期刊文献+

胶西北两类金矿床暗色脉岩的碳、氧同位素地球化学研究 被引量:11

OXYGEN AND CARBON ISOTOPE GEOCHEMISTRY OF DARK DIKES IN TWO TYPES OF GOLD DEPOSITS OF NORTHWEST JIAODONG PENINSULA
下载PDF
导出
摘要 胶西北部金矿床矿化过程伴生的暗色脉岩是以煌斑岩为主的钾玄岩高钾钙碱性岩。详细研究其两类代表性矿床的脉岩内碳酸盐碳、氧同位素和全岩氧同位素发现 ,石英脉岩型矿床的δ18OSMOW ,方解石 为 10 .2‰~ 11.6‰、δ13 CPDB ,方解石 =- 3.5‰、δ18OSMOW ,全岩 为 5 .8‰~ 6 .6‰ ,蚀变岩型矿床的δ18OSMOW ,方解石 为 7.18‰~ 8.6 6‰、δ13 CPDB ,方解石 为 - 0 .7‰~ 0 .93‰、δ18OSMOW ,全岩 为 6 .9‰~10 .6‰。通过对源区的δ13 CPDB、δ18OSMOW特征和同位素效应与就位环境关系的讨论 ,初步认为 :两类矿床的暗色脉岩为同源岩浆演化的产物 ,初始岩浆来源于洋壳俯冲提供流体与岩石圈地幔发生交代作用而形成富集地幔。两类矿区暗色脉岩的碳、氧同位素体系的相对独立性与岩浆演化过程就位环境有关。 The dark dykes in gold deposits with two types of northwestern Jiaodong peninsula, belong to a suite of high potasium, calca alkaline rock series, such as lamprophyres, andesite pophyrites and dacite pophyrites. Isotopic analysis data of whole rock and carbonate minerals in dykes, shown that in quartz vein type deposits δ 18 O SMOW,whole rock is 5.8‰~6.6‰, δ 18 O PDB,calcite is 10.2‰~11.6‰ and δ 13 C PDB,calcite 3.5‰, in altered rock type deposits δ 18 O SMOW,whole rock is 6.9‰~10.6‰, δ 18 O SMOW calcite is 7.18‰ ~8.66‰, δ 13 C SMOW calcite is -0.7‰~0.93‰.These data were used to determine the δ 18 O SMOW,whole rock , δ 18 O SMOW calcite and δ 13 C PDB,calcite values of the magmas in the source region and to study the isotope exchange of the magmas with the country rocks. Combined with the study of the geological setting for emplacement of the dykes, it is suggested that the magmas forming the dark dykes in the gold fields are products of the evolution of the cognate magmas. The parent magmas originated from an enriched mantle, which experienced metasomatism of the lithosphere mantle with the fluids that were generated during the subduction of the oceanic plate and then infiltrated into the lithosphere. Different isotopic effects in the evolution of magma seem to have been the main factors leading to the distinctive features of carbon and oxygen isotopes in gold deposits with two types.
出处 《吉林大学学报(地球科学版)》 EI CAS CSCD 北大核心 2002年第1期11-15,共5页 Journal of Jilin University:Earth Science Edition
基金 国家自然科学基金重点项目 (4 913312 ) 中国科学院知识创新工程项目 (KZCX10 7) 南京大学内生金属矿床成矿机制研究国家重点实验室 吉林大学青年教师基金资助
关键词 暗色脉岩 碳-氧同位素 地球化学 金矿床 煌斑岩 岩浆 dark dikes O C isotope geochemistry goldfields of northwest Jiaodong
  • 相关文献

参考文献6

二级参考文献57

共引文献175

同被引文献264

引证文献11

二级引证文献241

相关作者

内容加载中请稍等...

相关机构

内容加载中请稍等...

相关主题

内容加载中请稍等...

浏览历史

内容加载中请稍等...
;
使用帮助 返回顶部