胶东金矿区矿田体系中基性—中酸性脉岩的碳，氧同位素地球化学研究

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、δ13CPDB，方解石和δ

Research on C, O IsotopicGeochemistry of Intermediate_Basic and Intermediate_Acid Dykes In Goldfields of JiaodongPeninsula

The intermediate_basic and intermediate_acid dykes existent inthe gold fields of Jiaodong peninsula, China, belong to a suite of intermediate_basic and intermediate_acid carbonate minerals_rich rocks consisting of lamprophyres and andesite porphyrites. Detailed studies of carbon and oxygen isotopes of carbonate minerals of the dykes and oxygen isotopes of the dykes in the gold fields (i.e. Linglong, Rushan and Sanjia gold deposits) show that δ13CPDB, calcite, δ18OSMOW calcite and δ18OSMOW,whole-rock values of the intermediate_basic and intermediate_acid dykes in the gold fields are in the range of -3.6‰～-0.9‰, 6.9‰～11.6‰ and 5.8‰～7.4‰ respectively. These data were used to determine the δ18OSMOW,whole-rock, δ18OSMOW calcite and δ13CPDB，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 intermediate_basic and intermediate_acid dykes in the gold fields are products of the evolution of the cognate magmas. The parent magmas originated from an enriched mantle (δ18OSMOW，carbonate：9.2‰、δ13CPDB，carbonate：-4.4‰ and δ18OSMOW, magma: 5.8‰), 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 the gold fields.