玄武岩大地构造环境判别图评述

大地构造环境对玄武质岩浆成分有影响,但却不是主要的,更不是唯一的因素。源区物质成分、岩浆作用过程、地壳或岩石圈的混染及地球演化历史过程等是影响岩浆成分的主要因素。把玄武岩成分与大地构造环境紧密地联系在一起,并提出用玄武岩成分判别大地构造环境的作法,已经遇到了许多困难,这种方法用于变质玄武岩区问题更多。本文通过对目前常用的几种玄武岩成分-大地构造环境判别图的分析,认为如果不考虑其它因素,这类判别图对变质玄武岩几乎是不适用的。

A COMMENT ON THE BASALT TECTONIC SETTING DISCRIMINATION DIAGRAMS

Tectonic setting is neither important nor unique cause for controlling the basalt magma ingredients, though it can affect them. The sourses and evolution of magma,contidental contamination,the earth evolution and alternation to metabasalt are all important causes of controlling the basalt ingredients, though the one may be important and another secondary in different areas. A lot of difficulties might be encountered to discriminate tectonic setting with basalt chemistry. Using this method in the metabasalt area may meet much more difficulties. Several tectono-magmatic geochemical discrimination diagrams are discussed in this paper. It is proposed that these discrimination diagrams can not be used for metabasalt province, if other causes are not referred.