Temperature of crystallization and evolution of the jumilla and Cancarix lamproites (SE Spain) as suggested by melt and solid inclusions in minerals
Salvioli-Mariani, Emma; Venturelli, Giampierο
European Journal of Mineralogy Volume 8 Number 5 (1996), p. 1027 - 1040
published: Oct 30, 1996
manuscript accepted: Apr 18, 1996
manuscript received: Sep 15, 1995
ArtNo. ESP147050805012, Price: 29.00 €
Abstract Rocks from Jumilla and Cancarix exhibit extreme compositions among the Spanish lamproites; the rocks of Jumilla have the highest MgO, P2O5, REE, Ba, Th and the lowest SiO2 contents, while the rocks from Cancarix have the highest SiO2 and K2O contents as well as high MgO, Cr, Ni, and Zr. Both groups of rocks are derived from peralkaline magmas. Microthermometric measurements on glass inclusions occurring in olivine, clinopyroxene, apatite, sanidine, K-richterite and phlogopite indicate temperatures of crystallization from about 1200°C to about 650°C at Jumilla and from about 1200°C to about 800°C at Cancarix. The chemical composition of the glass forming inclusions in olivine, clinopyroxene, apatite, sanidine, K-richterite and pseudobrookite as well as in late intercrystalline multiphase aggregates (Cancarix) indicates that the (Na + K)/Al ratio of the residual melts increased substantially during the cooling and crystallization of the magmas, reaching very high values. Solid inclusions of leucite and/or leucite accompanied by analcime within high temperature minerals, and rims of sanidine around analcime show that analcime is a secondary mineral after leucite.