U/Pb and Ar/Ar geochronology of anorogenic granite magmatism of the Mazury complex, NE Poland

The Mazury complex of northeastern Poland forms a 200 km long, E/W trending anorthosite/mangerite/ charnockite/granite belt derived from bimodal, multiphase anorogenic magmatism and is similar to the classic anorogenic complexes of the Fennoscandian Shield (e.g. Wiborg, Salmi and Ragunda). The compl...

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Bibliographic Details
Main Authors: Wolfgang Dörr A, Zdzislaw Belka B, Dirk Marheine C, Janina Schastok A, Pablo Valverde-vaquero A, Janina Wiszniewska D
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2002
Subjects:
Fennoscandia
Fennoscandian
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.595.9321
http://homepages.uni-tuebingen.de/belka/papers/Mazury_Complex.pdf
Description
Summary:The Mazury complex of northeastern Poland forms a 200 km long, E/W trending anorthosite/mangerite/ charnockite/granite belt derived from bimodal, multiphase anorogenic magmatism and is similar to the classic anorogenic complexes of the Fennoscandian Shield (e.g. Wiborg, Salmi and Ragunda). The complex is dominated by felsic and intermediate rocks ranging from quartz monzonite through granodiorite and monzodiorite to diorite and is associated with anorthosite/norite plutons (Suwalki, Sejny and Ketrzyn). The ore deposits in Suwalki have 15599/37 and 15569/94 Ma Re/Os ages with a high initial 187Os/188Os reflecting crustal signature (Morgan et al. Miner. Deposita 35 (2000) 391). The Mazury complex crosscuts granulite and amphibolite facies metamorphic units (Pomeranian, Ciechanów and Mazovian), which are correlated with the Svecofennian rocks of Fennoscandia. U/Pb geochronology of single zircons and titanite fractions indicates that the felsic igneous activity of the Mazury complex occurred during a /25 m.y. period in at least three distinct pulses: (1) Krasnopol monzodiorite has a zircon 207Pb/206Pb age of 15259/4 Ma and titanite fractions dated at 15269/11 Ma (mean 207Pb/206Pb age), zircons from Bartoszyce quartz monzonite are concordant at 15229/2 Ma; (2) Boksze diorite has two concordant zircons with an age of 15129/1.1 Ma; (3) the youngest episode is represented by a 15029/2 Ma quartz monzonite from Goldap and a 14999/4 Ma quartz monzonite from Bartoszyce (Claesson et al., MAEGS meeting, St. Petersburg, 1995, p. 21). Zircon with a 207Pb/206Pb age of 15679/

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