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

大陆裂谷火山的实验岩石学和地球化学：演化的碱性岩浆的岩石成因

• 批准号: 9316197
• 负责人: Richard Wendlandt
• 金额: $ 13.4万
• 依托单位: Colorado School of Mines
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-06-01 至 1998-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316197&HistoricalAwards=false
• 关键词: Experimental; Petrology; Geochemistry; Continental; Rift

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.

9316197 Wendlandt拟议的研究涉及碱性玄武岩的实验研究，以前的地球化学和反向方法实验研究表明，是大量的，裂谷相关的，火山发生的父母。 将利用高压高温前向熔融实验来确定地壳内形成这些熔岩所必需的过程和物理化学条件。 具体实验目标是：（1）确定液体的下降线（2）确定在中地壳到上地幔压力和温度范围内，碱性玄武岩成分的平衡部分熔融或结晶形成的熔体的分馏路径;（3）表征残余相组合（堆积岩）;（4）比较碱性玄武岩熔融实验的相组成与在液相线条件下记录的中间组成熔岩的相组成。 拟议的实验和分析研究的结果将为评估地壳条件下熔体演变的多压路径提供依据，并能够为大陆裂谷结构和演变以及地壳参与裂谷过程的大陆模型开发综合模型。