【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。更多还原

【Abstract】 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.更多还原