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of electron-microprobe analyses of monazite-(Ce), xenotime-(Y) and zircon, but the bulk of the obtained data remained unpublished.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 the part 8 of a series reporting chemical data for accessory minerals from felsic igneous rocks. Compositional data were acquired by electron-probe microanalysis (EPMA) between about 1995 and 2005 on surface rocks and borehole samples. This data set assembles the results of EPMA of fluorapatite from felsic rocks representing three groups of granites in the Erzgebirge−Vogtland metallogenic province of Germany emplaced in the late Carboniferous: F-poor biotite granites, F-poor two-mica granites, and P-F-rich Li-mica granite. In these rocks, fluorapatite is typically omnipresent. It has to be noted that apatite has not yet been in the focus of mineralogical studies of the granites in this province and a comprehensive survey of its compositional signature and variability in space and time is still pending. However, the data listed in this data set provide a valuable glimpse into the similarities and differences in apatite chemistry between geochemically distinct felsic rocks, and into the evolution in composition from early to late crystallizing apatite populations. The data underpin that apatite is a sensitive monitor of the compositional properties of the media (melts and fluids) from which it was deposited or with which it interacted. Apatite from the studied rocks is basically fluorapatite with little or no Cl and OH detected respectively inferred. Elemental variations are observed at various scales, i.e., between granite groups, subsequently crystallized sub-intrusion within composite massifs, grains present in a single thin section, or between the center and the rim of a particular grain. These variations in particular refer to the following elements: Mn, Fe, Na, and the rare-earth elements (REE). For example, measured Mn concentrations range from 0.15 to 8.8 wt% MnO. The data set contains the complete pile of electron-microprobe analyses for fluorapatite (APAT-ERZ-2020). The data are presented as Excel (xlsx) and tab-delimited text (txt) formats. The content of the tables and further information on the granites and regional geology are provided in the data description file.
Part seven of a series of data sets dealing with the composition of accessory minerals from felsic igneous rocks reports chemical data for monazite-(Ce) and zircon from eight occurrences of high-Si felsic microgranites/rhyolites in the Erzgebirge−Vogtland metallogenic province of Germany, which possibly emplaced between 305 and 295 Ma. The subvolcanic rocks are discriminated into three groups according to whole-rock geochemistry. Mineral data are acquired between about 1995 and 2005 on surface rocks and borehole samples. The data set contains the complete pile of electron-microprobe analyses for monazite-(Ce) (MONA-VOLC-2020) and zircon (ZIRC-VOLC-2020). All tables are presented as Excel (xlsx) and 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. Information on xenotime-(Y), which is commonly rare and did not precipitate in all rhyolites, and rhabdophane-(Ce), which was observed only ones as alteration product of monazite-(Ce), is provided elsewhere (cf. data description file).
This data set is the 4th contribution of a series reporting chemical data for accessory minerals from felsic igneous rocks. It deals with two late Variscan biotite-granite massifs emplaced in the Saxothuringian Zone of the Variscan Orogen (Erzgebirge−Vogtland metallogenic province) in Germany. Mineral compositions were measured by electron-microprobe on surface rocks and borehole samples.The data set assembles the results of electron-microprobe spot analyses of primary and secondary allanite-(Ce), monazite-(Ce), xenotime-(Y) and zircon from the multi-phase biotite-granite plutons of Kirchberg (KIB, Western Erzgebirge) and Niederbobritzsch (NBZ, Eastern Erzgebirge). Both plutons comprise several, compositionally and texturally distinct sub-intrusions, contain locally centimeter- to decimeter-sized co-genetic enclaves and xenoliths, and are cross-cut by chemically distinct, fine-grained aplitic dikes. These late-Variscan (c. 325 Ma) granites are moderately to highly evolved and (not considering enclaves) span the SiO2-range (in wt%) 67.0-77.4 (KIB) and 66.8-76.2 (NBZ). The granites are weakly peraluminous (A/CNK = 1.04−1.11 for KIB and 0.99-1.10 for NBZ) and of transitional I−S-type affinity.Formation of primary allanite-(Ce) was restricted to the least-evolved subintrusions KIB1 and NBZ1 of both massifs. All other granites contain monazite-(Ce) as predominant LREE host. Magmatic allanite-(Ce) is variably altered and characterized by totals <100 wt%, implying the presence of several wt% water in the structure. Synchysite-(Ce) constitutes one of its alteration minerals. The Kirchberg massif hosts a second sub-facies of KIB1 that contains monazite instead of allanite as primary species. Severe alteration of this granite facies gave rise to partial or complete dissolution of part of the monazite accompanied by formation of allanite-epidote solid solutions as alteration product. Monazite-(Ce) displays large variations in Th versus REE concentrations even at thin-section scale. Incorporation of Th is mainly governed by the huttonite substitution Th^4+ + Si^4+ = REE^3+ + P^5+. Thorium concentrations span the range 1.33 – 41.8 wt.% ThO2. Xenotime-(Y) does not occur in KBI1 and NBZ1, but crystallized in all other subintrusions. Notable is the predominance of the heaviest REE Er-Lu (normalized to chondrite).The data set contains the complete pile of electron-microprobe analyses for the four accessory minerals allanite-(Ce) (ALLA-KIB-NBZ2019), monazite-(Ce) (MONA-KIB-NBZ2019), xenotime-(Y) (XENO-KIB-NBZ2019) and zircon (ZIRC-KIB-NBZ2019). All tables are presented as Excel (xlsx) and machine-readable csv formats. The content of the tables and further data description are given in the data description file, together with BSE images of primary and secondary allanite-(Ce) from the KIB1 subintrusion.
This data set is the 5th fifth part of a series reporting chemical data for accessory minerals from felsic igneous rocks. Most data refer to plutonic rocks from the Saxothuringian Zone of the Variscan Orogen (Erzgebirge−Vogtland metallogenic province) in Germany performed between about 1995 and 2005 on surface rocks and borehole samples.This data set assembles the results of electron-microprobe spot analyses of monazite-(Ce), xenotime-(Y) and zircon from two concealed, genetically distinct occurrences of evolved, F-rich Li-mica granite, that are the transitional S-I-type P-rich granites of Pobershau-Satzung (POB-SZU) and the P-poor granite of Seiffen (SEI), a representative of the class of aluminous A-type granites.Of all three species, grains of abnormal composition are present, reflecting the evolved nature and specific composition of their granite hosts. The most striking differences in mineral composition between the two granite occurrences are displayed by a) the substitution reaction governing the incorporation of Th+U in monazite (cheralite substitution, Ca(Th,U)REE-2, in POB-SZU and huttonite substitution, Th(U)SiREE-1P-1, in SEI) and b) the chondrite-normalized REE patterns of xenotime (peaking at Tb-Dy in POB-SEI and Yb-Lu in SEI).The data set contains the complete pile of electron-microprobe analyses for monazite-(Ce) (MONA-POB-SEI-NBZ2019), xenotime-(Y) (XENO-POB-SEI2019), and zircon (ZIRC-POB-SEI2019). All tables are presented as Excel (xlsx) and 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.
This data set is the second part of a series reporting chemical data for accessory minerals from felsic igneous rocks. Most data refer to plutonic rocks from the Saxothuringian Zone of the Variscan Orogen (Erzgebirge−Vogtland metallogenic province) in Germany performed between about 1995 and 2005 on surface rocks and borehole samples. This data set assembles the results of electron-microprobe spot analyses of monazite-(Ce), xenotime-(Y) and zircon from the Li-mica granite massif of Eibenstock. This massif is composed of several, compositionally and texturally distinct sub-intrusions. Least evolved members of the fractionation series are exposed as variably sized enclaves. The pluton is cross-cut by fine-grained aplitic dikes. These late-Variscan (c. 318−320 Ma) granites are highly evolved, rich in Si (72.4-75.8 wt% SiO2), F, P, Li, Rb, Cs, and Sn, mildly to strongly peraluminous (A/CNK = 1.14−1.35), of transitional S−I-type affinity, and spatially and genetically associated with coeval significant Sn−W−(Mo) mineralization. Most notably, a comparatively large population of grains of all three species is distinguished by abnormal composition, reflecting the chemically evolved nature of their hosts. Probe data indicate that the composition of monazite-(Ce) and zircon changes with fractionation-driven evolution of magma chemistry. Monazite-(Ce) composition extends over an abnormally large range. In the course of magma differentiation, mineral chemistry evolves towards enrichment Th and U and development of flattened and kinked chondrite-normalized LREE patterns, with negative anomalies at La or Nd, or both (also known as lanthanide tetrad effect). Many grains are so rich in Th that they classify as cheralite-(Ce). The concentrations (in oxide wt%) of the radionuclides Th and U maximizes to 51.7 and 5.3, respectively. The maximum concentration of Y amounts to 4.7 wt% Y2O3. Composition of zircon displays a large variability. A greater number of grains or domains are distinguished by abnormal enrichment in (in oxide wt%) P (up to 9.6), Th (up to 12.2), U (up to 8.7), Hf (up to 5.6) Al (up to 2.2), Sc (up to 2.0), Y (up to 7.0), HREE and Y. Enrichment in these elements is usually associated with low analytical totals, reflecting precipitation from volatile-rich magmas and/or their interaction with, and alteration by, late-magmatic fluids. Xenotime-(Y) chemistry is comparatively little sensitive to changes of Eibenstock-magma composition relative to what has been observed for monazite-(Ce) and zircon. The U concentrations in xenotime-(Y) are generally high and maximize to 6.7 wt% UO2. Chondrite-normalized MREE and HREE patterns preferentially in xenotime-(Y) from more evolved magma batches mimic that of their host granites in that they are (a) inclined from Tb-Dy towards Lu, (b) partially evolved the lanthanide tetrad effect, and (c) display above-CHARAC Y/Ho ratios up to 41. The data set published here contains the complete pile of data acquired for these three accessory minerals. Data are provided as three separate excel files, one for each species (monazite-(Ce); xenotime-(Y); zircon). The data are described in detail in the associated data description file.
This data set compiles the results of electron-microprobe spot analyses of monazite-(Ce), xenotime-(Y) and zircon from the two-mica granite massif of Bergen. This massif is composed of compositionally and texturally distinct sub-intrusions, which occasionally contain dark microgranular enclaves and are cross-cut by aplitic dikes. These late-Variscan (c. 325 Ma) granites are evolved, Si-rich (70.6−76.3 wt% SiO2), of transitional I−S-type affinity, and spatially associated with minor W−Mo mineralization.Data indicate that the composition of monazite-(Ce) and zircon changes with fractionation-driven evolution of magma chemistry. In the course of magma differentiation, monazite-(Ce) chemistry evolves towards enrichment Th and U and development of “irregular” chondrite-normalized LREE patterns, with negative anomalies at La or Nd, or both. Monazite-(Ce) precipitated from more evolved magma batches also tends to be richer in MREE and HREE relative to that occurring in early-stage granites. Composition of zircon in more differentiated sub-intrusions displays a large variability. A greater number of grains or domains are distinguished by enrichment in P, Hf, Al, Sc, Y+HREE and low analytical totals, reflecting their crystallization from volatile-rich magmas and/or their interaction with late-magmatic fluids. Xenotime-(Y) chemistry is comparatively insensitive to changes of magma composition that characterized the Bergen massif.The data set published here contains the complete pile of elecron-microprobe analyses for the three accessory minerals monazite-(Ce) (MonaBrg2018), xenotime-(Y) (XenoBRG2018) and zirkon (ZircBRG2018). All tables are presented as Excel (.xlsx) and csv formats. The content of the tables and further data description are given in the data description file.
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