1 CRYSTALLIZATION CONDITIONS OF TERPUK AREAL BASALTS
The study of the products of the Holocene areal volcanism of the northern part of the middle ridge of Kamchatka is interesting in that the Holocene volcanism of this zone cannot be unambiguously interpreted neither as the reflection of the conditions of the rear unit of the contemporary island arc n...
| Main Authors: | , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.485.7041 http://geo.web.ru/~ariskin/docs/papers/d03_135en.pdf |
| Summary: | The study of the products of the Holocene areal volcanism of the northern part of the middle ridge of Kamchatka is interesting in that the Holocene volcanism of this zone cannot be unambiguously interpreted neither as the reflection of the conditions of the rear unit of the contemporary island arc nor as the relict volcanism of earlier than the existed on Sredinny Ridge island arc.From this point of view, are most interesting the basaltic flows of the region of g.Terpuk, which are located to northwest from Shiveluch, northern active volcano of Kamchatka island arc.For determining the specific character of melts, evaluation of the compositions of the primordial melts and parameters of their existence were studied the large (50-100 mkm) melt inclusions in olivine phenocrysts (Fo82.7-85.2).Using melt inclusion compositions, the results of calculations in COMAGMAT software and data of spinel/melt equilibrium, are obtained the estimations of the intensive parameters at the crystallization of the magmas of the northern part of the middle ridge in central Kamchatka. Melt inclusions were reheated to the temperature 1250 C with the controlled oxygen fugacity at the level CCO buffer, they were sustained at this temperature during 6-10 min. and, then they were quenched. The studied grains of olivine had a composition Fo82.7-85.2. The inclusions, which exceed with the sizes of 25 mkm, were analyzed by EPMA (EDS) employing routine procedure [ e.g. |
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