Evolution of Intraplate Magmas: An Experimental Approach

[902931 . lindsley]这项研究的目的是：(1)验证这样一个假设，即与羽流和裂陷有关的各种岩浆套件可能来自一个共同的母岩浆（尽管不是原始的）；(2)确定受不同压力和氧化态控制的岩浆分馏趋势变化；(3)评估与斜长岩相关的熔体之间的可能关系；(4)测试中压下碳的溶解度是否能引起某些岩浆的强富铁。所使用的实验技术是在活塞-气缸压力装置中进行的分数结晶实验，具有各种压力，样品容器和强制氧度。实验产品使用岩石显微镜，x射线衍射和电子探针微量分析仪进行检查。当矿物与熔体发生反应时，或晶体的比例超过50%时，将合成一种新的体成分，与先前实验中的熔体成分相对应。该程序允许在温度降低时评估分馏结晶，但在每个实验中保持相对较高的熔体比例，这对微探针分析和达到平衡是有用的。

9902931LindsleyThe goal of this research is to (1) test the hypothesisthat a variety of magma suites associated with plumes and rifting might bedescended from a common parental (although not primitive) magma; (2)determine variations in magmatic fractionation trends that are controlledby different pressures and oxidation states; (3) assess possible relationsbetween melts associated with anorthosites; and (4) test whether thesolubility of carbon at moderate pressures can cause strong iron-enrichmentin some magmas. The experimental technique used is fractionalcrystallization experiments performed in piston-cylinder pressureapparatus, with a variety of pressures, sample containers, and imposedoxygen fugacities. Experimental products are examined using thepetrographic microscope, x-ray diffraction, and the electron probemicroanalyser. When reactions between minerals and melt occur, or when theproportion of crystals exceeds 50%, a new bulk composition will besynthesized, corresponding to the composition of the melt in the previousexperiment. This procedure permits evaluation of fractionalcrystallization as temperature is lowered, yet maintains a relatively highproportion of melt in each experiment, which is useful for microprobeanalysis and attainment of equilibrium.