Palaeomagnetic evidence of a Variscan age for the epigenetic Galmoy zinc–lead deposit,Ireland |
| |
| Authors: | S J Pannalal D T A Symons D F Sangster |
| |
| Institution: | 1. Department of Earth and Environmental Sciences, University of Windsor, Windsor, ON, Canada N9B 3P4;2. 2335 Russvern Drive, North Gower, ON, Canada K0A 2T0 |
| |
| Abstract: | Palaeomagnetism of 273 specimens from 24 sites isolated a well‐defined characteristic remanent magnetization (ChRM) direction on AF and thermal demagnetization in seven host carbonate and 14 ore mineralization sites from the Galmoy Zn–Pb deposit. Thermal decay and saturation remanence data show that the ChRM is carried dominantly by single domain magnetite. Palaeomagnetic field stability tests indicate a post‐brecciation and post‐folding ChRM. The ChRM directions from the host rock and mineralized sites are indistinguishable at 95% confidence and give a palaeopole at 41.5°S, 8.4°W (dp = 1.5°, dm = 3.0°) with an age of 290 ± 9 Ma on the Laurentian apparent polar wander path. This Early Permian age at Galmoy records Variscan orogenesis and suggests an epigenetic model in which mineralization occurred during cooling from the regional Variscan thermal episode. |
| |
| Keywords: | |
|
|
