Plagioclase picrites in the Kamchatsky Mys Peninsula,Eastern Kamchatka |
| |
| Authors: | D P Savelyev |
| |
| Institution: | 1. Institute of Volcanology and Seismology, Far East Branch, Russian Academy of Sciences, Petropavlovsk-Kamchatsky, 683006, Russia
|
| |
| Abstract: | The zone of serpentinite melange in the Kamchatsky Mys Peninsula was found to contain high-magnesium ultramafic volcanic rocks, viz., plagioclase picrite (oceanite) with a MgO concentration of 22.5–25.8%. We evaluated the petrochemical and geochemical characteristics of these rocks, as well as their mineral compositions. The olivine phenocrysts make up 50–60% of the rock volume; their composition (mostly 87–89 mol % Fo) and the composition of melt inclusions in them indicate their origin from a picritic melt with an additional cumulative enrichment in olivine. The geochemical parameters (Zr/Y = 3.1, Th/Yb = 0.14–0.18, Nb/Yb = 2.39–2.66, La(N)/Sm(N) = 1.0–1.1, La(N)/Yb(N) = 1.24–1.42) indicate an oceanic genesis of these rocks affected by a mantle plume. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
