Archean

The gold content of the Archean Taihua Group greenstone belt is lower than Clarke value.

太古宙太华群绿岩带金的丰度低于克拉克值。

Felsic gneiss is the most widely distributed rock type in Archean metamorphic complex areas.

长英质片麻岩是太古宙变质杂岩区最主要的岩石类型。

Such low levels of sulfate indicate that the archean atmosphere was virtually devoid of oxygen.

如此低的硫酸盐浓度，表示太古代大气中的氧气极为稀薄。

So far, many kinds of pattern for this type of deposit have been established except those in Archean terrain.

对该类型矿床的研究己经建立了多种形成模式，唯独高级变质组合地体中该类矿床的形成模式尚无成型的报导。

The nickel mineralization is contained in a layered basic massif surrounded and underlain by an archean gneiss complex.

此处镍矿化产于一层状基性岩块内，其四周和下面都为太古代片麻岩杂岩围绕。