Kirschsteinite (mainly CaFeSiO4), in association with forsterite-fayalite solid solutions, melilite, clinopyroxene, leucite, nepheline and several minor phases, is reported for the first time in the 290 ka Capo di Bove melilite-leucitite lava flow of the Alban Hills volcanic complex (Italy). Kirschsteinite appears very late in the crystallization sequence, as indicated by textural and chemical evidence (Mg# ≈ 25). It shows significant solid solution towards fayalite, and is found with groundmass phases indicating a relatively low-temperature melt composition more silica-undersaturated than phonolite (i.e. devoid of alkali feldspar). This clearly points to the very silica-undersaturated nature of almost all the Alban Hills volcanic rocks.
Kirschsteinite in the Capo Bove melilite leucitite (cecilite), Alban Hills, Italy / L. MELLUSO; S. CONTICELLI; R. DE’ GENNARO. - In: MINERALOGICAL MAGAZINE. - ISSN 0026-461X. - STAMPA. - 74:(2010), pp. 859-874. [10.1180/minmag.2010.074.5.859]
Kirschsteinite in the Capo Bove melilite leucitite (cecilite), Alban Hills, Italy
CONTICELLI, SANDRO;
2010
Abstract
Kirschsteinite (mainly CaFeSiO4), in association with forsterite-fayalite solid solutions, melilite, clinopyroxene, leucite, nepheline and several minor phases, is reported for the first time in the 290 ka Capo di Bove melilite-leucitite lava flow of the Alban Hills volcanic complex (Italy). Kirschsteinite appears very late in the crystallization sequence, as indicated by textural and chemical evidence (Mg# ≈ 25). It shows significant solid solution towards fayalite, and is found with groundmass phases indicating a relatively low-temperature melt composition more silica-undersaturated than phonolite (i.e. devoid of alkali feldspar). This clearly points to the very silica-undersaturated nature of almost all the Alban Hills volcanic rocks.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.