摘要
对镇圩式金矿矿床地质特征及矿物学的研究表明 ,该类矿床产于峰林洼地、岩溶漏斗等岩溶地貌中 ;赋矿主岩为红色中度—次强富铝风化壳 ,其风化壳剖面由下而上的变化特征为 :粘土矿物由 2∶1型向 1∶1型变化 ,锰结核及铁的氧化物增多 ,硅、碱金属含量降低 ,铝、铁含量增加 ;自然金形状为不规则粒状、片状、树枝状、针状、浑圆状、次浑圆状 ,并常与锑钙石、针铁矿、软锰矿连生 ;金矿源体为叫曼式金矿。文章指出金矿由堆积、淋积作用形成 ,为岩溶洼地堆积、淋积改造红土型金矿 。
Through the geological and mineralogical study of the Zhenxu_type gold deposits, the authors hold that this type of deposits are distributed in the peak forest_depression and funnel of karst landforms. The gold source is Jiaoman_type gold deposit. The host is an auriferous red weathering crust, which can be classified into the upper and the lower layers in section. From the lower layer to the upper one, the composition of the clay minerals changes from 2∶1 type to 1∶1 type, manganese nodule and Fe oxide increase, SiO 2 and K 2O+Na 2O decrease, and Al 2O 3 and Fe 2O 3+FeO increase; the weathering crust is thus of intermediate_relatively rich aluminium type. The gold orebodies in the two layers assume stratiform, lenticular and irregular forms. The ores mainly consist of clay minerals. The clastic constituent of the ore is mainly romeite, which is an important key to find the gold_rich orebody. The romeite occurs within the gold ore in the ellipsoidal and perfectly round shapes. The native gold, which takes irregular, schistose, branching, needle_like, perfectly rounded or subrounded forms, is associated with romeite, goethite and pyrolusite. Ores consist mainly of SiO 2, Al 2O 3, Fe 2O 3 and CaO. It is pointed out that the Zhenxu_type gold deposits, a special kind of laterite_type gold deposits in South China, were formed by the accumulation and leaching_sedimentation during the lateritization, thus belonging to the laterite_type gold deposits characterized by karst depression accumulation and leaching_sedimentation transformation. The determination of this type of deposits, the formulation of the metallogenic model and the researches on the regularity of the gold concentration can play important guiding roles in the prospecting for this kind of gold deposits.
出处
《矿床地质》
CAS
CSCD
北大核心
2001年第3期251-258,共8页
Mineral Deposits
基金
冶金部黄金地质科研课题 (96_98_4_2 )
关键词
红土型金矿床
地质特征
成矿模式
广西
淋积作用
金矿源体
自然金
Laterite_type go1d deposit, Zhenxu_type go1d deposit, geo1ogical characteristics, mate11ogenic mode1, Guangxi
