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Abstract:
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.
