吉黑东部花岗岩类的稳定同位素组成

吉黑东部花岗岩类分布广泛，形成历史漫长，岩石类型齐全。按成因类型划分，以I型为主，A型次之，S型很少，M型极少。其稳定同位素组成独特，大多数岩体锶初始值低，氧同位素正常或低，铅同位素以低^204Pb和高^206Pb/^204Pb、^207Pb/^204Pb、^208Pb/^204Pb为主，钕初始值高，说明其基底岩石成熟度低，地幔物质混入量较多。这些特点明显区别于华北和华南的花岗岩。

Stable Isotope Composition of Granitoids in EasternJilin and Heilongjiang Provinces

The granitoids broadly distributed in eastern Jilin and Heilongjiang have long formation history and complete types. Genetically, the granites are mainly of I_type, with subordinate A_type, minor S_type and rare M_type. The stable isotope compositions of most rock bodies are characterized by low initial Rb_Sr values, normal or lower oxygen isotope values, low 204 Pb , high 206 Pb/ 204 Pb , 207 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios, and high Nd initial values. These features show that, mixed with much mantle material, the basement rock has low maturity. These characteristics are obviously different from those of the granites in North and South China.