The composional and dynamic evolution of a large-volume felsic system (Gran Canaria)

大体积长英质系统（大加那利岛）的成分和动态演化

• 批准号: 284373436
• 负责人: Professor Dr. Hans-Ulrich Schmincke
• 金额: --
• 依托单位: Forschungseinheit Magmatische und Hydrothermale Systeme
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/284373436?language=en
• 关键词: composional; dynamic; evolution; large; volume

Two main processes to explain the origin of highly evolved volcanic rocks on oceanic islands (rhyolites to phonolites) have been proposed for over 100 years: (1) crystal fractionation of basaltic magmas and (2) partial melting of crustal rocks of basaltic derivation and (3) a combination of these mechanisms. Gran Canaria, the paradigmatic endmember of oceanic bimodal basaltic - evolved volcanism, has erupted >100 km3 of practically exclusively felsic volcanics for >6 million years, represents a unique case history for documenting boundary conditions for the generation of a broad spectrum of evolved magmas. Rock units from 3 targets representing the very early, an intermediate and late stage of felsic volcanism will be subjected to thorough lithological, compositional/petrological and temporal analysis to provide a solid database on which to build a broader analytical strategy as well as a synthesis of the results of several decades of work on individual volcanic units.

100多年来，人们提出了两个主要过程来解释大洋岛屿上高度演化的火山岩（流纹岩到响岩）的起源：（1）玄武岩浆的晶体分异和（2）玄武岩衍生的地壳岩石的部分熔融和（ 3）这些机制的组合。大加那利岛是海洋双峰玄武岩演化火山活动的典型端元，在超过 600 万年的时间里喷发了超过 100 平方公里的几乎完全是长英质火山岩，代表了记录广泛演化岩浆生成的边界条件的独特历史案例。来自代表长英质火山活动极早期、中期和晚期阶段的 3 个目标的岩石单元将接受彻底的岩性、成分/岩石学和时间分析，以提供可靠的数据库，在此基础上建立更广泛的分析策略以及综合几十年来对各个火山单元的研究成果。