Contemporaneous opening of the Alpine Tethys in the Eastern and Western Alps: Constraints from a Late Jurassic gabbro intrusion age in the Glockner Nappe, Tauern Window, Austria
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Date
2021
Journal Title
Journal ISSN
Volume Title
Publisher
Springer
Abstract
Metabasic rocks of the ophiolitic sequences of the Glockner Nappe and Eclogite Zone in the south-central Tauern Window,
Austria, reveal important insights into rifting and spreading of the Alpine Tethys. U–Pb dating of magmatic zircons yields a
concordant 157±2 Ma crystallization age for the precursor of a coarse-grained metagabbro from the Glockner Nappe. The
Late Jurassic intrusion age is coeval with mafc plutonic activity in the Western and Central Alps. Although Penninic ophiolitic sequences in tectonic windows of the Eastern Alps are usually disrupted, an ocean–continent transition setting can be
reconstructed for the Glockner Nappe, similar to many ophiolites in the Liguria–Piemont domain in the Western and Central
Alps. Together, these observations strongly suggest a formation in the Liguria–Piemont branch of the Alpine Tethys and are
inconsistent with a formation in the Valais domain. This fnding has important implications for paleogeographic reconstructions of the Penninic realm in the Eastern Alps. Whereas the Glockner Nappe metagabbro and metabasalts clearly reveal
their depleted mantle origin, the metabasic rocks of the Eclogite Zone record a more complex formation history involving
depleted mantle melting and crustal assimilation in a continental margin setting.
Description
Keywords
Alpine Tethys, Tauern window, Metagabbro, Austria
Citation
Gleißner, P. et al. (2021). Contemporaneous opening of the Alpine Tethys in the Eastern and Western Alps: Constraints from a Late Jurassic gabbro intrusion age in the Glockner Nappe, Tauern Window, Austria. International Journal of Earth Sciences, 110, 2705–2724. https://doi.org/10.1007/s00531-021-02075-z