Significance of ~ 1.5 Ga zircon and monazite ages from charnockites in southern Lithuania and NE Poland |
| |
| Institution: | 1. School of Geosciences, University of the Witwatersrand, Johannesburg 2001, South Africa;2. Department of Geology, University of Johannesburg, Johannesburg 2001, South Africa;3. Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka 237-006, Japan;1. Department for Geology (Geological Survey), Saxon State Office for Environment, Agriculture, and Geology, Halsbrücker Straße 31a, D-09599 Freiberg, Germany;2. Institute for Geology, TU Bergakademie Freiberg, Bernhard-von-Cotta-Straße 2, D-09599 Freiberg, Germany;3. Institute for Mineralogy and Crystallography, University of Vienna, Althanstraße 14 (UZA2), A-1090 Wien, Austria;4. Saxony-Anhalt State Survey for Geology and Mining, Köthener Straße 34, D-06118 Halle, Germany;5. Institute for Mineralogy, TU Bergakademie Freiberg, Brennhausgasse 4, D-09596, Germany;6. Museum für Naturkunde Berlin, Leibniz Institute for Research on Evolution and Biodiversity, Invalidenstraße 43, D-10115 Berlin, Germany |
| |
| Abstract: | The presence of 1.52–1.50 Ga charnockites from the anorthosite–mangerite–charnockite–granite (AMCG) Mazury complex in southern Lithuania and NE Poland, in the western East European Craton (EEC) is revealed by secondary ion mass-spectrometry (SIMS) and EPMA geochronology. Early 1.85–1.82 Ga charnockites are related to major orogeny in the region whereas the newly studied charnockites intrude the already consolidated crust. The 1.52–1.50 Ga charnockite magmatism (SIMS data on zircon) was followed by high-grade metamorphism (EPMA data on monazite), which strongly affected the surrounding rocks. The 1.85–1.81 Ga zircon cores in Lazdijai and 1.81 Ga monazite domains in the Lanowicze charnockites represent the protolith age of a volcanic island arc. The 1.52–1.50 Ga charnockite magmatism and metamorphism are likely related to the distal, Danopolonian, orogeny further to the west, at the margin of Baltica. The c.1.52–1.50 Ga AMCG magmatism and metamorphism in the western EEC as well as the paired accretionary-rapakivi suites in Amazonia, may be the inboard manifestations of the same early Mesoproterozoic orogeny associated with the juxtaposition of Amazonia and Baltica during the amalgamation of the supercontinent Columbia. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
