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Division of Biogeoscience
Division of Geology and Geochemistry
Division of Urban Geograpahy and Regional Studies
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P.O. Box 64
(Gustaf Hällströmin katu 2a)
FI-00014 University of Helsinki

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(Gustaf Hällströmin katu 2b)
FI-00014 University of Helsinki

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Yrjö Kähkönen, Ph.D.

Kähkönen

University Lector in Geology and Mineralogy, retired 2010

Department of Geosciences and Geography
P.O.Box 64 [Gustaf Hällströmin katu 2a]
FIN-00014 UNIVERSITY OF HELSINKI

tel: +358-9-191 50811
cel: +358-40-526 0636
eMail:  yrjo.kahkonen@helsinki.fi

Education

  • Docent of Petrology, University of Helsinki, 1992
  • Ph.D., Department of Geology, University of Helsinki, 1989
  • M.Sc., Department of Geology, University of Helsinki, 1973?
  • B.Sc., Department of Geology, University of Helsinki, 1969?

Teaching Topics

  • The Finnish bedrock
  • Structural Geology
  • Petrology
  • Field Geology

Research Topics

  • Origin and evolution Proterozoic supracrustal rocks
  • Paleovolcanology
  • Geochemistry
  • Evolution of the continental crust

Selected Recent Publications

Papers

Kähkönen, Y., 1994: Shoshonitic and high-K metavolcanic rocks in the southern parts of the Paleoproterozoic Tampere Schist Belt, southern Finland: evidence for an evolved arc-type setting.
–Geological Survey of Finland, Spec. Pap. 19, 101-115

Kähkönen, Y., 1998: Svekofenniset liuskealueet – merestä peruskallioksi. 199-227
in M. Lehtinen, P. Nurmi & T. Rämö (eds.), 2003: Suomen kallioperä – 3000 vuosimiljoonaa.
–Suomen Geologinen Seura

Kähkönen, Y., 1999: Stratigraphy of the central parts of the Palaeoproterozoic Tampere Schist Belt, southern Finland; review and revision.
–Bulletin of the Geological Society of Finland: 71, 13-29

Kähkönen, Y., in press: Svecofennian supracrustal rocks. 343-406
in M. Lehtinen, P. Nurmi & T. Rämö (eds.), in press: Precambrian Bedrock of Finland – Key to the Evolution of the Fennoscandian Shield.
–Elsevier, Amsterdam

Kähkönen, Y. & Leveinen, J., 1994: Geochemistry of metasedimentary rocks of the Paleoproterozoic Tampere Schist Belt, southern Finland.
–Geological Survey of Finland, Special Papers 19, 117-136

Kähkönen, Y. & Nironen, M., 1994: Supracrustal rocks around the Paleoproterozoic Haveri Au-Cu-deposit, southern Finland: evolution from a spreading center to a volcanic arc environment.
–Geological Survey of Finland, Special Papers 19, 141-159

Kähkönen, Y. & Lehtinen, M., 1998: Geologian peruskäsitteitä. 23-91
in M. Lehtinen, P. Nurmi & T. Rämö (eds.), 1998: Suomen kallioperä – 3000 vuosimiljoonaa.
–Suomen Geologinen Seura

Tiainen, M. & Kähkönen, Y., 1994: Geochemistry of the Paleoproterozoic andesitic to rhyolitic arc-type metavolcanic rocks of Haukkamaa, Kuru, central Finland.
–Geological Survey of Finland, Special Papers 19, 29-44

Vaarma, M. & Kähkönen, Y., 1994. Geochemistry of the Paleoproterozoic metavolcanic rocks at Evijärvi, western Finland.
–Geological Survey of Finland, Special Papers 19, 47-59

Edited Volumes

Nironen, M. & Kähkönen, Y., (eds.), 1994: Geochemistry of Proterozoic supracrustal rocks in Finland.
IGCP Project 179 Stratigraphic Methods as Applied to the Proterozoic Record and IGCP Project 217 Proterozoic Geochemistry.
–Geological Survey of Finland, Special Paper 19, 184 pp

Kähkönen, Y. & Lindqvist, K., (eds.), 1999: Studies Related to the Global Geoscience Transects / SVEKA Project in Finland.
–Bulletin of the Geological Society of Finland 71, Part 1, pp. 1-218

Haapala, I. & Kähkönen, Y. (eds.), 2002: Proceedings of IGCP 373 Project Field Conference on Rapakivi Granites and Associated Mineralization. Finland, 3-7 July, 2000.
–Bulletin of the Geological Society of Finland 74, Parts 1-2, 7-157

Courses in 2005-2006

  • The Finnish bedrock
  • Elements of structural geology
  • Geology in the field: mapping Precambrian bedrock
  • Thin section exercises in petrology courses
  • Advanced bedrock mapping

Graduate Students

  • Pasi Heino (Geology and geochemistry of Paleoproterozoic metavolcanic rocks and till geochemistry at Latovainio, Forssa, southern Finland)
  • Jussi Heinonen (Geology and geochemistry of Paleoproterozoic metavolcanic rocks at Takamaa, Ylöjärvi, southern Finland)

Research Statement

KähkönenSince the 1970’s, my research has mainly focused on Paleoproterozoic supracrustal of central and southern Finland. My Ph.D. thesis dealt with the geochemistry, petrology and stratigraphy of the ca. 1.9 Ga metavolcanic rocks of the Tampere supracrustal (greenstone) belt. In spite of compositional changes after deposition, a volcanic arc setting for the bulk of these rocks and a division of the belt into chemo-stratigraphic units could be suggested. At the postdoctoral stage, I have continued (as a teaching assistant of the Department of Geology, University of Helsinki) research on Finnish Paleoproterozoic supracrustal belts. During the latest ten years I have broadened my research agenda to include, in addition to geochemistry, petrology and stratigraphy, aspects of physical volcanology, i.e., volcanic processes, products and successions of the Tampere belt.

My Ph.D. thesis was fundamentally sponsored by Outokumpu Co. Much of my post-doctoral studies have been done as active collaboration with Geological Survey of Finland (GSF). In particular, the role of the Isotope Laboratory of the GSF and the activities within the Global Geoscience Transects –project, led by. Prof. Kalevi Korsman of the GSF, have been important. The U-Pb age determinations done in collaboration of the Isotope Laboratory have resulted in a considerably detailed concept of the evolution of the Tampere belt succession. The support from the Academy of Finland within the IGCP Project 217 was also most significant.

During the years gone I have participated several International Geological Correlation Programme of UNESCO and IUGS. These include IGCP Projects 161, 179, 217, 275, 371, and the currently active IGCP-502. I acted as the coordinator and chair of the National Working Group of IGCP Project 217 Proterozoic Geochemistry.

Research Projects

  • Paleoproterozoic metavolcanic and metasedimentary rocks around Palvajärvi, Tampere Schist Belt, southern Finland
  • Stratigraphy and paleovolcanology of the Tampere belt
  • TIMS and SIMS ages on metavolcanic rocks from the Paleoproterozoic Tampere belt, southern Finland (in cooperation with Hannu Huhma and Irmeli Mänttäri, GSF)
  • Paleoproterozoic metavolcanic and metasedimentary rocks at Suodenniemi, Tampere Schist Belt, southern Finland (in cooperation with Mikko Nironen, GSF)
  • Geology and geochemistry of Paleoproterozoic supracrustal rocks around at Kalkku and Tesoma, Tampere Belt, southern Finland
  • Paleoproterozoic metavolcanic rocks at Vihteljärvi, Kankaanpää, Tampere Schist Belt, southern Finland
  • Geochemistry of Paleoproterozoic metavolcanic rocks at Kuustenlatva, Hämeenkyrö, southern Finland
  • Geology and geochemistry of Paleoproterozoic amphibolites at Kiikoinen, southern Finland
  • Metaconglomerates and related rocks at Rämsöö, Vesilahti, Paleoproterozoic Vammala Migmatite Belt, southern Finland (in cooperation with Hannu Huhma and Irmeli Mänttäri, GSF)
  • MORB-like Paleoproterozoic mafic metavolcanic rocks at Urjala, southern Finland (in cooperation with Markku Tiainen, GSF)
  • The Paleoproterozoic Välimäki conglomerate, Lavia, southern Finland