Geochronology, geochemistry and tectonic implications of Variscan granitic and dioritic rocks from the Odenwald-Spessart basement, Germany

Will TM, Schmädicke E, Ling XX, Li XH, Li QL (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Lithos Elsevier

Book Volume: 404-405

DOI: 10.1016/j.lithos.2021.106454

Abstract

New zircon U-Pb-Hf-O isotope, whole rock geochemical and Sr-Nd-Pb isotope geochemical data of Variscan felsic to intermediate rocks from the Odenwald-Spessart basement, Mid-German Crystalline Zone, Germany are presented. Peraluminous, high-K calc-alkaline S-type granite in the eastern Odenwald basement (Group 1 rocks) formed by partial melting of the lower crust at c. 425 Ma. Their high-K calc-alkaline composition indicates the presence of sedimentary and/or metasomatized lithospheric mantle material during formation of the melts. The protolithic melts of metaluminous, medium-to high-K calc-alkaline I-type granodiorite and diorite of the Spessart and western Odenwald basement as well as the Neustadt (Odenwald) outlier (Group 2 rocks) formed by partial melting of the upper mantle at c. 340 Ma. The melt source was enriched through previously subducted Mesoproterozoic sedimentary material. Eastern Odenwald basement leucocratic gneiss have zircon with ages ranging from 2803 Ma to 336 Ma and main age peaks between 620 and 570 Ma and 360 and 330 Ma. The presence of numerous >1800 Ma old zircon and a prominent age gap between 1800 and 1000 Ma imply a Gondwanan zircon source and indicate the presence of Cadomian material in the Odenwald-Spessart basement. Group 2 diorite is exposed over a distance of at least 60 km from the easternmost Spessart to the westernmost Odenwald and is expected to underlie the eastern Odenwald basement. We suggest that Group 2 diorite formation was related to the presence of a mantle plume, which was also responsible for the widespread Carboniferous magmatism and the associated high-temperature metamorphism in the Odenwald-Spessart basement and other areas of the Variscan orogen.

Authors with CRIS profile

Esther Schmädicke Professur für Mineralogie

Involved external institutions

Julius-Maximilians-Universität Würzburg DE Germany (DE) Chinese Academy of Sciences (CAS) / 中国科学院 CN China (CN)

How to cite

APA:

Will, T.M., Schmädicke, E., Ling, X.-X., Li, X.-H., & Li, Q.-L. (2021). Geochronology, geochemistry and tectonic implications of Variscan granitic and dioritic rocks from the Odenwald-Spessart basement, Germany. Lithos, 404-405. https://doi.org/10.1016/j.lithos.2021.106454

MLA:

Will, Thomas M., et al. "Geochronology, geochemistry and tectonic implications of Variscan granitic and dioritic rocks from the Odenwald-Spessart basement, Germany." Lithos 404-405 (2021).

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