摘要
对于闽粤地区马坑式铁矿的成因,存在着不同的解释:一是认为是沉积-热液再造矿床或火山沉积变质矿床,主要受岩相古地理条件和火山作用控制;另一认为是接触交代成因,受地层岩性、构造和花岗岩体三个因素控制。尖山铁矿成矿地质特征,在粤东具有一定的代表性。
The characteristics of the formation of the Jianshan iron deposit is a typical example among the iron deposits of this type in eastern Guangdong.The localization of the iron deposit is controlled by the contact zone of Jianshan granite and the limestones belonging to various units(from the upper part of Lower Carboniferous to the Lower Permian Qixia Formation).The ore bodies in the northeasttrending downwarpsare arranged en echelon The Jianshan granite is a small marginal stock of Wuping-Dabagranitic batholith,and intruded in the early stage of the Yanshanian Orogeny with an isotopic(K-Ar)age of 147.3m.y.According to the geological data and triclinity of the potash feldspar it was formed at a depth of 2—3 km and at a temperature from 600°to 700℃.The iron ore is nothing but a magnetite-bearing skarn,being mineralized during one of the stages of the contact metasomatism.A series of repeated magnetitization gave rise to several generations of magnetite,which occurs in two forms,i.e.,the filling-magnetite and the metasomatic type,both being formed within a temperature range of 310°to 560℃.Geological evidences and isotopic data suggest that the iron was derived from various sources,including the possibility of partially sedimentary in orgin,but their transportion was closely related to the action of the potash-bearing fluids.
作者
叶庆同
吴学汉
李慕洁
邓仕侬
Ye Qingtong;Wu Xuehan;Li Mujie;Deng Shinong(Institute of Mineral Deposits of the Chinese Academy of Geological Sciences;Geological Team No.723,Guangdong Bureau of Geology)
出处
《地质学报》
1980年第3期219-232,共14页
Acta Geologica Sinica
