Matches in SemOpenAlex for { <https://semopenalex.org/work/W4377138240> ?p ?o ?g. }
- W4377138240 abstract "Abstract Carbonatite intrusions host the world’s most important light rare earth element (LREE) deposits, and their formation generally requires extraordinary fertile sources, magmatic evolution, and hydrothermal events. However, carbonatitic magma evolution, particularly the role of fractional crystallization and contamination from silicate rocks in REE enrichment, remains enigmatic. The Maoniuping world-class REE deposit in southwestern China, is an ideal target to decipher magmatic evolution and related REE enrichment as it shows continuous textual evolution from medium- to coarse-grained calcite carbonatite (carbonatite I) at depth, to progressively pegmatoidal calcite carbonatite (carbonatite II) at shallow levels. In both types of calcite carbonatites, four generations of calcite can be classified according to petrographic and geochemical characteristics. Early-crystalizing calcite (Cal-I and Cal-II) are found in carbonatite I and exhibit equigranular and a polygonal mosaic textures, while late calcites (Cal-III and Cal-IV) in carbonatite II are large-size oikocrysts (>0.5 mm in length) with strain-induced undulatory extinction and bent twinning lamellae. All these generations of calcite yield similar, near-chondritic, Y/Ho ratios (26.6–28.1) and are inferred to be of magmatic origin. Remarkably, gradual enrichment of MgO, FeO and MnO from Cal-I to Cal-IV is coupled with a significant increase in REE contents (~800 to 2000 ppm), with LREE-rich and gentle-to-steep chondrite-normalized REE patterns ((La/Yb)N = 3.1–26.8 and (La/Sm)N = 0.9–3.9, respectively). Such significant REE enrichment is ascribed to protracted magma fractional crystallization with initial low degree of fractional crystallization (fraction of melt remining (F) = ~0.95) evolving to late stage (F = 0.5–0.6) by formation of abundant calcite cumulates. Differential LREE and HREE behavior during magma evolution largely depend on separation of phlogopite, amphibole, and clinopyroxene from the carbonatitic melt, which is indicated by progressively elevated (La/Yb)N ratios ranging from 3.1 to 26.8. The four generations of calcite have significantly different C and Sr isotopic compositions with δ13CV-PDB decreasing from −3.28 to −9.97‰ and 87Sr/86Sr increasing from 0.70613 to 0.70670. According to spatial relations and petrographic observations, the relative enrichment of δ13C and depletion in 87Sr/86Sr ratios of Cal-I and Cal-II show primary isotopic characteristics inherited from initial carbonatitic magma. By contrast, the variable Sr and C isotopic compositions of Cal-III and Cal-IV are interpreted as the results of contamination by components derived from silicate wall rocks and loss of CO2 by decarbonation reactions. To model such contamination processes, Raleigh volatilization and Monte Carlo simulation have been invoked and the model results reveal that carbonatitic melt-wall rock interaction requires 40% radiogenic Sr contamination from silicate rocks and 35% CO2 degassing from carbonatitic melt. Moreover, positive correlations between decreasing δ13C values and increasing REE contents, together with bastnäsite-(Ce) precipitation, indicate further REE accumulation during the contamination processes. In summary, alongside REE-rich magma sources, the extent of fractional crystallization and contamination during carbonatitic magma evolution are inferred to be important mechanisms in terms of REE enrichment and mineralization in carbonatite-related REE deposits worldwide." @default.
- W4377138240 created "2023-05-21" @default.
- W4377138240 creator A5005610147 @default.
- W4377138240 creator A5018286122 @default.
- W4377138240 creator A5021293751 @default.
- W4377138240 creator A5023180240 @default.
- W4377138240 creator A5067590457 @default.
- W4377138240 date "2023-05-19" @default.
- W4377138240 modified "2023-10-16" @default.
- W4377138240 title "Carbonatitic Magma Fractionation and Contamination Generate Rare Earth Element Enrichment and Mineralization in the Maoniuping Giant REE Deposit, SW China" @default.
- W4377138240 cites W1042275491 @default.
- W4377138240 cites W1196665483 @default.
- W4377138240 cites W1964532087 @default.
- W4377138240 cites W1968949026 @default.
- W4377138240 cites W1969859799 @default.
- W4377138240 cites W1970710130 @default.
- W4377138240 cites W1972106386 @default.
- W4377138240 cites W1973470655 @default.
- W4377138240 cites W1976571573 @default.
- W4377138240 cites W1979877704 @default.
- W4377138240 cites W1982491306 @default.
- W4377138240 cites W1982633669 @default.
- W4377138240 cites W1983028745 @default.
- W4377138240 cites W1986266401 @default.
- W4377138240 cites W1987734384 @default.
- W4377138240 cites W1988692830 @default.
- W4377138240 cites W1994014047 @default.
- W4377138240 cites W1998156597 @default.
- W4377138240 cites W1999708461 @default.
- W4377138240 cites W2010013343 @default.
- W4377138240 cites W2011561624 @default.
- W4377138240 cites W2012164920 @default.
- W4377138240 cites W2018869039 @default.
- W4377138240 cites W2019034794 @default.
- W4377138240 cites W2027732869 @default.
- W4377138240 cites W2030219984 @default.
- W4377138240 cites W2030612728 @default.
- W4377138240 cites W2034375483 @default.
- W4377138240 cites W2038279872 @default.
- W4377138240 cites W2041381933 @default.
- W4377138240 cites W2042486045 @default.
- W4377138240 cites W2043657251 @default.
- W4377138240 cites W2044078195 @default.
- W4377138240 cites W2046897746 @default.
- W4377138240 cites W2049943370 @default.
- W4377138240 cites W2051498333 @default.
- W4377138240 cites W2055780396 @default.
- W4377138240 cites W2060177679 @default.
- W4377138240 cites W2062658170 @default.
- W4377138240 cites W2067270209 @default.
- W4377138240 cites W2067831104 @default.
- W4377138240 cites W2071103381 @default.
- W4377138240 cites W2074041658 @default.
- W4377138240 cites W2075297859 @default.
- W4377138240 cites W2077101751 @default.
- W4377138240 cites W2081166664 @default.
- W4377138240 cites W2084638243 @default.
- W4377138240 cites W2085786036 @default.
- W4377138240 cites W2098032903 @default.
- W4377138240 cites W2099512276 @default.
- W4377138240 cites W2105648338 @default.
- W4377138240 cites W2107167500 @default.
- W4377138240 cites W2109817570 @default.
- W4377138240 cites W2115518283 @default.
- W4377138240 cites W2119028865 @default.
- W4377138240 cites W2123109488 @default.
- W4377138240 cites W2127236625 @default.
- W4377138240 cites W2133042542 @default.
- W4377138240 cites W2152391078 @default.
- W4377138240 cites W2163742713 @default.
- W4377138240 cites W2164468447 @default.
- W4377138240 cites W2167291234 @default.
- W4377138240 cites W2191589729 @default.
- W4377138240 cites W2201805341 @default.
- W4377138240 cites W2239284222 @default.
- W4377138240 cites W2324464168 @default.
- W4377138240 cites W2327214248 @default.
- W4377138240 cites W2330293686 @default.
- W4377138240 cites W2333705754 @default.
- W4377138240 cites W2408849960 @default.
- W4377138240 cites W2441695414 @default.
- W4377138240 cites W2466787799 @default.
- W4377138240 cites W2474271279 @default.
- W4377138240 cites W2474779303 @default.
- W4377138240 cites W2496236245 @default.
- W4377138240 cites W2505229739 @default.
- W4377138240 cites W2522303171 @default.
- W4377138240 cites W2568513730 @default.
- W4377138240 cites W2572776535 @default.
- W4377138240 cites W2573706076 @default.
- W4377138240 cites W2600861237 @default.
- W4377138240 cites W2620996655 @default.
- W4377138240 cites W2626432197 @default.
- W4377138240 cites W2767331878 @default.
- W4377138240 cites W2772349001 @default.
- W4377138240 cites W2773646395 @default.
- W4377138240 cites W2799744306 @default.
- W4377138240 cites W2883942823 @default.
- W4377138240 cites W2889530414 @default.
- W4377138240 cites W2891237507 @default.