U-Pb zircon, monazite and xenotime geochronology of cordierite-anthophyllite and felsic volcanic rocks in Orijärvi, southern Finland
: Teemu Vehkamäki, Markku Väisänen, Yann Lahaye, Matti Kurhila, Bo Johanson
: Ilmo Kukkonen, Suvi Heinonen, Hanna Silvennoinen, Fredrik Karell, Elena Kozlovskaya, Arto Luttinen, Kaisa
Nikkilä, Vesa Nykänen, Markku Poutanen, Pietari Skyttä, Eija Tanskanen, Timo Tiira, Kati Oinonen
: SYMPOSIUM ON STRUCTURE, COMPOSITION AND EVOLUTION OF THE LITHOSPHERE
Publisher: Institute of Seismology, University of Helsinki
: Helsinki
: 2018
: LITHOSPHERE 2018
: Report S
: 67
: 117
: 120
: 978-952-10-9594-8
: 978-952-10-9595-5
: http://www.seismo.helsinki.fi/ilp/lito2018/Lito2018_Abstract_Volume_color.pdf(external)
: https://research.utu.fi/converis/portal/detail/Publication/36385498(external)
We sampled one felsic volcanic rock from the lower part of the Kisko formation and two cordierite-anthophyllite rocks from Orijärvi and Iilijärvi for U-Pb dating. The felsic volcanic rock yield a zircon 207Pb/206Pb weighted average age of ~1.89 Ga. The oldest zircons from the Orijärvi cordierite-anthophyllite rock give a weighted average age of ~1.89 Ga. The monazite from the same sample yield a concordia age of ~1.80 Ga and the xenotime yield a concordia age of ~1.82 Ga. The Iilijärvi cordierite-anthophyllite rock gives a monazite concordia age of ~1.82 Ga. This implies that two metamorphic pulses are recorded in the samples.
