U-Pb geochronology of pegmatites from the Rhodope Metamorphic Complex

The present study reports new U-Pb LA-ICP-MS isotope ages based on zircons and titanites. The majority of the selected for investigation pegmatite bodies are hosted by the variegated units, part of the Middle Allochthon of the Rhodope metamorphic complex. Most of the studied pegmatites are concordant and some are oblique with respect to the metamorphic foliation. In the majority of cases, the direct genetic link to particular magmatic intrusions is not obvious. Major constituents in the mineral composition are feldspars – both plagioclase and K-feldspar, quartz and occasionally micas. Compositionally, the zircons from pegmatites reveal increased U content. The geochronological data is complemented by ages of the host metamorphic basement. U-Pb geochronology on zircon and titanite established that most of the studied pegmatites are formed in the Late Cretaceous – Early Paleocene (66–55 Ma) with slight exceptions ~100 Ma (on the Early/Late Cretaceous boundary). The obtained U-Pb dating confirm the younger Cenozoic age of the pegmatites from the Rhodope metamorphic complex reported by other authors.