英语语法分析

The host rocks mainly are meta andesitic dacitic volcanic rocks.

容矿岩石主要是变质安山质-英安质火山岩类。

The volcanics are commonly andesitic in composition, but basaltic and rhyolitic volcanics are abundant in some areas.

火山岩的组成通常是安山岩，但在某些地区玄武岩质和流纹岩质也很丰富。

The Proterozoic volcanic rocks in Xiaogaizhou section is composed of rhyakkumulate, la-va breccia and lava with andesitic composition;

小盖州剖面元古宙火山岩具有安山岩岩石成分，由熔结角砾岩、熔岩角砾岩及熔岩组成。