Measurement of the Melting Curves of Mantle Materials and Their Geochemical Implications

9508016海因茨地幔物质的高温相平衡对地球内部深部的热结构有许多限制。 例如，铁镁硅酸盐钙钛矿的熔化曲线被认为是地球下地幔中的主要矿物，它对下地幔的温度有直接的实验限制，因为我们知道地幔是固体。 Fe的熔化曲线对内-外芯边界处的温度施加约束，只要可以考虑较轻的合金成分的存在。 来自不同激光加热实验室的主要矿物的熔化曲线是不一致的，需要理解这些差异，以便能够就正确的熔化温度达成共识。 在芝加哥大学开发的激光加热金刚石对顶砧单元中使用热分析技术的新实验将用于测量Fe-Mg硅酸盐钙钛矿、Fe-Mg硅酸盐钙钛矿和镁橄榄石的混合物、铁、镍、FeO和FeS对100 Gpa量级的压力的熔化曲线。 希望能够解决不同实验室之间在压力温度空间中熔化曲线位置的差异。 地幔矿物的熔融曲线可以用来对地幔的现状和演化进行地球化学约束。

9508016 Heinz The high-temperature phase equilibria of mantle materials place many constraints upon the thermal structure of the Earth's deep interior. For instance, the melting curve of Fe-Mg silicate perovskite, which is believed to be the major mineral in the Earth's lower mantle, places a direct experimental bound on the temperature in the lower mantle since we know that the mantle is solid. The melting curve of Fe places a constraint on the temperature at the inner-outer core boundary, provided one can take into account the presence of a lighter alloying component. Melting curves of the major minerals from various laser heating laboratories are discrepant, and the differences need to be understood to be able to aprive at a consensus for the correct melting temperatures. New experiments using the thermal analysis technique in the laser-heated diamond anvil cell, developed at the University of Chicago, will be used to measure the melting curves of Fe-Mg silicate perovskite, a mixture of Fe-Mg silicate perovskite and magnesiowustite, iron, nickel ,FeO, and FeS to pressures on the order of 100 Gpa. it is hoped that the discrepancies, in the location of the melting curve in pressure temperature space, between various laboratories can be resolved. The melting curves of mantle minerals can be used to place geochemical constraints on the current state and evolution of the Earth's mantle.