辽南望海寨钼矿床地质特征及找矿意义

Geologic Features and Prospecting Significance of the Wanghaizhai Mo Deposit in Southern Liaoning

望海寨钼矿床是辽南地区发现的斑岩型钼矿床,由南、中、北3个矿化带组成,矿化赋存在似斑状花岗岩中,矿化类型为细脉-浸染状,发育斑岩型钼矿床典型的钾化、黄铁绢英岩化、青磐岩化等围岩蚀变组合。含矿岩体为似斑状花岗岩,具有高SiO_2和Al_2O_3、富K_2O、Na_2O,低CaO、TiO_2等特点,属于钙碱性系列,与俯冲带岩浆地球化学特征类似,岩石成因可能与俯冲作用有关。该矿床的发现对该成矿带找矿具有现实指导意义。

The Wanghaizhai Mo deposit is a typical porphyry deposit in southern Liaoning. The Mo mineral- ization occurs in a porphyroidtexture granite intrusion, and consists of three mineral belts. The country rock alteration displays distinctive porphyry deposit alteration assemblages, including K--feldspathisation, pyrite--sericitization, and propylition. The Mo--bearing granite intrusion contain high SiO2, Al2O3, K2O, Na2O, and low CaO and TiO2. It belongs to cala--alkaline, and compatible with the geochemical features of subduction magma, suggesting the petrogenesis associated with subduction. Combining region- al geological evolution, author considers that Wanghaizhai Mo deposit may have been formed as a result of the Pacific plate subduction to the Eurasian plate in the Mesozoic era. Successful finding of the deposit pro- vides experience for porphyry Mo deposit in the southern Liaoning, and has actual significance for prospec- ting in the area.