Reversed-Polarity Overprint in Dikes from the Troodos Ophiolite - Implications for the Timing of Alteration and Extension

Paleomagnetic analysis of dikes from the Troodos ophiolite indicates the presence of a well-defined reversed-polarity overprint, an unexpected result given the currently accepted Cenomanian-Turonian age (approximately 88-91 Ma) suggesting formation during the Cretaceous Long Normal Period (83-118 Ma). This reversed-polarity component was apparently acquired prior to tectonic tilting of the dikes, implying that extensional tectonism occurred significantly (>5 m.y.) off axis. Alternatively, the paleomagnetic and field observations may be reconciled if parts of the ophiolite are significantly younger.