地质学报2011，Vol.85Issue(5)：834-848,15.DOI:CNKI:11-1951/P.20110512.0910.015
宁芜盆地陶村铁矿床磷灰石的LA-ICP-MS研究
A LA-ICP-MS Study of Apatite from the Taocun Magnetite-apatite Deposit, Ningwu Basin
摘要
Abstract
Ningwu volcanic basin is one of the important deposit-intensive areas along the Middle-Lower Reaches of Yangtze River metallogenic belt. Apatite is one of the key diagnostic minerals for a variety of deposits in this area.Taking the Taocun iron deposit, one of representative porphyrite irons in Ningwu basin, as an example, this study examined trace elements and major elements compositions of the apatites (Ap-I, Ap-D, Ap-V) from pyroxene diorite porphyrite, disseminated magnetite ores and using electron microprobe and LA-ICP-MS methods. The results show that the apatite (Ap-I) from pyroxene diorite porphyrite and apatites (Ap-D and Ap-V) changes within a small range in compositions, suggesting they are fluorapatite with minor S and Cl. But the apatite (Ap-I)contains higher contents of Ns, Mg, Si, V, Mn, Fe, Ga, Ge, Sr, Y, Zr, Ba, REE, Pb, Th, and U. Other than higher Ns, Mg, Si, V, Mn, Fe, Ga, Ge, Sr, Y, Zr, Ba, REE, Pb, Th, and U, the apatite (Ap-D) also contains Al, Sc, Cr, Ni, and Cu. Only difference between Ap-V and Ap-D is that the apatite (Ap-D) contains lower Al, Sc, Ct, Ni, and Cu, with a few values higher than instrumental limit. The evolution relationships between Zr, Y, Lu, Yb, Mn, andδEu, and the REE distribution pattern in the apatites (Ap-I, and Ap-D and ApV ) from magmatic rocks and two kinds of ores indicate that the ore-forming fluids may derive from pyroxene diorite porphyrite, and oxygen fugacity of the ore-forming fluids increased from disseminated mineralization to vein mineralization but contents of Y and REEs in the fluids decreased. The Taocun iron deposit is a magmatie hydrothermal deposit closely related to diorite porphyrite. Compared with the Kiruna-type deposit and IOCG deposits, the Taocun iron deposit shows distinct differences in the geochemical compositions of the apatites,indicating that the Ningwu porphyrite iron deposit, which is represented by the Taocun iron deposit, belongs neither to the Kiruna type deposits nor to the IOCG type deposit.关键词
LA-ICP-MS/磷灰石/微量元素/陶村铁矿床/宁芜盆地Key words
LA-ICP-MS/ apatite/ trace elements/ Ningwu basin/ Taocun magnetite-apatite deposit引用本文复制引用
张乐骏,周涛发,范裕,袁峰,钱兵,马良..宁芜盆地陶村铁矿床磷灰石的LA-ICP-MS研究[J].地质学报,2011,85(5):834-848,15.基金项目
本文为国家自然科学基金项目(编号40830426)、高等学校博士学科点专项科研基金(编号20100111110010)、国家"深部探测技术与实验研究专项计划"专题(编号SinoProbe-03-02-05)、中国地质调查局地质调查工作项目(编号1212011121115)和澳大利亚塔斯马尼亚大学国家优秀矿床研究中心科研基金(编号CODES2009 P2.N3)资助的成果. （编号40830426）
