Quelques précisions sur la constitution minéralogique de la néphélinite à olivine et mélilite d'Essey-la-Côte (Meurthe-et-Moselle)

1973; Wentworth Press; Volume: 96; Issue: 4 Linguagem: Inglês

10.3406/bulmi.1973.6832

ISSN

2772-9788

Autores

Danielle Velde, Jean Thiébaut,

Tópico(s)

Crystal Structures and Properties

Resumo

An olivine melilite nephelinite outcrops near Essey-la-Côte. The chemical composition of its major constituants has been determined using the electron microprobe with the following results : olivine varies little, from Fo₈₄ to Fo₈₇. Clinopyroxene is zoned, the outer rims being enriched in aluminium and titanium. Melilite is sodium-rich, with a composition Ak₅₈-Na melilite₁₉. Nepheline is potassium rich, its structural formula being close to Na₃KAl₄Si₄O₁₆.

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