强力侵位花岗岩体与金矿的关系——以丹东三股流岩体为例

辽宁丹东五龙金矿、四道沟金矿位于五龙背—大堡花岗岩体与三股流花岗岩体之间,成矿作用与三股流岩体密切。据分析,这两个岩体的岩浆来源相同,岩石化学性质相似,岩体侵位时间相当,且同处于丹东北东向韧性剪切带内,但由于岩体侵位时受控的局部构造环境不同,导致岩体以不同的方式侵位。三股流岩体在韧性推覆剪切带发展演化过程中沿剪切面理以气球膨胀式强力侵位;而五龙背—大堡岩体则是沿该剪切带晚期发育的北西向脆性张裂面被动侵位。不同方式侵位的岩体具有不同的成岩环境,从而在一定程度上控制岩浆气水溶液的分离和聚集。强力侵位的花岗岩体在成岩过程中具有较好的封闭条件,因此可能有利于成矿热液的分泌、聚集和保存,而被动侵位的花岗岩体则不具备这种有利的成矿条件。

THE STRUCTURAL CHARACTER OF SYNTECTONIC GRANITE BODY WITH FORCEFUL EMPLACEMENT AND ITS RELATIONSHIP WITH THE GOLD DEPOSIT: THE EXAMPLE OF SANGULIU GRANITE BODY, DANDONG

Wulong and Sidaogou gold deposits are located between Wulongbei-Dapu and Sanguliu granite bodies, which are similar in magmatic origin and its chemistry as well as the age of their emplacement, and both coexist in NE-trending ductile shear zone, but are differenrt in emplacement mechanism because the tectonic conditions controlling their emplacement are partially different. During the evolution of the ductile shear zone, Sanguliu granite body forcefully intruded along the shear foliation with a "balloning mechanism", however, Wulongbei-Dapu granite body passively intruded along NW-trending tensional fractures which were developed at Later period of the evolution of shear zone. Granite body with forceful emplacement has fairly good closed environment in the rock-forming process, so that it is favourable to the secretion, concentration and preservation of hydrothermal ore-forming solution, but granite body with passive emplacement has not this kind offavourable mineralizing environment.