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This data set is the sixth part of a series reporting chemical data for accessory minerals from felsic igneous rocks. It assembles the results of electron-microprobe spot analyses of monazite-(Ce), xenotime-(Y) and zircon from the late-Variscan granites of the Fichtelgebirge/Smrčiny in the Saxothuringian Zone of the Variscan Orogen in Germany/ Czech Republic.The granites form an older, Namurian intrusive complex (OIC-p and OIC-e) and a younger, post-Westphalian intrusive complex (YIC-1 and YIC-2). Both complexes have distinct radioactive accessory-mineral assemblages and compositions. The OIC-p biotite monzogranites contain monazite-(Ce) and minor thorite, but apparently lack magmatic xenotime-(Y) and uraninite. The more evolved OIC-e two-mica granites bear monazite-(Ce) occasionally rich in Th (up to 21 wt% ThO2) and U (8 wt% UO2), xenotime-(Y) of moderate U content (< 3.3 wt% UO2), and uraninite poor in Th and the REE. The most fractionated YIC Li-mica granites (YIC-2) may contain monazite extremely high in Th (40.5 wt% ThO2) and U (8.6 wt% UO2), which classify as cheralite-(Ce), xenotime-(Y) rich in U (6.3 wt% UO2) and such with elevated Y/Ho ratios (up to 48), and also a Th–REE-poor uraninite. In these granites, zircon may contain up to 5 wt% HfO2 and display low, fractionated Zr/Hf ratios (down to 10).The data set contains the complete pile of electron-microprobe analyses for monazite-(Ce) (MONA-FICH-2020), xenotime-(Y) (XENO-FICH-2020), and zircon (ZIRC-FICH-2020). All tables are presented as Excel (xlsx) and machine-readable txt 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 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 1st part of a mini-series assembling whole-rock chemical data for late-Variscan granites of the Erzgebirge-Vogtland metallogenic province in the German Erzgebirge, in the Saxothuringian Zone of the Variscan Orogen, which is dedicated to the group of P-F-rich Li-mica granites. Listed are data from the massifs/plutons of Eibenstock in the western Erzgebirge and Annaberg, Geyer, Pobershau, and Seiffen in the central Erzgebirge (Figure 1). All these occurrences represent composite bodies made-up of texturally and geochemically distinct, but cogenetic sub-intrusions, which are associated with intra- und perigranitic aplitic dykes, pegmatitic schlieren, and frequently mineralized quartz veins and greisens (Tables 1-3). These granites exhibit moderately to strongly elevated concentrations of P, F, Li, Rb, Cs, Ta, Sn, W and U, but are low to very low in Ti, Mg, V, Sc, Co, Ni, Sr, Ba, Y, Zr, Hf, Th, and the REEs. Crystal-melt fractionation was the dominant process controlling the evolution of bulk composition in the course of massif/pluton formation. However, metasomatic processes involving late-stage residual melts and high-T late- to postmagmatic fluids became increasingly more important in highly evolved units and have variably modified the abundances of mobile elements (P, F, Li, Rb, Cs, Ba, Sr). Interaction with the various country rocks and infiltration of meteoric low-T fluids have further disturbed the initial chemical patterns. The data set reports whole-rock geochemical analyses for granites, aplites, and endocontact rocks obtained for the massifs/plutons of Eibenstock, Pobershau, Satzung, Annaberg, and Geyer. Data are provided as separate excel and csv files. The content of the excel sheet and further information on the granites and regional geology are provided in the data description file.
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.
This data set is the third of a series reporting chemical data for accessory minerals from felsic igneous rocks. It compiles the results of electron-microprobe spot analyses of monazite-(Ce) from various Paleoproterozoic granitoids and spatially associated gneisses located in the wider Fort McMurray area in northeastern Alberta, Canada. The data were generated in connection with the Master of Science thesis of Nathanial John Walsh (Walsh 2013) at the Department of Earth and Atmospheric Sciences of the University of Alberta, Edmonton, Canada, but remained unpublished. The thesis was part of the Helmholtz - Alberta - Initiative (HAI) between the University of Alberta and the Helmholtz Association.Interestingly, monazite from the diverse basement rocks display various kinds of pattern with respect to composition and origin. The great bulk of measured grains display variably declined chondrite-normalized LREE patterns virtually free of anomalies indicative for significant fluid-induced overprinting. We have rocks characterized by largely unzoned, chemically homogeneous grains. There are as well rocks containing nicely patchy-zoned grains showing a wide range in composition, in particular regarding the Th/LREE proportions. Here, maximum measured Th concentration amounted to 33 wt% ThO2. Incorporation of Th into the crystal structure is almost exclusively governed by the huttonite substitution reaction, i.e., Th^4+ + Si^4+ = REE^3+ + P^5+, as characteristic for this chemical type of granites (Förster 1998). The suite of rocks also included samples containing small-sized inclusions of Th-poor monazite in apatite, which formed in response to metamorphic, fluid-aided dissolution-reprecipitation processes (Harlov and Förster 2003, Harlov et al. 2005). Finally, we have a quartz monzonite containing Th-poor monazite in apatite together with matrix monazite of normal Th concentration, the origin if which is not yet fully resolved (cf. Foerster-2018-004_monazite-alberta-BSE images.pdf. presenting back-scattered electron images of monazite grains). In brief, the data set provides information on several aspects of formation and alteration of monazite in non-metamorphic and metamorphic granite.The data set published here contains the complete pile of data acquired for monazite-(Ce) and back-scattered electron (BSE) images of many of the probed grains. Chemical data are provided as Excel and machine-readable .csv files, which contain the information listed in Table 1 of the data description file. Column headers in red (only in the Excel version) indicate that the data and information provided in these columns is from Walsh (2013). “0.00” means that the concentrations of the respective elements were measured, but were below their limits of detection. Blank boxes in oxide concentrations columns indicate that the respective elements were not sought. The collection of BSE images is presented as pdf.file. The sample and grain numbers are given below each mineral image and are corresponding to the Sample No. and the Grain No. in the data table.The thesis of N. Walsh "Walsh, N.J. (2013) Geochemistry and geochronology of the Precambrian basement domains in the vicinity of Fort MacMurray, Alberta: a geothermal perspective. Master of Science thesis, Department of Earth and Atmospheric Sciences, University of Alberta, Canada" is not available online.
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 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.
This data set was collected in the frame of the ICDP drilling project DIVE (Drilling the Ivrea-Verbano ZonE) to determine the thermal properties of lower crustal lithologies and their variabilities. Two boreholes were drilled, the first 5071_1_B (in Ornavasso, final depth: 578.5 m) intersects the amphibolite-facies metasedimentary succession of the Ivrea-Verbano Zone, and the second borehole 5071_1_A (in Megolo, final depth: 909.5 m) is located within the mafic complex. Thermal properties were measured on fresh drill cores from the two DIVE boreholes and surface samples collected from nearby outcrops. The data set comprises thermal conductivity (TC), thermal diffusivity (TD), and specific heat capacity (Cp) measurements as well as measurements on concentrations of heat producing elements (HPE) Uranium (U), Thorium (Th), and Potassium (K) and the calculated radiogenic heat production (A).
The melting relations, phase compositions, and trace element partitioning behavior during metasediment partial melting were investigated by high pressure and temperature experiments (300 and 900 MPa, 750–950 °C). The here published dataset includes all geochemical analysis of experimental products and starting materials, Raman identification of experimental minerals, and quantification of experimental phase proportions. From this dataset, we provided new insights into the origin of rare-metal enriched granites.
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