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Z. dt. Geol. Ges. | 147/1 | S. 1-9, 5 Abb., 3 Tab. | de.Txt. | Stuttgart, März 1996 |
Numerische Stratigraphie permokarbonischer Vulkanite Zentraleuropas.
- Teil II: Westharz. [Numerical stratigraphy of Permocarboniferous volcanic rocks from Central Europe.
Part II:Western Harz.]
Authoren : Hans J. Lippolt & Jürgen C. Hess
Abstract :
40Ar / 39Ar age measurements have been carried out on two biotite and three K-feldspar separations from rhyolitic rocks of the Großer Knollen area (Harz Mountains, Germany). Stratigraphically, the volcanics are assigned to the upper Early Rotliegendes or close to the Early/Late Rotliegendes transition. The biotites yielded 40Ar / 39Ar ages around 290 Ma. The results on the feldspars are 3 to 88 % younger compared to the biotite ages. This can be ascribed to parts of thermally rejuvenated orthoclase components admixed to the sanidine separations.