洋壳的基本问题与人类的莫霍钻梦想  

Fundamental Questions of Ocean Crust and the Dream for Mohole

作　　者：周怀阳[1] 

机构地区：[1]同济大学海洋与地球科学学院,上海200092

出　　处：《地球科学进展》2017年第12期1245-1252,共8页Advances in Earth Science

摘　　要：一般认为,地球物理上的莫霍面是地幔和地壳的分界面。被海水覆盖的洋壳通常只有6~7km厚,相对于较厚的陆壳来说,洋壳不仅年轻得多,也活跃得多。然而,洋壳的地质结构以及莫霍面的地质意义到底是什么,至今仍是固体地球科学领域最大的悬疑之一。现有的结果表明,依据分布在大陆边缘的蛇绿岩套确定的Penrose模型基本不适用于慢速和超慢速扩张洋中脊的实际洋壳结构,对快速扩张洋中脊的适用性也有一定的疑问。解答洋壳结构及其莫霍面地质意义最有效的手段仍是大洋钻探。20世纪60年代初,试图挺进莫霍面的"莫霍钻"计划揭开了地球科学最伟大的大洋钻探计划的序幕。新世纪以来,随着各种研讨和计划的切实开展,人类真正实现莫霍钻梦想的日子似乎正在来临。Knowledge of ocean crust is one of bases to understand the deep and the surface of our planet. Since the definition of the Earth crust based on the geophysical discovery of Moho, marvelous efforts have been made to understand the geological significance of the Moho and the structure of the ocean crust. Up to date, it becomes clear that the Penrose model built up on ophiolite is unsuitable for the explanation of the ocean crust structure along slow and ultraslow spreading ridges, and probably also questionable for that of fast spreading ridges. The only effective way to solve the problem is to drill into the geophysical detected Moho and get samples. With the development of modern technology and more logic scientific strategy, that largely improved from the milestone Mohole projects car- ried out about half a century ago. The time to realize the Mohole dream seams coming.

关 键 词：洋壳结构 莫霍面 下洋壳 岩浆房 蛇绿岩套 

分 类 号：P756.5[天文地球—海洋科学]