麻棚岩体特征及其与金矿成因关系研究

来源期刊：中南大学学报(自然科学版)1994年第3期

论文作者：张亚雄 胡祥昭

文章页码：275 - 281

关键词：麻棚岩体; Ⅰ型花岗岩; 金矿; 成矿母岩

Key words：Mabeng granitic intrusion; Ⅰ-type granite; gold ore; mother rocks for gold min-eralization

摘    要：麻棚岩体出露于土岭－石湖金矿田西北部,与围岩阜平群的变质岩成侵入接触关系.岩体内岩相分带清楚,矿物组成相对较简单,岩石化学特征反映其为铝、碱过饱和的角闪石黑云母花岗岩,岩石地球化学特征表现出金含量高,浓集系数达12.2,稀土元素特征表明岩体不同相带为同源分异产物.与岩体有成因联系的石英闪长玢岩及花岗闪长斑岩空间上与金矿脉密切共生,或其本身就是含金脉岩,说明麻棚岩体为岩浆成因——相当于Ⅰ型花岗岩,其成岩物质来自上地幔或下地壳,它不但为矿田内金矿的形成提供热源,在某种程度上可谓成矿母岩.

Abstract: Mabeng granitic intrusion,which occurs in the northwestern T-S gold ore field, presentsintrusive contact with the country rocks.Its facies zoning is obvious and its mineral compo-nents are relatively simple,Its petrochemical characteristics indicate that it is hornblende-bi-otite granite with aluminium-alkali supersaturation,while its petrogeochemical features dis-play a higher gold content with a concentrational coefficient of 12.2.Moreover,the REE ofthe intrusion suggests that the different facies zones in it are the differentational results ofthe magma from the same source,The quartz-diorite-porphyrite and the granodiorite-por-phyry veins , which are originally related with the intrusion, are closely paragenesis with thegold ore lodes in spatial distribution,or in some places,they are the gold-bearing veins them-selves,So all these aspcts prove that the Mabeng body is originally magma intrusion,and be-longs to the Ⅰ-type granite genetically.The original magma was either from the upper mantalor the down crust. The intrusion acted not only as a‘heat engine’but also as mother rocksfor the gold mineralization in the T-S ore field.