RUI/Collaborative Research: Evaluating the Influence of Crustal Deformation on Episodic Magmatism: Southern Coast Mountains Batholith, British Columbia

RUI/合作研究：评估地壳变形对幕式岩浆作用的影响：不列颠哥伦比亚省南部海岸山脉基岩

• 批准号: 1347212
• 负责人: Margaret Rusmore
• 金额: $ 17.6万
• 依托单位: Occidental College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1347212&HistoricalAwards=false
• 关键词: RUI; Collaborative; Research; Evaluating; Influence

This project will evaluate processes responsible for the non-steady-state growth of continental crust in Cordilleran-type magmatic arcs. These batholiths develop as a result of subduction of oceanic lithosphere at convergent margins, but the processes that control the tempo of magma production are unclear; even in arcs where subduction is continuous, magmatism is strongly episodic (e.g. Sierra Nevada batholith, Peninsular Ranges batholith, Central Andes). Short periods (10-15 million years) of intense magmatism or 'flare-ups' may generate as much as 90% of total batholithic volumes, with little magmatism occurring during intervening lulls. Geochemical and isotopic signatures indicate that magmas produced during flare-ups incorporate more upper plate material than magmas formed during lulls. This pattern raises the question of whether continental growth by magmatic addition is controlled primarily by the behavior of the subducting oceanic plate or by the tectonics of the continental lithosphere at the plate margin. We are investigating this question through an integrated geologic, geochronological and geochemical study of the southern Coast Mountains Batholith in British Columbia. This project directly addresses a basic question in earth science: how do continents grow? In addition to the research goals of this project, this endeavor is enhancing the scientific education and training of students at four academic institutions recognized for the diversity of their student populations. Engagement of students in fieldwork, laboratory analysis, data interpretation and presentation of results are providing them with insights into all aspects of the science process and career options, and increase retention in STEM fields. Samples and datasets generated as a result of this project are being used to design problem sets and interpretive exercises for classes taught by the investigators. Data generated during this the course of this project is being added to NSF-funded databases, such as NAVDAT, for access by the larger community.

该项目将评估负责山脉型岩浆弧中大陆地壳非稳态生长的过程。这些沐浴石是由于在收敛边缘处俯冲而发展的，但是控制岩浆产生速度的过程尚不清楚。即使在俯冲是连续的弧线中，岩浆也是强烈的情节性（例如，内华达州的山利丝网，半岛山脉山脉，安第斯山脉中部）。短期（10-1500万年）强烈的岩浆或“爆发”可能会产生多达90％的沐浴石段石器时代的量，而在中间的停滞期间很少发生岩浆。地球化学和同位素特征表明，在爆炸过程中产生的岩浆比在lulls中形成的岩浆含有更多的上层板材。这种模式提出了一个问题，即岩浆添加的大陆生长是主要由俯冲式海洋板的行为或板缘大陆岩石圈的构造所控制的。 我们正在通过对不列颠哥伦比亚省南部海岸山浴的综合地质，地质学和地球化学研究来调查这个问题。该项目直接解决了地球科学中的一个基本问题：大陆如何发展？除了该项目的研究目标外，这项工作还加强了四家学术机构的科学教育和培训，以确认其学生人数的多样性。 学生参与现场工作，实验室分析，数据解释和结果的介绍，为他们提供了对科学过程和职业选择的各个方面的见解，并增加了STEM领域的保留率。 由于该项目而生成的样本和数据集用于设计问题集和研究人员教授的课程的解释性练习。 在此期间生成的数据正在添加到NSF资助的数据库中，例如NAVDAT，以供大型社区访问。