Matches in SemOpenAlex for { <https://semopenalex.org/work/W2024555437> ?p ?o ?g. }
Showing items 1 to 72 of
72
with 100 items per page.
- W2024555437 endingPage "182" @default.
- W2024555437 startingPage "182" @default.
- W2024555437 abstract "Morphologies, petrographic settings and carbon and nitrogen isotopic compositions of graphites in the Acapulco meteorite, the latter determined by secondary ionization mass spectrometry, are reported. Seven different graphite morphologies were recognized, the majority of which occur enclosed exclusively in kamacite. Individual graphite grains also rarely occur in the silicate matrix. Kamacite rims surrounding taenite cores of metal grains are separated from the Ni-rich metal cores by graphite veneers. These graphite veneers impeded or prevented Ni-Fe interdiffusion during cooling. In addition, matrix FeNi metal contains considerable amounts of phosphorous (≈ 700 ppm) and silicon (≈ 300 ppm) (Pack et al., 2005 in preparation) thus indicating that results of laboratory cooling experiments in the Fe-Ni binary system are inapplicable to Acapulco metals. Graphites of different morphologies display a range of carbon and nitrogen isotopic compositions, indicating a diversity of source regions before accretion in the Acapulco parent body. The isotopic compositions point to at least three isotopic reservoirs from which the graphites originated: (1) A reservoir with heavy carbon, represented by graphite in silicates (δ13C = 14.3 ± 2.4 ‰ and δ15N = −103.4 ± 10.9 ‰), (2) A reservoir with isotopically light carbon and nitrogen, characteristic for the metals. Its C- and N-isotopic compositions are probably preserved in the graphite exsolutions that are isotopically light in carbon and lightest in nitrogen (δ13C = −17 to −23 ‰ δ15N = −141 to −159 ‰). (3) A reservoir with an assumed isotopic composition (δ13C ∼ −5 ‰; δ15N ∼ −50 ‰). A detailed three-dimensional tomography in reflected light microscopy of the decorations of metal-troilite spherules in the cores of orthopyroxenes and olivines and metal-troilite veins was conducted to clarify their origin. Metal and troilite veins are present only near the fusion crust. Hence, these veins are not pristine to Acapulco parent body but resulted during passage of Acapulco in Earth’s atmosphere. A thorough search for symplectite-type silicate-troilite liquid quench textures was conducted to determine the extent of closed-system partial silicate melting in Acapulco.Metal-troilite spherules in orthopyroxenes and olivines are not randomly distributed but decorate ferromagnesian silicate restite cores, indicating that the metal-spherule decoration around restite silicates took place in a silicate partial melt. Graphite inclusions in these spherules have C- and N- isotopic compositions (δ13C = −2.9 ± 2.5 ‰ and δ15N = −101.2 ± 32 ‰) close to the average values of graphite in metals and in the silicate matrix, thus strongly suggesting that they originated from a mixture of graphite inclusions in metals and silicate matrix graphite during a closed system crystallization process subsequent to silicate-metal-sulfide partial melting. Troilite-orthopyroxene quench symplectite textures in orthopyroxene rims are clear evidence that silicate-sulfide partial melting took place in Acapulco. Due to petrographic heterogeneity on a centimeter scale, bulk REE abundances of individual samples or of individual minerals provide only limited information and the REE abundances alone are not entirely adequate to unravel the formational processes that prevailed in the acapulcoite-lodranite parent body. The present investigations demonstrate the complexity of the evolutionary stages of acapulcoites from accretion to parent body processes." @default.
- W2024555437 created "2016-06-24" @default.
- W2024555437 creator A5009554169 @default.
- W2024555437 creator A5030282028 @default.
- W2024555437 creator A5083229057 @default.
- W2024555437 date "1985-01-01" @default.
- W2024555437 modified "2023-09-23" @default.
- W2024555437 title "Dynamics of small gold crystals in real time by high resolution electron microscopy" @default.
- W2024555437 doi "https://doi.org/10.1016/0304-3991(85)90064-6" @default.
- W2024555437 hasPublicationYear "1985" @default.
- W2024555437 type Work @default.
- W2024555437 sameAs 2024555437 @default.
- W2024555437 citedByCount "2" @default.
- W2024555437 crossrefType "journal-article" @default.
- W2024555437 hasAuthorship W2024555437A5009554169 @default.
- W2024555437 hasAuthorship W2024555437A5030282028 @default.
- W2024555437 hasAuthorship W2024555437A5083229057 @default.
- W2024555437 hasConcept C104779481 @default.
- W2024555437 hasConcept C107872376 @default.
- W2024555437 hasConcept C113196181 @default.
- W2024555437 hasConcept C116862484 @default.
- W2024555437 hasConcept C121332964 @default.
- W2024555437 hasConcept C127313418 @default.
- W2024555437 hasConcept C130635790 @default.
- W2024555437 hasConcept C140205800 @default.
- W2024555437 hasConcept C159985019 @default.
- W2024555437 hasConcept C185592680 @default.
- W2024555437 hasConcept C191897082 @default.
- W2024555437 hasConcept C192562407 @default.
- W2024555437 hasConcept C199289684 @default.
- W2024555437 hasConcept C2776342828 @default.
- W2024555437 hasConcept C2779208318 @default.
- W2024555437 hasConcept C2779698641 @default.
- W2024555437 hasConcept C87355193 @default.
- W2024555437 hasConceptScore W2024555437C104779481 @default.
- W2024555437 hasConceptScore W2024555437C107872376 @default.
- W2024555437 hasConceptScore W2024555437C113196181 @default.
- W2024555437 hasConceptScore W2024555437C116862484 @default.
- W2024555437 hasConceptScore W2024555437C121332964 @default.
- W2024555437 hasConceptScore W2024555437C127313418 @default.
- W2024555437 hasConceptScore W2024555437C130635790 @default.
- W2024555437 hasConceptScore W2024555437C140205800 @default.
- W2024555437 hasConceptScore W2024555437C159985019 @default.
- W2024555437 hasConceptScore W2024555437C185592680 @default.
- W2024555437 hasConceptScore W2024555437C191897082 @default.
- W2024555437 hasConceptScore W2024555437C192562407 @default.
- W2024555437 hasConceptScore W2024555437C199289684 @default.
- W2024555437 hasConceptScore W2024555437C2776342828 @default.
- W2024555437 hasConceptScore W2024555437C2779208318 @default.
- W2024555437 hasConceptScore W2024555437C2779698641 @default.
- W2024555437 hasConceptScore W2024555437C87355193 @default.
- W2024555437 hasIssue "2" @default.
- W2024555437 hasLocation W20245554371 @default.
- W2024555437 hasOpenAccess W2024555437 @default.
- W2024555437 hasPrimaryLocation W20245554371 @default.
- W2024555437 hasRelatedWork W1017958604 @default.
- W2024555437 hasRelatedWork W1963553623 @default.
- W2024555437 hasRelatedWork W1968626576 @default.
- W2024555437 hasRelatedWork W1974360546 @default.
- W2024555437 hasRelatedWork W2094616265 @default.
- W2024555437 hasRelatedWork W2381182136 @default.
- W2024555437 hasRelatedWork W3034974222 @default.
- W2024555437 hasRelatedWork W3081203983 @default.
- W2024555437 hasRelatedWork W3168168554 @default.
- W2024555437 hasRelatedWork W1976786460 @default.
- W2024555437 hasVolume "17" @default.
- W2024555437 isParatext "false" @default.
- W2024555437 isRetracted "false" @default.
- W2024555437 magId "2024555437" @default.
- W2024555437 workType "article" @default.