Experimental Petrology and Geochemistry of Continental Rift Volcanics: Petrogenesis of Evolved, Alkaline Magmas

9316197温德兰特拟议的研究涉及对碱性玄武岩的实验研究，以前的地球化学和反向实验研究表明，这是大量与裂谷相关的火山产状的母体。将使用高压和高温正向熔融实验来表征这些熔岩形成所必需的地壳内的过程和物理和化学条件。具体实验目标是：(1)确定中地壳至上地幔压力和温度范围内由碱性玄武岩成分的平衡部分熔融或结晶产生的熔体的液线下降线(分馏路径)；(2)确定在这些压力和温度条件下存在的矿物相的组成；(3)表征残余相组合(累积岩性)；以及(4)将碱性玄武岩熔融实验的相组成与在液态线条件下记录的中间成分熔岩的相组成进行比较。拟议的实验和分析研究结果将为评估地壳条件下熔体演化的多重波路径提供基础，并使大陆裂谷结构和演化的大陆模型以及地壳参与裂谷过程的综合模型得以发展。

9316197 Wendlandt The proposed research involves experimental investigations of alkali basalts, demonstrated by previous geochemical and inverse-approach experimental studies to be parental to voluminous, rift-associated, volcanic occurrences. High pressure and temperature forward-approach melting experiments will be used to characterize the processes and the physical and chemical conditions within the crust necessary for the genesis of these lavas. Specific experimental objectives are: (1) to determine liquid lines of descent (fractionation paths) for melts derived by equilibrium partial melting or crystallization of alkali basalt compositions for a range of mid-crustal to upper mantle pressures and temperatures; (2) to determine the compositions of mineral phases present at these pressure and temperature conditions; (3) to characterize residual phase assemblages (cumulate lithologies); and (4) to compare compositions of phases from alkali basalt melting experiments with those documented at liquidus conditions for intermediate composition lavas. The results of the proposed experimental and analytical studies will provide a basis for evaluating polybaric paths for melt evolution at crustal conditions and enable development of integrated models for continental models for continental rift structure and evolution and for the involvement of crust in rifting processes.