Experimental Study of Pyroxenite Partial Melting in the MORBSource Region

摘要：洋中脊玄武岩在洋中脊上一个位置和沿洋中脊的化学差异已经被注意了一段时间。人们提出了各种熔融、地幔非均质性和熔融通过地幔迁移的模型来解释这些差异。PI假设，这种差异是由于地幔中存在的辉石岩脉优先熔化，并且在比大部分地幔更深的深度熔化。因此，这少量的物质（约占地幔的5%）可能贡献了到达某些地方表面的20%以上的融水，从而造成了玄武岩中所见的化学差异。PI计划在地幔条件下融化辉石岩，以确定可能对海脊玄武岩有贡献的熔体成分。

9706526 Hirschmann Summary: The chemical differences in mid-ocean ridge basalts at one location on a ridge and along a ridge have been noted for some time. Various models of melting, mantle heterogeneity, melt migration through the mantle have been proposed to explain these differences. The PI hypothesizes that the differences are due to the presence pyroxenite veins in the mantle that melt preferentially and at greater depth than the bulk of the mantle. Thus this small amount of material (about 5% of the mantle) could contribute more than 20% of the melt that reaches the surface in some places, thus causing the chemical differences seen in the basalts. The PI plans to melt pyroxenites under mantle conditions to determine the compositions of melts that might contribute to the ocean ridge basalts.