火山岛弧

在微量元素构造判别图上，火山岩样品集中在火山岛弧和弧后盆地的范围内。

On tectonic discrimination plots of trace elements , all samples of volcanic rocks fall into the field of volcanic island arc and back arc basin .

其物源主要来自其西侧的大凹子火山岛弧。

Its provenance is the Dawazi volcanic island-arc on the west side .

前者是中甸岛弧带与扬子地台的构造分界线，而后者则将岛弧带内的东、西两个火山岛弧带分开。

The former is the boundary line of Zhongdian Island Arc Belt and Yangtze Platform ;

火山岛弧主要由中基性火山岩、细碎屑岩等组成，成岩时代为晚寒武世&奥陶纪。

The volcanic island-arc zone is chiefly composed of intermediate-basic volcanic rocks and fine clastic rocks , which formed during the Late Cambrian-Ordovician .

这一研究反映了哈尔里克泥盆纪火山岛弧经过了由拉伸作用到碰撞挤压造山引发的A型俯冲作用演变过程，并产生了上述相应的变质现象

Detailed research suggests the following tectonic evolution model : Thermal metamorphism was related to intra island arc tension , while regional faulting metamorphism was caused by A type subduction in the process of collisional orogeny . Phenomenon

古中元古代时，琼中屯昌变基性-超基性岩，为大洋型火山岛弧低钾拉斑玄武岩，明显具有镁铁质-玄武质科马提岩特征，来源于高度亏损的地幔；

At the Paleo-Mesoproterozoic era , the meta-basic-ultrabasic rocks on eastern Hainan are oceanic low K arc tholeiite with the features of mafic-basaltic komatiite evidently , originated from highly depleted mantle and are formed under the tectonic setting of volcanic arc .

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 .

其原岩岩石类型有火山岩，陆缘碎屑沉积岩，火山、岛弧拉斑系列或钙碱系列火山岩、蛇绿岩等。

Their original rocks are volcanic rocks , epicontinental clastic sedimentary rocks , and ophiolite of volcanic and island arc tholeiitic series or calcium alkali series .

该套火山岩主要为中基性火山岩与中酸性火山岩，岩石化学显示为为低钾的钙碱性玄武岩系列，地球化学也显示火山岩具有岛弧火山岩的特征。

These volcanics are mainly intermediate and basic volcanics and intermediate and acidic volcanics and are low K sub-alkaline series and calc-alkaline basalt series by rock chemistry and indicate arc volcanics by geochemistry .