This data set is Part 9 of a series of data sets dealing with the composition of accessory minerals from felsic igneous rocks compiles chemical data for monazite-(Ce), xenotime-(Y) and zircon from several, late-Variscan granite occurrences in the Aue-Schwarzenberg Granite Zone (ASGZ) located in the Western Erzgebirge−Vogtland metallogenic province of Germany. The rocks treated in this data set encompass the biotite granites of the Aue suite, Bernsbach and Beierfeld, and the two-mica granites from Lauter and the Schwarzenberg suite.
The data set contains the complete pile of electron-microprobe analyses for monazite-(Ce) (MONA-ASGZ-2021), xenotime-(Y) (XENO-ASGZ-2021) and zircon (ZIRC-ASGZ-2021). Tables are presented as Excel (xlsx) resp. machine-readable csv formats. The content of the tables and further information on the granites and regional geology are provided in the data description file and the supplementary literature.
The ASGZ (about 325 Ma) is located within the deep-reaching Gera-Jáchymov Fault Zone and includes the F-poor biotite granites of the Aue suite (including the granite occurrences at Schlema-Alberoda, Aue, Auerhammer, and Schneeberg), Bernsbach and Beierfeld, and the F-poor two-mica granites of the Schwarzenberg suite (covering the granite occurrences at Schwarzenberg, Neuwelt, and Erla) and Lauter (Fig. 1). The granite encountered by drilling at the village Burkersdorf does not represent an independent intrusion, but is instead a subsurface exposure of the westerly Kirchberg granite, at the contact to the metamorphic country rock.
The petrography, mineralogy, geochemistry, isotopic composition, and geochronology of the ASGZ rocks have been comprehensively described by Förster et al. (2009). The paper of Förster (2010) reports a selection of results of electron-microprobe analyses of monazite-(Ce), xenotime-(Y) and zircon, but the bulk of the obtained data remained unpublished. This paper also provides a mineralogical mass-balance calculation for the lanthanides and actinides of the Aue and Schwarzenberg granite suites and a selection of back-scattered electron images displaying the intergrowths, texture, and alteration patterns of the radioactive and REE-Y-Zr-bearing accessory species.
The F-poor biotite granites of the ASGZ are weakly to mildly peraluminous (A/CNK = 1.07 – 1.14; SiO2 = 70 – 76 wt.%). The F-poor two-mica granites are mildly to strongly peraluminous (A/CNK = 1.17 – 1.26) and cover a similar range in silica concentration (69 – 77 wt%). From this granite group, only more fractionated, higher evolved sub-intrusions were subjected to the study of accessory-mineral composition. Some granites of this zone are genetically related with ortho-magmatic W-Mo veins and para-magmatic vein-type U mineralization.
This data set is Part 2 of the compiles whole-rock chemical data for late-Variscan low-F biotite and two-mica granites in the German Erzgebirge, in the Saxothuringian Zone of the Variscan Orogen.
The group of F-poor biotite granites is represented by the composite massifs of Kirchberg and Niederbobritzsch, the Plohn Granite Suite (PGS), the Aue Granite Suite (AGS), and the subsurface granites of Beiersdorf und Bernsbach. For the group of two-mica granites, compositional data for the multi-stage Bergen massif and the granites from Lauter and Schwarzenberg are reported (Figure 1). Crystal-melt fractionation was the dominant process controlling the evolution of bulk composition in the course of massif/pluton formation. However, metasomatic and hydrothermal processes involving late-stage residual melts and high-T late- to post-magmatic fluids became increasingly more important in highly evolved units and have variably modified the abundances of mobile elements. Interaction with the various metamorphic country rocks and infiltration of meteoric low-T fluids have further disturbed the initial chemical patterns in the endocontact zones and zones influenced by surface weathering.
The data set reports whole-rock geochemical analyses for enclaves, granites, aplites, endocontact rocks, and some facial varieties. The data are presented as Excel (xlsx) and machine-readable txt formats. The content of the excel sheet and further information on the granites and regional geology are provided in the data description file.