青南高原中东部砂金成矿条件与找矿标志

METALLOGENIC CONDITIONS AND PROSPECTING CRITERIA FOR PLACER GOLD DEPOSITS IN THE CENTRAL-EASTERN PART OF THE SOUTHERN QINGHAI PLATEAU

青南高原中东部,处于巴颜喀拉山冒地槽带。平均海拔4500m 以上,由黄河源丘状山原盆地区及通天河中段—黄河上段大中起伏高山河谷区组成二级地貌区。研究者对该区近代砂金矿的形成与分布规律,金的物质来源、水动力条件、新构造运动及地貌条件进行分析并指出区内寻找近代砂金矿的重要标志。

The central-eastern part of the southern Qinghai plateau is situated geologically onBayan Har miogeosynclinal belt,with an average elevation of over 4500m above sea level.It should beascribed to second-order morphologic region composed of plateau mountain basin regions of YellowRiver head and high mountain-valley regions from the middle reaches of Tongtianhe to the upperreaches of Yellow River.Based on discussions of the ore-forming and distributing regularities of the modern placer gold de-posits in the region,and source materials of the placer gold,hydrodynamic state,neoteetonic movementand geomorphie condition,the author points out the important prospecting criteria for the modern placergold deposit in the region.