湖南锡矿山锑矿矿区煌斑岩的地球化学特征
Geochemical characteristics of lamprophres in the Xikuangshan antimony oredeposits, Hunan province
-
摘要: 对湖南锡矿山矿区煌斑岩脉进行了系统的元素和同位素地球化学研究,来探讨煌斑岩的成因。本区煌斑岩形成时代大约为120Ma,早于锑成矿时间,并与锑成矿有密切相关。其微量元素MORB蛛网图,以富集高场强元素,Nb-Ta亏损和Ti不亏损,Th强富集和Ce弱富集为特征,具有岛弧型玄武岩微量元素分配模式,构造环境可能为大陆内部破坏板块边缘。稀土元素具有总量高,无明显的负铕异常,配分模式呈轻稀土富集的右倾型特征。同位素以高^87Sr/^86Sr、低^143Nd/^144Nd为特征。结合元素地球化学、同位素特征和地质发展史分析,煌斑岩可能为富含REE和高场强元素的俯冲带流体交代过的富集地幔部分熔融所产生的岩浆,在上升过程中同化和混合很少量的矿区隐伏花岗岩浆和灰岩的产物。Abstract: Element and isotope geochemistry of the lamprophyres veins in the Xikuangshan antimony ore deposits issystematically researched in this article, aiming at discussing genesis of lamprophyres. The lamprophyres studied were formed ca 120Ma ago, prior to mineralization chronology, and is considered to be closely related to antimony mineralization in the Xikuangshan area. The MORB-normalized spidergrams of samples studied are rich in high field element, with depleted Nb-Ta and non-depleted Ti, strong enrichment in Th and weak enrichment in Ce, being similar to spidergrams of volcanic arc basalt. Their tectonic setting probably is destructive plate boundaries of an inter continent. The rare-earth element of sample studied have characteristics of high total contents and non-distinct Eu anomalies. The chondrite-normalized REE patterns are right-inclined. The isotopic contents of sample have high 87 Sr/87 Sr and low 143Nd/144 Nd. Combining element and isotope geochemistry with geological history, the lamprophyres studied in the area result from partial melting of enriched REE and HSFE fluid related to subduction of metasomatic mantle, mixing with a little underlying granite and limestone compositions.
-
Key words:
- Lamprophyres /
- Geochemistry /
- Xikuangshan antimony ore deposits /
- Hunan /
-
[1] 李献华 胡瑞忠.粤北白垩纪基性岩脉的年代学和地球化学[J].地球化学,1997,26(2):14-31,.
[2] 解庆林 马东升.锡矿山锑矿床方解石的地球化学特征[J].矿产与地质,1996,10(2):94-99,.
[3] 吴良士 胡雄伟.湖南锡矿山地区云斜煌斑岩及其花岗岩包体的意义[J].地质地球化学,2000,28(2):51-55,.
[4] 王岳军 范蔚茗 等.湘东南中生代花岗闪长质小岩体的岩石地球化学特征[J].岩石学报,2001,17(1):169-176,.
[5] 周辉 李继亮.西昆仑库地煌斑岩的年代学及地球化学特征[J].岩石学报,2000,16(3):380-384,.
[6] 彭建堂 胡瑞忠.湘中锡矿山超大型锑矿床的碳、氧同位素体系[J].地质论评,2001,47(1):34-41,.
[7] 彭建堂 胡瑞忠 等.湘中锡矿山锑矿床的Sr同位素地球化学[J].地球化学,2001,30(3):248-256,.
[8] Zhou Xinming,Tectonophysics,2000年,326卷,3/4期,269页
[9] 凌水成,有色金属矿产与勘探,1999年,8卷,6期,447页
[10] 徐义刚,化学地球动力学,1999年,119页
[11] 金景福,湘中锡矿山式锑矿成矿规律及找矿方向,1999年,1页
[12] 黄智龙,云南老王寨金矿区煌斑岩成因及其与金矿化的关系,1999年,30页
[13] 赵振华,中国科学,1998年,增刊,7页
[14] 湖南省地质矿产局,湖南省区域地质志,1998年,478页
[15] 赵振华,微量元素地球化学原理,1997年,112页
[16] Sun S S,Ore Geol Rev,1996年,10卷,3/6期,339页
[17] Hu Xiongwei,Resource Geology,1996年,46卷,4期,227页
[18] 饶家荣,湖南地质,1993年,增刊,68页
[19] 史明魁,湘中锑矿,1993年,1页
[20] 任纪舜,地质学报,1990年,64卷,4期,275页
[21] Sun S S,Geol Soc Spec Publ,1989年,42卷,313页
[22] 刘焕品,湖南地质,1985年,4卷,1期,28页
[23] 刘光模,矿床地质,1983年,2卷,3期,43页
计量
- 文章访问数: 8283
- PDF下载数: 6659
- 施引文献: 0