DOI: 10.5880/digis.2023.004
title: Whole-rock geochemical analyses (major and minor elements, REE) of highly deformed and metamorphosed rocks of the Middle and Eastern Erzgebirge nappe stacks
title: 1 Gesamtgesteins-Geochemie (Haupt-, Spurenelemente, REE) an hoch-deformierten und metamorphosierten Gesteinen der Mittel- und Osterzgebirgirgischen Deckenstapel

description: The data presented are whole-rock geochemical analyses (major and minor elements, REE) of highliy deformed and metamorphosed rocks of the Middle and Eastern Erzgebirge nappe stacks. Geochemical discrimination was used to identify the protolith nature of a sample series representing metasedimentary, metagranitoidic, metarhyolitic, and metabasaltic rock types. Discrimination between para- and orthogneisses was also supported by mathematical factor analysis. According to new geochronological data, ages of the sample series range between Neoproterozoic to Ordovician. 
 
Analyses with different methods (ICP, AAS, XRF, OES, WET) were made between 1979 and 1991 in different laboratories of the German Democratic Republic (GDR) and the early GFZ German Research Centre for Geosciences. Economical constraints limited the capacity of and access to labs, and also available techniques in the GDR - limiting the spectrum of elements to be analysed, especially that of REE, as well. Switching from lab to lab (see table) became a neccessary tool. Despite these problems, all data proved to be comparable. This also applies in comparison to data from later used techniques (ICP, from 1991 on) on some additional sample material, regardless of its higher resolution. In few cases, detection limits have not been communicated (see template). The data are reported with the EarthChem Templates (https://doi.org/10.26022/IEDA/112263). 
 
German title: Gesamtgesteins-Geochemie (Haupt-, Spurenelemente, REE) an hoch-deformierten und metamorphosierten Gesteinen der Mittel- und Osterzgebirgirgischen Deckenstapel
description: The Erzgebirge rock units are part of the the highly deformed and metamorphosed allochthonous domain of Saxo-Thuringia, Germany. Forming several repetitive structural units of inverse metamorphic pressure-temperature conditions, they partly overly, partly include Cadomian basement rocks. The whole stack is interpreted as part of the Variscan thrust-and-fold belt with metamorphic peak ages from 360 Ma (eclogites) to 340 - 330 Ma (felsic igneous and sedimentary rocks). 
 
A former lithostratigraphic concept, which was followed by the original purpose of geochemical discrimination has been revised long since (Schmädicke et al, 1992; Rötzler, 1995; Mingram, 1996; Rötzler & Plessen, 2010; Kemnitz et al, 2017). The geochemical data, however, are well appropriate to differentiate between the metamorphic rocks from different structural units and of different deformational and metamorphic character, and prove their common protoliths. Modern crystallization ages of granitic to granodioritic orthogneisses range between 550 - 530 Ma, while identified metasedimentary members show maximum sedimentation ages between 580 - 560 Ma. Both rock types correlate well in age and geochemistry to the Neoproterozoic turbiditic greywackes and the Cadomian granodioritic intrusions of the Lusatian Massif (Tichomirowa, 2002). Rhyolithic orthogneisses show Ordovician ages, dated 490 - 480 Ma. Discrimination of the metabasic rocks (eclogites to amphibolites) plots in the field of ocean-floor basalts, in correspondence with the modern concept.