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胶东金矿区矿田体系产出的脉岩是一套富含碳酸盐矿物相的中基性 -中酸性脉岩 ,岩石类型主要有煌斑岩、安山玢岩类。对部分矿田体系产出脉岩的碳酸盐 (方解石 )碳、氧同位素及全岩氧同位素的研究表明 :该套脉岩的δ18OSMOW ,方解石 、δ13 CPDB ,方解石 和δ18OSMOW ,全岩 值分别为 6 .9‰～ 11.6‰、- 0 .9‰～ - 3.6‰、5.8‰～ 7.4‰。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探讨 ,初步认为 :各矿田内的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的流体与岩石圈地幔发生交代作用而形成的富集地幔 ,源区的δ18OSMOW ,碳酸盐 、δ13 CPDB ,碳酸盐 、δ18OSMOW ,岩浆 分别为 9.2‰±、- 4 .4‰±和 5.8‰± ;岩浆演化过程中同位素效应的差异是导致各矿田体系脉岩的碳、氧同位素相对独立的主要原因
The vein rock produced by the orefield system in Jiaodong gold mine area is a set of middle-basic-intermediate acid vein rocks rich in carbonate minerals. The rock types are mainly lamprophyreite and andesite. Carbonate, oxygen isotopic compositions and whole-rock oxygen isotopes of carbonate rocks (calcite) from some orefields indicate that δ18OSMOW, calcite, δ13CPDB, calcite and δ18OSMOW of the veins of this orefield are 6 .9 ‰ ~ 11.6 ‰, -0.9 ‰ ~ 3.6 ‰, 5.8 ‰ ~ 7.4 ‰. Based on the discussion of the relationship between the δ13CPDB, δ18OSMOW characteristics and the situ environment in the source area, it is preliminarily considered that the vein rock in each ore field is the product of the evolution of the same magma; the initial magma is derived from the fluid and lithosphere Enriched mantle formed by the mantle metasomatism. The δ18OSMOW, carbonate, δ13CPDB, carbonate and δ18OSMOW in the source area are 9.2 ‰ ± -, -4.4 ‰ and 5.8 ‰, respectively. The magmatic evolution The differences in the mid-isotope effect are the main reasons for the relative independence of carbon and oxygen isotopes in the veins