【摘要】 广西花山-姑婆山燕山期花岗岩体以高硅、高钾、富碱、低磷、准铝质为特征,具有较高的 TFeO/MgO 值,富集大离子亲石元素、高场强元素和稀土元素,普遍出现褐帘石,应归属于富钾的钙碱性花岗岩(KCG)系列岩石,相当于高钾钙碱性Ⅰ型花岗岩。产生于后造山陆内挤压向拉张转换的地球动力学背景下,其形成与岩石圈伸展-减薄、亏损地幔岩浆的上涌和富含金云母-钾质碱镁闪石的岩石圈地幔的部分熔融有关。更多还原

【Abstract】 The Yanshanian Huashan-Guposhan granites in Guangxi are characterized by high silicon,high potas- sium,high alkaline,low phosphor and metaluminous nature,with relatively high FeO~T/MgO ratios and enrich- ment of LILE,HFSE and REE.In addition,they commonly contain allanites.They can thus be assigned to the high-potassium calc-alkaline granite(or KCG in the classification system of Barbarin,1999).They were formed during the conversion of the tectonic setting from compression to extension.The extension-thinning of litho- sphere,the upwelling of the depleted mantle,and the partial melting of the lithospheric mantle rich in phlogo- pite and K-richterite might have served as the principal factors in producing this kind of granitic rocks.更多还原