摘要
九瑞矿集区隶属于长江中下游铜-铁-金成矿带,该矿集区内主要发育有武山、城门山、洋鸡山、丁家山等大中型铜金多金属矿床。区内的南港成矿远景预测区位于横立山-黄桥向斜的南翼,地质条件与该向斜北翼的武山铜矿基本一致。本文以南港地区发现的煌斑岩为研究对象,对其中的辉石进行了详细的岩相学和电子探针成分分析工作,来探讨煌斑岩的演化过程及岩石成因。测试结果显示,南港煌斑岩中的辉石,具有高Ca、高Mg,低Ti,贫Al、贫Fe的特点。斑晶中的辉石属于透辉石和普通辉石,基质中的辉石则属于普通辉石。辉石斑晶的viAl和Na2O含量很低,指示其形成压力较小。由早到晚从斑晶到基质,辉石向着富铁富钙的方向演化。辉石发育有反环带及韵律环带,显示在岩浆房中可能受到过岩浆混合作用的影响。辉石的矿物化学特征指示南港煌斑岩属碱性岩石系列。
The Jiurui ore district belongs to the Middle-Lower Yangtze River Mineralization Belt. In this area,there are many large and medium-scale copper deposits such as Wushan,Chengmenshan,Yangjishan and Dingjiashan. The Nangang copper prospecting area is located in the south of the Wushan ore deposit,and its geological conditions are similar to Wushan. This study focuses on the lamprophyres sampled from boreholes in the Nangang area. We carried out a detailed mineral chemistry study of pyroxene and discussed the magma evolution and petrogenesis of the lamprophyre. The results showed that the pyroxenes from the lamprophyre have a composition of high Ca and Mg,low Ti,poor Al and Fe. The pyroxenes belong to the augite and diopside,and they crystallized in lower pressure. From phenocryst to matrix,chemical compositional evolution of the pyroxenes is in the direction of Fe-rich and Ca-rich.The occurrence of reverse zoning and rhythm zoning of pyroxenes indicates a magma mixing process in the magma chamber. The features of mineral chemistry show that the host lamprophyres belong to alkaline series.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第3期675-685,共11页
Acta Petrologica Sinica
基金
科技部973项目(2012CB416706)
"十二五"国家科技支撑计划(2011BAB04B03)联合资助
关键词
矿物化学
煌斑岩
辉石
成分环带
九瑞地区
Mineral chemistry
Lamprophyre
Pyroxene
Zonation
Jiurui district