Crustal Evolution of North Luzon; Transition from Island Arcs to Micro-Continent

北吕宋岛的地壳演化；

• 批准号: 9018050
• 负责人: James Hawkins
• 金额: $ 7.49万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 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: 1991-02-15 至 1994-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9018050&HistoricalAwards=false
• 关键词: Crustal; Evolution; North; Luzon; Transition

The principal investigator will map, sample, and make a mineralogic-petrologic-geochemical-isotopic study of selected plutonic and volcanic rocks in north Luzon, Philippines. The purpose is to determine the chemical and isotopic compositions of four distinct increments of crustal rocks that have led to the progressive transformation from basaltic island arc crust to more highly evolved crust. The investigation will address the question of whether the Luzon arc systems formed largely from melts of the mantle wedge above subduction zones, followed by modification via assimilation zone-refining of the arc crust, plus fractional crystallization, resulting later in the production of more granitic compositions. This area offers a unique opportunity for geologists to trace the early stages of crustal evolution of a microcontinent.

首席研究员将对菲律宾吕宋岛北部选定的深成岩和火山岩进行测绘、取样和矿物学-岩石学-地球化学-同位素研究。目的是确定四种不同的地壳岩石增量的化学和同位素组成，这些增量导致了玄武岩岛弧地壳向更高度演化的地壳的逐步转变。该研究将探讨吕宋弧系是否主要由俯冲带上方的地幔楔体熔体形成，然后经过同化带-弧壳精炼的改造，再加上分块结晶，导致后来产生更多的花岗岩成分。这个地区为地质学家提供了一个独特的机会来追溯微大陆的早期地壳演化阶段。