The qiongzhong and danxian batholiths , as the largest early mesozoic syntectonic granite intrusions in hainan island , are mainly composed of porphyritic biotite two - feldspars granitoids , in which alkali - feldspar phenocrysts and dark minerals are foliated mostly in we - direction . the granites are of metaluminous i - type . major and trace elements show co - variations with sio2 , suggesting the fractional crystallization of plagioclase , hornblende , apatite and ti - fe oxides in the evolution of the granites 花岗岩的主量元素和部分微量元素成分与sio _ 2呈良好的相关关系，显示出明显的斜长石、角闪石、磷灰石和ti - fe氧化物等的分离结晶作用，总体上它们与大陆岛弧花岗岩的微量元素丰度和分布特征相似，系统地亏损ba 、 nb 、 sr 、 p和ti等元素。
2.
Geotectonically , the youjiang sedimentary basin was referred as youjiang yindosinian folded belt . triassic turbidites accumulated in the basin were derived from surrounding ancient lands including yuebei , jiangnan , and yunkai . tectonic setting of the sedimentary basin was in between an active continental margin and a continental island arc 赋矿浊积岩系的主要物源区为盆地周围的“越北古陆” 、 “江南古陆”和东边地区包括钦防海西褶皱带在内的“云开古陆” ，沉积构造背景介于大陆岛弧和活动大陆边缘之间的过渡构造环境。
