Titlebook: Carbonatite Volcanism; Oldoinyo Lengai and Keith Bell,J?rg Keller Book 1995 Springer-Verlag Berlin Heidelberg 1995 chemistry.geochemistry.

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IAVCEI Proceedings in Volcanologyhttp://image.papertrans.cn/c/image/221681.jpg

morale

MAIM

Nonlinear Dielectric Susceptibilitieshe pioneering work by J.B. Dawson on the natrocarbonatite lavas of the 1960–61 eruption, this volcano has held an understandable fascination for volcanologists, geochemists and petrologists, and has resulted in considerable debate as to whether the natrocarbonatite is a primary or derivative melt.

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Nonlinear Dielectric Susceptibilities extinct, crater. Following a period of erosion, black nephelinitic ashes were erupted starting about 1250 a from a new northern crater, which has been the site of subsequent activity; altered natrocarbonatite lava blocks occur in these tuffs. Natrocarbonatite lava was first recorded in the summit a

BILK

土坯

Nonlinear Dielectric Susceptibilitiesstem. Observations of bubbles bursting in a lava lake, and sudden changes in magma level and vesicularity at active vents are consistent with the degassing model developed by Jaupart and Vergniolle (1988, 1989), and suggest that the shallow plumbing system comprises several small (<10-m radius) cham

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occult

Nonlinear Dielectric Susceptibilitiese data, together with trace element data for the phenocryst phases nyerereite and gregoryite and for a related peralkaline nephe-linite, provide the basis for discussing petrogenetic hypotheses related to alkalic carbonatites. Natrocarbonatites are characterized, compared to the more common calcioca

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6.1.1.3 Crystal-name abbreviations,elation, and closely follow the East African Carbonatite Line (EACL). The .Nd/.Nd ratios of the lavas range from 0.51249 to 0.51269, those of plutonic blocks from 0.51174 to 0.51270. The .Sr/.Sr of the lavas range from 0.70414 to 0.70512; plutonic blocks range from 0.70378 to 0.70861. The nephelinit