Temporal‐Geochemical Evolution of the Persani Volcanic Field, Eastern Transylvanian Basin (Romania): Implications for Slab Rollback Beneath the SE Carpathians
AffiliationUniv Arizona, Dept Geosci
MetadataShow full item record
PublisherAMER GEOPHYSICAL UNION
CitationDucea, M. N., Barla, A., Stoica, A. M., Panaiotu, C., & Petrescu, L. (2020). Temporal‐geochemical evolution of the Persani volcanic field, eastern Transylvanian Basin (Romania): Implications for slab rollback beneath the SE Carpathians. Tectonics, 39(5), e2019TC005802.
Rights© 2020. American Geophysical Union. All Rights Reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractThe Quaternary Persani volcanic field (PVF) consists of alkali basalts formed in an extensional basin at the SE end of the Transylvanian basin, near an important anomaly in the European mantle, the Vrancea slab, a seismically active near-vertical lithospheric fragment of debated origin. The PVF is the only basaltic field regionally, has been studied geochemically in the past, and is also known for the presence of abundant mantle xenoliths. Here, we describe new geochemical data on rocks recently dated by Ar-Ar chronometry and show that while we can reproduce virtually all previous results, there is a clear temporal evolution of the magmatic system. There is an increase of over 80 degrees C in temperatures determined by the Si activity thermometer, from 1,300 degrees C to 1,380 degrees C during the similar to 0.5-Myr duration of volcanic activity, which is accompanied by several coherent trends in geochemistry, among which the decrease of Zn/Fe and Sr-87/Sr-86 ratios over time. Earlier, higher Zn/Fe ratios are indicative of a pyroxenite/eclogite-dominated source, which gradually changed to a peridotite-dominated source. These characteristics are typical of a dynamic mantle in which vertical mantle lithosphere tectonics, either due to slab rollback or mantle dripping plays a role and are not consistent with simple decompression melting of asthenosphere. Synchronous adakitic rocks found about 25-30 km east of PVF are presumed to be slab melts and are consistent with the Vrancea slab rollback as the trigger for mantle melting responsible for the PVF.
Note6 month embargo; first published online 16 April 2020
VersionFinal published version
SponsorsUnitatea Executiva pentru Finantarea Invatamantului Superior, a Cercetarii, Dezvoltarii si Inovarii