Experimental Petrology and Geochemistry of Continental Rift Volcanics: Intermediate Composition Lavas

本项目旨在研究其成因和构造 中间成分洪水喷发意义 与大陆裂谷有关 化学和辐射测量 对大约10个天然洪泛响岩进行同位素分析， 粗面岩熔岩将被用来限制可能的来源 储层和这些熔岩的演化。 熔化 对该套件中的样本进行的实验将用于检查 过程和P，T。和必要的组成条件 这些熔岩的起源 可能的矿源， 多压和多温结晶序列， 挥发物在部分熔化和物质传输中的作用 鉴定 成分简化的补充研究 模拟系统将有助于解释相位关系 并将结果外推到不同的岩浆成分。 如果合适的话，前向方法研究将测试岩石成因 从逆向实验中得出的模型。 综合实验和分析的结果表明， 这种方法与理解传热和传质有关 从地幔到地壳，确定参与 地壳在裂谷岩浆活动，并制定地球物理模型， 裂谷演化与构造

This project is to investigate the origins and tectonic significance of intermediate composition flood eruptives that re associated with continental rifts. Chemical and radiometric isotopic analyses of approximately 10 natural flood phonolite and trachyte lavas will be used to constrain possible source reservoir(s) and the evolution of these lavas. Melting experiments on samples from this suite will be used to examine the processes and the P, T. and composition conditions necessary for the genesis of these lavas. Possible source mineralogies, polybaric and polythermal crystallization sequences, and the role of volatiles in partial melting and mass transport will be identified. Complementary studies of compositionally simplified analog systems will facilitate interpretation of phase relations and extrapolation of results to different magma compositions. Forward approach studies, if appropriate, will test petrogenetic models that result from the inverse experiments. The result of this integrated experimental and analytical approach are relevant to understanding heat and mass transfer from mantle to crust during rifting, identifying the involvement of crust in rift magmatism, and developing geophysical models for rift evolution and structure.