Abstract
AbstractFour palaeomagnetic sites in Monian pillow lavas of the Gwna Group from Llanddwyn Island, Anglesey, yield statistically‐significant groups of magnetic directions after demagnetising in low fields. A palaeomagnetic pole of 57°E, 16° S is derived after dip correction assuming no plunge components, and is believed to apply to the time of formation of the pillow lavas (ca. 600 m.y.). By contrast to young pillow lavas these rocks have poor magnetic stability and low Köenigsberger ratios although petrologic features are comparable; this is believed to be due to replacement of the finer grain size fractions of the titanomagnetite. Five of the seven dolerite dykes cutting the Monian rocks here yield pole positions close to those of Upper Silurian to Lower Devonian rocks from elsewhere in Britain confirming that they are Palaeozoic in age.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
