抄録
<jats:title>Summary</jats:title><jats:p>A 250 µm olivine crystal in Sharps contains 1 to 5 µm insets identified by microprobe analysis as ferroan monticellite, spinel, and fassaite with average compositions: olivine (host), (Fe<jats:sub>0·44</jats:sub>Mg<jats:sub>1·51</jats:sub>Ca<jats:sub>0·05</jats:sub>) (Si<jats:sub>0·99</jats:sub>Al<jats:sub>0·01</jats:sub>)O<jats:sub>4</jats:sub>; ferroan monticellite, (Ca<jats:sub>0·89</jats:sub>Fe<jats:sub>0·41</jats:sub>Mg<jats:sub>0·66</jats:sub>) (Si<jats:sub>1·00</jats:sub>Al<jats:sub>0·02</jats:sub>)O<jats:sub>4</jats:sub>; spinel, (Fe<jats:sub>0·41</jats:sub>Mg<jats:sub>0·59</jats:sub>)(Fe<jats:sub>0·06</jats:sub><jats:sup>3+</jats:sup>Cr<jats:sub>0·23</jats:sub>Al<jats:sub>1·69</jats:sub>Si<jats:sub>0·01</jats:sub>Ti<jats:sub>0·01</jats:sub>)O<jats:sub>4</jats:sub>; and fassaite, Ca<jats:sub>0.96</jats:sub>(Fe<jats:sub>0·01</jats:sub>Mg<jats:sub>0·59)</jats:sub>(Al<jats:sub>0·18</jats:sub>Ti<jats:sub>0·07</jats:sub>Fe<jats:sub>0·16</jats:sub><jats:sup>3+</jats:sup>)(Si<jats:sub>1·53</jats:sub>Al<jats:sub>0·47</jats:sub>)O<jats:sub>6</jats:sub>. Textural and experimental data suggest early crystallization of spinel from a calcic olivine melt, exsolution of ferroan monticellite from the host olivine, and reaction of spinel and ferroan monticellite to form fassaite. The severe depletion of alkalies and silica in this crystal suggests it is a residue from vapour fractionation.</jats:p>
収録刊行物
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- Mineralogical Magazine
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Mineralogical Magazine 38 (296), 451-458, 1971-12
Mineralogical Society
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詳細情報
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- CRID
- 1361981470813161600
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- NII論文ID
- 30022408275
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- ISSN
- 14718022
- 0026461X
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- データソース種別
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- Crossref
- CiNii Articles