Based on the major, trace element, and isotope data of the Cenozoic basalts in the study area, it is indicated that the basalts in this region can be classified into three distinct magma systems: alka-li basalts, tholeiite basalts, and Nushan alkali basalts. The geochemical characteristics observed in the studied basalts indicate that the mantle source in this region might have experienced met-asomatic processes prior to partial melting, which could be linked to an ancient subduction pro-cess. Combining the geochemical characteristics in the studied basalts with previous research, we propose that the underlying mantle source in Anhui province may have undergone metaso-matism due to the carbonatitic melts. These melts are believed to have originated from car-bonated eclogite, derived from subducted Pacific slab materials present in the deeper mantle. According to the Sr-Nd isotope data, it is suggested that the mantle source in the Nushan region could be derived from a depleted asthenospheric mantle, while the basaltic composition in the Niugang area may be representative of the mantle's end components associated with the EM-I enriched mantle source present in this study area. Therefore, we propose that the Anhui basalts may have originated from the partial melting of a mantle source representing a mixing of two end-members: DMM (Depleted MORB Mantle) and EM-Ⅰ (Enriched Mantle 1). The Anhui basal-tic magmas may have originated from the partial melting of EM-Ⅰ, potentially influenced by upwelling asthenospheric mantle or asthenospheric diapirism processes. The mantle source in the study area experiences partial melting at 1-5%, 15%, and 1-10%, resulting in the formation of parent magmas for alkali basalt, tholeiitic basalt, and Nushan alkali basalt. Subsequently, the parent magmas experienced fractional crystallization processes, which included minerals like olivine, pyroxene, and plagioclase. This led to the formation of various types of basalt in the study area.

The Mazenod Lake region of the southern Great Bear Magmatic Zone (GBMZ) of the Northwest Territories, Canada comprises the north-central portion of the Faber volcano-plutonic belt. Mazenod geology is dominated by rhyodacite to basaltic-andesite ignimbrite sheets with interlayered volcaniclastic sedimentary rocks dominated by fine-grained laminated tuff sequences. Much of the intermediate to mafic nature of volcanic rocks is disguised by low-intensity but pervasive metasomatism. The region is affected by a series of coalescing magmatic-hydrothermal systems that host the Sue-Dianne magnetite-hematite IOCG deposit and several related showings including magnetite, skarn, and IOA styles of alteration ± mineralization. Exposed at surface are dominantly mid to upper levels of these systems, with underlying batholith, pluton and stocks exposed along the periphery, as well as locally within volcanic rocks associated with more intense alteration and mineralization. Widespread alteration includes potassic and sodic metasomatism, and silicification with structurally controlled giant quartz complexes. Localized tourmaline, skarn, magnetite-actinolite, and iron-oxides occur within structural breccias, and where most intense formed the Sue-Dianne Cu-Ag-Au diatreme-like breccia deposit. Magmatism, volcanism, hydrothermal alteration and mineralization formed during a negative tectonic inversion within the Wopmay Orogen. This generated a series of oblique offset rifted basins with continental style arc magmatism and extensional structures unique to GBMZ rifting. All significant hydrothermal centres in the Mazenod region occur along and at the intersections of crustal faults either unique to or put under tension during the GBMZ inversion.

We have studied quality characteristics, chemical, mineral and isotope composition of nephrite, diopsidite and rodingite of the Nyrdvomenshor deposit in the Polar Urals. We applied the visual petrographic and mineralogical studies, X-ray spectral fluorescence, ICP-MS analysis, scanning electron microscope with the dispersive microanalysis system, oxygen isotope composition was measured. According to its quality characteristics, the nephrite is substandard. Here, uvarovite, which forms idiomorphic grains, sometimes sheath-like, less often xenomorphic elongated, and substituting chromite are commonly encountered. The nephrite was formed due to both metamorphic and metasomatic processes. Serpentinite was replaced by diopsidite, which was then replaced by nephrite. Metamorphism intensified metasomatism of the serpentinite melange and provided a cryptocrystalline tangled-fibrous structure of the nephrite. Then metamorphism and metasomatism led to the formation of omphacite and cracking of the nephrite, which reduced its quality. As these processes progressed, contribution of crustal fluid increased.

A notable REE mineralization in Europe is associated with the Ditrău Alkaline Massif (DAM) in the Eastern Carpathians (Romania). It is an expression of the latest hydrothermal phase in the DAM and is found in the form of mineralized carbonate veins cross-cutting the complex in the NW (Jolotca region) and the SE (Belcina region) parts of the DAM. In the Belcina veins monazite-(Ce), xenotime-(Y), apatite, together with Fe-Mg-rich carbonate, thorite, thorogummite, gedrite and plagioclase are rock-forming. Three different textural and chemical types of the monazite-(Ce) and the xenotime-(Y) document a three-stage evolution. The relative phosphate age succession (from older to younger) thereby is xnt1 > xnt2 (>)+ mnz1 + Fe2O3 + Fe-gedrite > mnz2 + Fe-dolomite (+ plagioclase) > mnz3 + xnt3 + apatite. Phosphate chemistry shows that these crystallized from hydrothermal fluids, whereby each phosphate type follows a separate evolutionary path recommending growth from (at least) 3 independent and successive hydrothermal fluids. Chemistry and pathways within the DAM suggest that these hydrothermal fluids could be derived from a subsurface carbonatitic intrusion. Mnz1,2 and xnt1,2 ages are tightly cluster at 215.8 ± 0.7 Ma (Norian, Upper Triassic). The third-generation phosphate ages are younger, but associated with large analytical uncertainties and did not deliver geologically useful ages. The mean age of ca. 216 Ma is interpreted as timing the Belcina REE mineralization, what together with the fluid chemistry, supports a model of the presence of a late-stage, independent carbonatitic intrusion about 10 Ma after the main igneous activity (ca. 235 - 225 Ma) forming the DAM, synchronous with extension-related magmatism in the region.