Collaborative Research: Arc Volcanism in Kamchatka, U.S.S.R., through both Partial Melting of the Mantle Wedge and Subducted Slab: A Geochemical and Tectonic Approach

合作研究：苏联堪察加半岛的弧火山作用，通过地幔楔和俯冲板的部分熔融：地球化学和构造方法

• 批准号: 9103062
• 负责人: Mark Drummond
• 金额: $ 5.17万
• 依托单位: University of Alabama at Birmingham
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-01 至 1994-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9103062&HistoricalAwards=false
• 关键词: Collaborative; Research; Arc; Volcanism; Kamchatka

Kamchatka arc provides a unique opportunity to test the hypothesis that adakites are derived from the melting of subducted oceanic crust and/or lower continental crust. The southern section of the Kamchatka arc consists of active and inactive volcanoes with mantle derived magmas. The northern section (north of the Bering F.Z.) volcanism includes both normal and adakite geochemistries. The adakites are associated only with the subduction of the young crust in the Komandorsky basin. The first objective will be to compare and contrast "normal" arc volcanism in the southern section of the arc with the adakite volcanism found in the northern section. There are several xenoliths found among the adakites including granulites, cortlandites, amphibolites, hornblendites, pyroxenites, and gabbros. The large range of xenoliths in the samples may enable the PIs to document the source of the adakites. They will use a microprobe and an ion microprobe to document the geochemical signatures and P-T conditions of the xenoliths which should make it possible to choose between the lower crust or subducted slab as the source of the adakites.

堪察加岛弧提供了一个独特的机会来检验这一假设 埃达克岩来自俯冲洋壳的熔融 地壳和/或下大陆地壳。 堪察加岛弧的南段由活跃的 有地幔岩浆的不活跃火山。 北方 段（白令自由区以北）火山活动包括正常的 埃达克岩地球化学 埃达克岩只与 科曼多尔斯基盆地年轻地壳的俯冲。 的 第一个目标是比较和对比“正常”弧线 火山作用在弧的南段与埃达克岩 在北方发现的火山活动。 在埃达克岩中发现了几种捕虏体， 麻粒岩，cortlandite，斜长角闪岩，角闪石，辉石， 和辉长岩 样品中捕虏体种类繁多， 让私家侦探记录埃达克岩的来源 他们将 使用微探针和离子微探针记录 捕虏体的地球化学特征和P-T条件， 应该可以在下地壳和 俯冲板片是埃达克岩的源区。