A U/Pb age for the Sulitjelma Gabbro, North Norway: further evidence for the development of a Caledonian marginal basin in Ashgill–Llandovery time
Abstract The Sulitjelma Gabbro in the central Norwegian Caledonides has been dated with the U/Pb zircon/sphene method to 437±2 Ma. Geological relationships as well as trace-element geochemistry and Nd and Sr isotopic compositions suggest that the gabbro and associated dyke swarms and pillow lava for...
| Published in: | Geological Magazine |
|---|---|
| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Cambridge University Press (CUP)
1991
|
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1017/s0016756800018331 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800018331 |
| Summary: | Abstract The Sulitjelma Gabbro in the central Norwegian Caledonides has been dated with the U/Pb zircon/sphene method to 437±2 Ma. Geological relationships as well as trace-element geochemistry and Nd and Sr isotopic compositions suggest that the gabbro and associated dyke swarms and pillow lava formed during the initial stages of back-arc spreading. The age constrains the timing of juxtaposition of an older island-arc terrane and continental-margin lithologies exposed within the Caledonian nappes. The age of the gabbro is similar to that of the Solund–Stavfjord Ophiolite in west Norway, and confirms that spreading-related magmatism and marginal-basin development took place along the margin of Iapetus in late Ordovician–early Silurian times. |
|---|