牡丹江地区砾岩金矿地质特征及成矿预测

牡丹江地区分布的晚侏罗世穆棱组地层的底部砾岩普遍含金,并常常构成工业矿体。矿体的规模、形态和分布范围严格受底砾岩的控制。底砾岩为河流冲积相的产物,而古河道则发育于地洼盆地内。因此,地洼构造活动对底砾岩的形成起了重要的作用。盆地内不同地段的底砾岩在砾石成分、砾径大小、磨圆度和重矿物等方面均具有明显的差别,这些差别表明从小金山—西楼—平岗到二站可能为同一水系。据此,对未知地段进行了预测。

PRELIMINARY RESEARCH ON THE GEOLOGLCAL FEATURES AND THE METALLOGENIC PROGNOSIS OF CONGLOMERATE TYPE GOLD DEPOSITS, MUDANJIAN REGION

Some gold deposits occur in the bottom conglomerates of Mulin Formation (Late Jurassic Period) which are distributed widely in Mudanjian area. The shapes, the scales, and the distribution ranges of the gold deposits are strictly controllefl by the bottom conglomerates which belong to the river alluvial deposit, and the rivers only developed in Diwa Basin. Therefore, Diwa tectonic movement played an important role in the formation of the bottom conglomerates. There are some obvious differences among the gravel composition, grain size and psephicity and heavy minerals of the different bottom conglomerates, and these differences show that there is a river along Xiaojinshan--Xiliuo--Pinggang --Erzhan. And the metallogenic prognosis is given here.