-tion: Examples from the central Fennoscandian ice sheet. In: Stefánsson, Ó. (ed.), Geochemistry Research Advances, Chapter 1. Nova Publishers, New York, pp. 1-29. Svendsen, J., Alexanderson, H., Astakhov, V., Demidov, I., Dowdeswell, J., Funder, S., Gataullin, V., Henriksen, M., Hjort, C., Houmark-Nielsen, M., Hubberten, H., Ingolfsson, O., Jakobsson, M., Kjær, K., Larsen, E., Lokrantz, H., Lunkka, J.-P., Lyså, A., Mangerud, J., Matiouchkov, A., Murray, A., Möller, P., Niessen, F., Nikolskaya, O., Polyak, L., Saarnisto, M., Siegert, C., Siegert, M., Spielhagen, R. and Stein, R., 2004. Late Quaternary ice sheet history of northern Eurasia. Quaternary Science Reviews 23, 1229–1271. Long term geomorphology and weathering in northern Fennoscandia Adrian Hall, Karin Ebert, Clas Hättestrand and Pertti Sarala Four fundamental topographic elements can be recognised in northern Fennoscandia (Fig. 2): the mountain shoulder of the North Atlantic passive margin, the major escarpment that forms the major drainage divide of northern Fennoscandia, with its backslope in northern Finland and Sweden and its foreland on the Kola Peninsula. 8 Fig. 2. Location of northern Fennoscandia. The Norwegian mountain shoulder rises to elevations of >2 km in northern Norway and is developed mainly in the Caledonide nappes. Elevations fall south-eastwards towards the shield plains in northern Sweden. The mountains are deeply dissected but retain fragments of stepped planation surfaces (Lidmar-Bergström et al., 2007). The Saariselkä-Karelia scarp (SKS) reaches 800 m a.s.l. The mainly northward- and eastward- facing SKS is located ~200 km inland of the Barents and White Sea coastlines. The SKS is developed in Precambrian basement and connects in the west via the Saariselkä and other granulite massifs to the northern edge of the Norwegian passive margin in Varanger. In Karelia, the scarp crest drops in elevation southwards and the cuesta form become less distinct and is replaced by the elongate dome of the Maanselkä. The Lapland backslope extends for 300 km from Saariselkä to the Gulf of Bothnia but shortens to <200 km where the scarp turns to the south. The backslope is developed in basement and subsumes several large topographic basins that lie between prominent ridges and hill masses developed on granitic, quarzitic and basaltic gneisses and granulites (Hall et al., 2015). The Barents foreland includes hill masses in Kola that rise in places to elevations equal to or greater than the scarp crest and includes a prominent ridge line that extends from the Saariselkä granulite massif to include the Monchegorsk ultrabasic hills and the Devonian Khibiny and Lovozero alkaline massifs. The foreland also includes major topographic basins, such as the Inari basin, separated by lower hill masses. The eastern Kola Peninsula is formed in Archaean gneisses and shows mainly low relief dominated by an extensive planation surface at 150-200 m a.s.l. These topographic elements are products of episodic Cenozoic uplift and erosion as indicated by analysis of the tectonics of the continental margin (Redfield and Osmundsen, 2013), cooling histories derived from Apatite Fission Track Analysis (Hendriks and Andriessen, 2002; Veselovskiy et al.; Japsen et al., 2016), the sedimentary record of the Norwegian and Barents Sea shelves (Faleide et al., 1993; Musatov and Pogrebitskij, 2000; Petrov et al., 2008; Eidvin et al., 2014) and uplifted planation surfaces (Fjellanger and Sørbel, 2007; Lidmar-Bergström et al., 2007; Lidmar-Bergström and Olvmo, 2015). Eocene and younger marine diatoms found in tills in northern Finland have been interpreted previously as derived from former Palaeogene to Neogene marine sediments in northern Finland (Hirvas and Tynni, 1976; Hirvas, 1991). No in situ 9 sedimentary material has yet been found however and an alternative origin has been proposed with wind transport from eroding sediments of this age exposed on the floor of the Barents Sea during the Early Pleistocene (Hall and Ebert, 2013). Superimposed on these major topographic elements is a series of relief generations, each an extensive assemblage of landforms that developed before and during the Cenozoic in response to prevailing tectonic and climatic regimes and erosional processes (Büdel, 1982). The relief generations exist today in the present landscape of northern Fennoscandia due largely to low Phanerozoic erosion rates (Hall, 2015), including the generally low impact of Pleistocene ice sheet erosion (Ebert et al., 2012) The oldest relief generation is represented by Early Palaeozoic peneplains exhumed from beneath Ediacaran and Cambrian sedimentary cover rocks (Lidmar- Bergström, 1996; Grazhdankin, 2003). Deep erosion occurred during the Late Devonian in Kola but was focussed on the uplifted terrain around the main magmatic centres of Khibiny and Lovozero and decreased into northern Finland (Hall, 2015). By the end of the Triassic relief was low and remained so until the latest Mesozoic (Lidmar-Bergström et al., 2007) but long term cratonic erosion rates of 1-10 m/Myr make it unlikely that any Mesozoic relief elements remain today unless such elements have been exhumed from beneath cover rocks. Younger relief generations developed during regional planation phases in the Palaeogene and Neogene (Ebert et al., 2011; Lidmar- Bergström and Olvmo, 2015). The youngest relief generation is represented by the bedforms of the Fennoscandian ice sheets. Uplift of the Norwegian passive margin commenced in the Late Cretaceous and continued at intervals through the Cenozoic, with an important late uplift phase at ~4 Ma in the Barents Sea (Knies et al., 2014). Humid sub-tropical climates prevailed through the Cretaceous and Palaeogene in northern Fennoscandia. At the Palaeogene–Neogene transition (~23 Ma), cool to warm temperate conditions were established across Fennoscandia and around the Arctic. Cooling at ~10Ma led to the first appearance of sea ice and the establishment of boreal to sub-arctic biomes around the Arctic Ocean (Lavrushin and Alekseev, 2005). By the Early Pliocene (4–5Ma), MATs had fallen to −1°C in the high Arctic (Csank et al., 2011). The onset of glaciation on the Fennoscandian Shield occurred in the Late Pliocene (~2.8Ma) (Flesche Kleiven et al., 2002). Modern MATs are ~1°C in N Finland. Relief generations on the Norwegian mountain shoulder are represented mainly by uplifted and tilted residual hill masses and planation surfaces and former drainage patterns (Fjellanger and Sørbel, 2007; Ebert et al., 2011; Lidmar-Bergström and Olvmo, 2015). On the Lapland backslope in Finland, planation surfaces are represented mainly on the floors of extensive topographic basins separated by large hill masses. In northern Sweden (Fig. 3) extensive inselberg plains are developed on a stepped sequence of planation surfaces. On both the backslope and foreland and within parts of the Saariselkä-Karelia Scarp zone deep weathering mantles are preserved (Kiselev, 1979; Pekkala and Yevzerov, 1990; Islam et al., 2002). Two main types of weathering are recognised: clay-rich kaolinitic saprolite of probably Miocene age (Gilg et al., 2013) or older and sand-rich (grus) saprolite, with vermiculite-dominated clay mineral assemblages of likely Pliocene to Early Pleistocene age (Hall et al., 2015). Weathering mantles extend to depths of many tens of metres in boreholes. In northern Finland the extensive preservation of deep weathering allows the main elements of the Neogene landscape to be reconstructed (Fig. 4), along with the original form of granite inselbergs (Fig. 5).