Other (O2)

Geochronology, geochemistry and structural setting of the Uunimäki gold mineralisation, SW Finland




List of AuthorsTuomas Leskelä, Jaakko Kara, Iiro Pitkälä, Pietari Skyttä, Markku Väisänen, Markku Tiainen, Hanna Leväniemi, Janne Hokka, Yann Lahaye

EditorsIlmo Kukkonen, Suvi Heinonen, Hanna Silvennoinen, Fredrik Karell, Elena Kozlovskaya, Arto Luttinen, Kaisa Nikkilä, Vesa Nykänen, Markku Poutanen, Pietari Skyttä, Eija Tanskanen, Timo Tiira and Kati Oinonen

Conference nameLITHOSPHERE

Publication year2018

Book title *LITHOSPHERE 2018: TENTH SYMPOSIUM ON STRUCTURE, COMPOSITION AND EVOLUTION OF THE LITHOSPHERE: PROGRAMME AND EXTENDED ABSTRACTS

Title of seriesREPORT

Number in series67

Start page65

End page68

ISBN978-952-10-9594-8

eISBN978-952-10-9595-5

URLhttp://www.seismo.helsinki.fi/ilp/lito2018/Lito2018_Abstract_Volume_color.pdf

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/37200266


Abstract

The Uunimäki gabbro was studied by zircon U-Pb geochronology which yielded an age of ~1.89 Ga, making it one of the oldest plutonic rocks in the Häme Belt. Geochemical analysis of the gabbro reveals that it lacks several characteristics for typical subduction zone rocks: (i) it does not have a negative Ta-Nb anomaly compared to average NMORB-composition, (ii) it shows a rather unfractionated REE pattern, (iii) it lacks clear enrichment of fluid-mobile elements (e.g. Ba, Rb, Th, Pb). Structurally, the Uunimäki gabbro is located at the intersection of several regional features: (i) steep NE-plunging folds, (ii) a ENE-WSW-trending deformation zone immediately to the north and (iii) a large N-S-trending deformation zone to the west. The gabbro itself has been deformed under both brittle and ductile conditions by primarily NW-SE-trending faults and shears.


Downloadable publication

This is an electronic reprint of the original article.
This reprint may differ from the original in pagination and typographic detail. Please cite the original version.




Last updated on 2022-07-04 at 17:08