Matches in SemOpenAlex for { <https://semopenalex.org/work/W1974324769> ?p ?o ?g. }
Showing items 1 to 89 of
89
with 100 items per page.
- W1974324769 endingPage "994" @default.
- W1974324769 startingPage "975" @default.
- W1974324769 abstract "The present work summarizes a detailed investigation of perovskite from a representative collection of kimberlites, including samples from over forty localities worldwide. The most common modes of occurrence of perovskite in archetypal kimberlites are discrete crystals set in a serpentine–calcite mesostasis, and reaction-induced rims on earlier-crystallized oxide minerals (typically ferroan geikielite or magnesian ilmenite). Perovskite precipitates later than macrocrystal spinel (aluminous magnesian chromite), and nearly simultaneously with “reaction” Fe-rich spinel ( sensu stricto ), and groundmass spinels belonging to the magnesian ulvospinel – magnetite series. In most cases, perovskite crystallization ceases prior to the resorption of groundmass spinels and formation of the atoll rim. During the final evolutionary stages, perovskite commonly becomes unstable and reacts with a CO 2 - rich fluid. Alteration of perovskite in kimberlites involves resorption, cation leaching and replacement by late-stage minerals, typically TiO 2 , ilmenite, titanite and calcite. Replacement reactions are believed to take place at temperatures below 350°C, P a (Mg 2+ ) values. Perovskite from kimberlites approaches the ideal formula CaTiO 3 , and normally contains less than 7 mol.% of other end-members, primarily lueshite (NaNbO 3 ), loparite (Na 0.5 Ce 0.5 TiO 3 ), and CeFeO 3 . Evolutionary trends exhibited by perovskite from most localities are relatively insignificant and typically involve a decrease in REE and Th contents toward the rim (normal pattern of zonation). A reversed pattern is much less common, and probably results from re-equilibration of perovskite with a kimberlitic magma modified by assimilation or contamination processes. Oscillatory zonation on a fine scale is comparatively uncommon, and involves subtle variations in LREE , Th, Nb and Fe. Relatively high levels of LREE , Th and Nb observed in perovskite from some occurrences (Lac de Gras and Kirkland Lake in Canada, Obnazhennaya in Yakutia) probably result from inherent enrichment of the host kimberlites in “incompatible” elements. In some cases (Benfontein in South Africa), differentiation processes may have contributed to the accumulation of “incompatible” elements in perovskite." @default.
- W1974324769 created "2016-06-24" @default.
- W1974324769 creator A5081333225 @default.
- W1974324769 creator A5086932226 @default.
- W1974324769 date "2000-08-01" @default.
- W1974324769 modified "2023-10-16" @default.
- W1974324769 title "OCCURRENCE, ALTERATION PATTERNS AND COMPOSITIONAL VARIATION OF PEROVSKITE IN KIMBERLITES" @default.
- W1974324769 cites W1963238787 @default.
- W1974324769 cites W1969333093 @default.
- W1974324769 cites W2037085475 @default.
- W1974324769 cites W2052114181 @default.
- W1974324769 cites W2074256354 @default.
- W1974324769 cites W2074986581 @default.
- W1974324769 cites W2087343476 @default.
- W1974324769 cites W2145097655 @default.
- W1974324769 cites W2182095308 @default.
- W1974324769 cites W2182925616 @default.
- W1974324769 cites W2226922233 @default.
- W1974324769 cites W2297438515 @default.
- W1974324769 cites W2464752438 @default.
- W1974324769 cites W2469593127 @default.
- W1974324769 cites W2484699437 @default.
- W1974324769 cites W2512724726 @default.
- W1974324769 cites W2596643234 @default.
- W1974324769 cites W2597875292 @default.
- W1974324769 cites W2600814727 @default.
- W1974324769 cites W2965846044 @default.
- W1974324769 cites W594116056 @default.
- W1974324769 cites W618488932 @default.
- W1974324769 cites W623439916 @default.
- W1974324769 doi "https://doi.org/10.2113/gscanmin.38.4.975" @default.
- W1974324769 hasPublicationYear "2000" @default.
- W1974324769 type Work @default.
- W1974324769 sameAs 1974324769 @default.
- W1974324769 citedByCount "80" @default.
- W1974324769 countsByYear W19743247692012 @default.
- W1974324769 countsByYear W19743247692013 @default.
- W1974324769 countsByYear W19743247692014 @default.
- W1974324769 countsByYear W19743247692015 @default.
- W1974324769 countsByYear W19743247692016 @default.
- W1974324769 countsByYear W19743247692017 @default.
- W1974324769 countsByYear W19743247692018 @default.
- W1974324769 countsByYear W19743247692019 @default.
- W1974324769 countsByYear W19743247692020 @default.
- W1974324769 countsByYear W19743247692021 @default.
- W1974324769 countsByYear W19743247692022 @default.
- W1974324769 countsByYear W19743247692023 @default.
- W1974324769 crossrefType "journal-article" @default.
- W1974324769 hasAuthorship W1974324769A5081333225 @default.
- W1974324769 hasAuthorship W1974324769A5086932226 @default.
- W1974324769 hasConcept C121332964 @default.
- W1974324769 hasConcept C127313418 @default.
- W1974324769 hasConcept C17409809 @default.
- W1974324769 hasConcept C183282558 @default.
- W1974324769 hasConcept C199289684 @default.
- W1974324769 hasConcept C2778334786 @default.
- W1974324769 hasConcept C44870925 @default.
- W1974324769 hasConcept C5900021 @default.
- W1974324769 hasConcept C67236022 @default.
- W1974324769 hasConceptScore W1974324769C121332964 @default.
- W1974324769 hasConceptScore W1974324769C127313418 @default.
- W1974324769 hasConceptScore W1974324769C17409809 @default.
- W1974324769 hasConceptScore W1974324769C183282558 @default.
- W1974324769 hasConceptScore W1974324769C199289684 @default.
- W1974324769 hasConceptScore W1974324769C2778334786 @default.
- W1974324769 hasConceptScore W1974324769C44870925 @default.
- W1974324769 hasConceptScore W1974324769C5900021 @default.
- W1974324769 hasConceptScore W1974324769C67236022 @default.
- W1974324769 hasIssue "4" @default.
- W1974324769 hasLocation W19743247691 @default.
- W1974324769 hasOpenAccess W1974324769 @default.
- W1974324769 hasPrimaryLocation W19743247691 @default.
- W1974324769 hasRelatedWork W1967557881 @default.
- W1974324769 hasRelatedWork W2014431104 @default.
- W1974324769 hasRelatedWork W2067421025 @default.
- W1974324769 hasRelatedWork W2067737382 @default.
- W1974324769 hasRelatedWork W2166902260 @default.
- W1974324769 hasRelatedWork W2349947565 @default.
- W1974324769 hasRelatedWork W2350862504 @default.
- W1974324769 hasRelatedWork W2358025071 @default.
- W1974324769 hasRelatedWork W2380934447 @default.
- W1974324769 hasRelatedWork W2925533717 @default.
- W1974324769 hasVolume "38" @default.
- W1974324769 isParatext "false" @default.
- W1974324769 isRetracted "false" @default.
- W1974324769 magId "1974324769" @default.
- W1974324769 workType "article" @default.