Early Carboniferous Unroofing in Western Norway: A Tale of Alkali Feldspar Thermochronology
| Autor: | Torgeir B. Andersen, Elizabeth A. Eide, N. O. Arnaud, Trond H. Torsvik |
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| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | The Journal of Geology. 107:353-374 |
| ISSN: | 1537-5269 0022-1376 |
| Popis: | 40Ar/39Ar thermochronologic data from an extensional detachment zone in western Norway document punctuated late Paleozoic through Mesozoic tectonothermal activity. Diffusion and thermal modeling of alkali feldspars sampled in a profile through the detachment replicate laboratory argon release patterns when feldspars comprise three or four diffusion domains with differing activation energies that represent high‐, intermediate‐, and low‐closure temperatures. These domains correspond to distinct changes in late Paleozoic cooling rates: (1) slow cooling at 0.4°–2.2°C/m.yr. from ca. 380–360 Ma; (2) rapid cooling at ≥15°C/m.yr. in Late Devonian–Early Carboniferous time (360–340 Ma); (3) slow cooling at 0.4°–1.7°C/m.yr. after ca. 340 Ma, with partial argon loss in Permian and Late Jurassic–Early Cretaceous times. The Early Carboniferous rapid cooling event recorded by the feldspars links the western Norway margin to contemporaneous unconformities, regional extension, basin inversion, and igneous activit... |
| Databáze: | OpenAIRE |
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