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 t he presence of a well-defined reversed-polarity overprint, an unexpect ed result given the currently accepted Cenomanian-Turonian age (approx imately 88-91 Ma) suggesting formation during the Cretaceous Long Norm al Period (83-118 Ma). This reversed-polarity component was apparently acquired prior to tectonic tilting of the dikes, implying that extens ional tectonism occurred significantly (>5 m.y.) off axis. Alternative ly, the paleomagnetic and field observations may be reconciled if part s of the ophiolite are significantly younger.