MORB数据挖掘:玄武岩判别图反思

MORB Data Mining:Reflection of Basalt Discrimination Diagram

板块构造学说推动了玄武岩理论的完善和进步,从20世纪70年代兴起的玄武岩构造环境判别方法成为学术界关注的热点,虽然现在逐渐降温了,但在国内仍然倍受青睐。大洋中脊玄武岩(MORB)是拥有数据最多、数据质量最好、研究得最详细的玄武岩类,是构建玄武岩理论的基石。本文利用Pet DB数据库资料(http://www.earthchem.org/petdb/search),对全球MORB数据进行了初步的挖掘,发现早先的玄武岩构造环境判别方法的理论、思路需要进一步的完善。早先研究认为,N-MORB是强烈亏损的。但本文研究却显示,MORB成分具有较宽的变化范围,包含了从MORB到OIB及IAB的组分,即部分MORB并不是亏损的,而是相对富集的。因此,玄武岩构造环境判别理论及方法有待进一步的完善。

The plate tectonic hypothesis enriched basalt theory. The basalt tectonic discrimination diagrams which raised in 1970s had been a hot topic for decades although it is much less popular as before, however, the method is still favored by some domestic scholars. Mid-Ocean Ridge Basalt （MORB） was the footstone for the basalt theory. This study presented an initial data mining based on the PetDB database （http：//www.earthchem.org/petdb/search） which showed that the past basalt tectonic discrimination diagrams should be updated. The previous studies considered that N-MORB is strong depleted in large ion lithophile elements, however, this study suggested that the N-MORBs have highly varied components. Therefore, the basalt tectonic environment discrimination method should be further improved and cautions must be taken in using of the discrimination diagrams.