洋脊火山

岛弧和洋中脊火山岩都明显来自地幔然而他们有不懂的组成。

Both island arc and mid-ocean ridge magmas apparently come from the mantle yet they have different compositions .

西昆仑造山带花岗岩存在6个大的侵入旋回和9个侵入期，分别形成于洋脊环境、火山弧环境、碰撞后隆起环境和造山晚期相对拉张环境。

There are six intrusive cycles and nine intrusive periods of granitoids in west Kunlun orogenic belt . The granitoids were formed in ocean ridge , volcanic arc , syn_collision , post_collision uplift and late orogenic environments respectively .

北祁连是我国重要的成矿带之一，其主要构造单元由微陆块、混杂岩带、蛇绿岩、洋脊&洋岛火山岩、岛弧火山岩及岛弧型沉积岩组成。

The north Qilian area is one of important metallogenic belt of China , and it is composed of microcontinent , ophiolite , m é lange belt , ocean ridge and ocean island volcanic rocks , island arc volcanic rocks and island arc sediment rocks .

它是秦岭与扬子之间的缝合带，为一典型的蛇绿构造混杂带，由超基性岩、辉长岩（堆晶辉长岩）、辉绿岩墙群、洋脊玄武岩和岛弧火山岩构成。

It is the suture zone between Qinling and Yangtze plates . It is a tectonic melange , consisting of tectonic blocks of ultrabasic rocks , gabbros ( accumulative gabbros ), diabasic dike swarms , mid & ocean ridge basalts and island arc volcanic rocks .

火山岩形成的构造环境，是在扬子地块西缘基础上发展起来的裂谷洋盆，块状火山岩发育于裂谷洋盆中央（准洋脊），层状火山岩则发育于裂谷洋盆的陆缘斜坡（次大陆）。

The structural environment forming the volcanic rocks was a rift ocean basin developed along the west margin of the Yangzi Massif . The massive volcanic rocks were developed in the centre of the rift ocean basin but the bedded ones were developed on the epicontinental slope ( subcontinent ) .