权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Magma Differentiation processes and volatile contents in Shatsky Rise oceanic Plateau basalts: constraints from mineral, glass and melt inclusion compositions combined with experimental and thermodynamic modeling

沙茨基隆起海洋高原玄武岩中的岩浆分异过程和挥发物含量：矿物、玻璃和熔体包裹体成分的约束与实验和热力学模型相结合

基本信息

批准号：
180348309
负责人：
Professor Dr. Francois Holtz, Ph.D.
金额：
--
依托单位：
Institut für Mineralogie
依托单位国家：
德国
项目类别：
Infrastructure Priority Programmes
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/180348309?language=en
关键词：
Magma Differentiation processes volatile contents

项目摘要

Oceanic plateaus are giant volcanic constructs whose formation and existence is related to the enormous magma flux from mantle to lithosphere. These Large Igneous Provinces (LIPs) can be important indicators of fundamental processes of mantle convection and geodynamics, as well as major environmental changes and are crucial for advancing understanding of the whole Earth system. It is widely thought that oceanic plateaus arise from massive eruptions resulting from the arrival of a deep mantle plume head at the lithosphere. An alternative hypothesis invokes decompression melting of unusually fusible mantle beneath fast-spreading ridges. Shatsky Rise is a unique oceanic plateau, formed during the Late Jurassic and Early Cretaceous at a rapidly spreading triple junction, with characteristics that could be attributed to either model of formation. The goal of Integrated Oceanic Drilling Program Expedition 324 conducted in 2009 was to core the igneous rocks of Shatsky Rise and the sediments above to examine the age, physical volcanology, geochemistry, and tectonic evolution of the rise. In the proposed project we plan to contribute to the determination of magma storage conditions and to the simulation of differentiation processes in Shatsky Rise oceanic plateau. This information can be gained from (1) the study of recovered samples to determine chemical compositions of natural minerals, glasses and melt inclusions; (2) high pressure crystallization experiments and (3) thermodynamic modelling (COMAGMAT). The Shatsky Rise is also an ideal region to study pristine pre-eruptive volatile abundances in LIP basalts, due to the lack of contamination with continental lithosphere. The quantitative information on volatile budget, composition, oxygen fugacity, and volatile release in Shatsky Rise basaltic magmas will be obtained from a complementary approach combining analysis of natural glasses and melt inclusions, investigation of phase relationships at controlled oxygen fugacity and volatile activities. This is a prerequisite information to quantify the degassing of mantle plume derived melts and the possible climatic impact in Earth’s history.

大洋高原是一种巨大的火山构造，其形成和存在与地幔向岩石圈的巨大岩浆流有关。这些大火成岩省（LIPs）可以是地幔对流和地球动力学基本过程以及主要环境变化的重要指标，对于促进对整个地球系统的了解至关重要。人们普遍认为，海洋高原是由于深地幔柱头到达岩石圈而引起的大规模喷发而形成的。另一种假说认为，在快速扩张的海脊下，异常易熔的地幔减压熔融。沙茨基海隆是一个独特的海洋高原，形成于晚侏罗世和早白垩世，形成于一个快速扩张的三重连接点，其特征可以归因于两种形成模式。2009年进行的综合大洋钻探计划第324次考察的目标是对沙茨基隆起的火成岩和上面的沉积物进行岩心分析，以研究隆起的年龄、物理火山学、地球化学和构造演化。在拟议的项目中，我们计划有助于确定岩浆储存条件和模拟沙茨基海隆海洋高原的分异过程。这些信息可以从以下方面获得：（1）研究回收的样品，以确定天然矿物、玻璃和熔融包裹体的化学成分;（2）高压结晶实验;（3）热力学建模（COMAGMAT）。由于没有大陆岩石圈的污染，沙茨基隆起也是研究LIP玄武岩原始喷发前挥发分丰度的理想地区。挥发性的预算，组成，氧逸度，挥发性物质的释放，在沙茨基上升玄武岩岩浆的定量信息将获得从一个互补的方法结合分析天然玻璃和熔融包裹体，在控制氧逸度和挥发性活动的相关系的调查。这是一个先决条件的信息，以量化的地幔柱衍生熔体的脱气和可能的气候影响，在地球历史上。