Petrological processes of Moho formation

研究了莫霍面（地球内部最浅的全球性物理不连续面）的岩石学性质。研究结果对今后的大洋地幔钻探具有指导意义。在阿曼蛇绿岩中，层状辉长岩与地幔橄榄岩（主要为方辉橄榄岩）之间存在厚度为10 m ~ 1 km的Mono过渡带（MTZ）。MTZ主要由纯橄榄岩和伟氏岩组成，随着其厚度的增加而变得富Mg，显示出MORB/方辉橄榄岩反应产物的特征。在岛弧下方，MTZ通过堆积物的增生和水化作用改变其岩石学特征，并表现出强烈的非均质性和多样性。

Petrologic nature of Moho(Mohorovicic discontinuity), the shallowest of global physical discontinuities of the Earth's interior) has been investigated. Results of this study will guide the oceanic mantle drilling(Mohole) in the future. In the Oman ophiolite, a slice of Cretaceous oceanic lithosphere, the Mono transition zone(=MTZ), from 10 m to 1 km in thickness, is found between layered gabbro and the mantle peridotite(mainly harzburgite). The MTZ, mainly composed of dunites and wehrlites, becomes Mg-rich with an increase of its thickness, showing characteristics of a MORB/harzburgite reaction product. Beneath the island arc, the MTZ varies its petrologic characteristics through accretion of cumulates and hydration, and shows intense heterogeneities and varieties.