【摘要】 楚山花岗闪长岩体产在佳木斯隆起内,与元古界麻山群变质岩系密切伴生,呈交代-侵入接触,并侵入震旦系龙山村群。岩体的Rb-Sr等时线年龄626Ma,K-Ar年龄670Ma,属兴凯旋回早期。岩体呈巨大岩基,受南北向牡丹江深断裂控制。主要岩性为花岗闪长岩,局部为花岗岩及石英闪长岩。岩相学上既显示岩浆结晶特点又有交代作用的迹象。按其矿物-地球化学特征属半原地的S型花岗岩类,⁸⁷Sr/⁸⁶Sr初始值为0.710,原岩浆为陆壳部分熔融的产物。更多还原

【Abstract】 The Chushan granodiorite body, being situated in Jiamusi median massifs of the geosynclinal region of northern China, is closely associated with the Paleozoic Mashan Group of metamorphic rocks by a metasomatic-intrusive contact. Having the Rb-Sr isochron age of 626 Ma and K-Ar age of 670 Ma, it belongs to Early Xingkainian stage. This granodiorite body, occurring as a huge elogated batholith, is controlled by a N-S abyssal fault and is composed mainly of granodiorite, monzonitic granite and quartz diorite. Petrographically, it presents not only the characteristics of magmatic differentiation, but also traces of metasomatism and seems to be a so-called subautochthon with mineralgeochemical characteristics of S-type granite. It is suggested that the Chushan granodiorite boby can be considered as a product of granitic magma from partial melting in the continental crust, which is proved by the initial ⁸⁷Sr/⁸⁶Sr ratio of 0.7104.更多还原