✦ LIBER ✦
Uranium-lead isotopic evidence from zircons for lower Palaeozoic tectonic activity in the Austroalpine Nappe, the Eastern Alps
✍ Scribed by R. A. Cliff
- Book ID
- 104745552
- Publisher
- Springer
- Year
- 1980
- Tongue
- English
- Weight
- 776 KB
- Volume
- 71
- Category
- Article
- ISSN
- 0010-7999
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✦ Synopsis
U/Pb isotopic data for two zircon suites are presented :
(1) a pre D1 tonalite gneiss gives an age of 443 + 13 _ 16 m.y.
(2) a post D1 leucogranite gneiss gives 427+~ ~ m.y. Both zircon suites contain a minor inherited pre-Cambrian component. The data confirm a lower Palaeozoic age for the major, fabric-forming D~ event. Hercynian metamorphism which was sufficient to reset muscovite K/Ar ages to ca. 290 m.y. had little effect on the zircons. The possible importance of lower Palaeozoic orogeny in southern Europe and the uncertainties in regional palaeogeography are emphasised.