中国矽卡岩矿床找矿新进展和时空分布规律

摘要

In the past decade,notable progress has been made in the discovery and exploration for skarn deposits in China.The discovery and exploration of ore deposits include more than 10 large Cu-(Au)-polymetallic skarn deposits in the Gangdise ore belt,Bangong-Nujiang ore belt,Tibet;many Fe polymetallic skarn deposits in the Qimantag ore belt,Qinghai;some large concealed skarn deposits in eastern China,such as Baijian iron deposit in Hebei Province,Zhuxi W-polymetallic deposit in Jiangxi Province,Xitian W-Sn deposit in Hunan Province,and Shangfang tungsten deposit in Fujian Province;some large iron skarn deposits related to marine volcano-intrusive activity in western Tianshan Mountains of Xinjiang.In addition,the Baiganhu,Shadong and Taergou large tungsten skarn deposits of Xinjiang and Gansu have also been discovered and explored.A lot of new isotopic chronologic data of the main skarn deposits in China suggest that the metallogenic ages include Proterozoic,Palaeozoic,Mesozoic,and Cenozoic.Among them,the most important is Mesozoic Yenshanian ages.As forspatial distribution of skarn deposits,Zhao et al.,(1990) divided the mineralization into 14 metallogenic belts,with the majority distributed in the activated region of the North China Craton and orogenic belts in East China,which constitute a part of the Circum-Pacific metallogenic belt.Owing to the effort of Chinese geologists,the exploration for skarn deposits in the Tibet,Qinghai,and Xinjiang has achieved remarkable success,which results in the addition of four ore-skarn belts:i.e.,Gandise ore belt,Bangong-Nujiang ore belt in Tibet,Qimantag ore belt in Qinghai,and Western Tianshan ore belt in Xinjiang.%近年来,中国矽卡岩矿床找矿取得了很大的新进展:西藏冈底斯成矿带和班公湖-怒江成矿带发现和探明了十余个大中型矽卡岩铜、金多金属矿床;在青海西部祁漫塔格成矿带发现和探明了不少铁多金属矽卡岩矿床;在东部地区发现和探明了一批大型隐伏的矽卡岩矿床,如河北白涧铁矿床、江西朱溪钨多金属矿床、湖南锡田锡钨矿床、福建上房钨矿床等.在新疆西天山发现和探明了一批大(中)型与火山-侵入活动有关的矽卡岩铁矿床.另外,在新疆发现白干湖、沙沟等大型钨矿床,在甘肃也发现和探明了大型钨矿床.学者们对上述矿床进行了较详细的研究.中国主要矽卡岩矿床最新同位素测年资料表明,矽卡岩矿床的生成时代从元古宙、古生代、中生代到新生代都有,但最重要的成岩成矿期是中生代的燕山期.在空间分布上,赵一鸣等(1990)曾划分出14个重要的矽卡岩成矿带,通过广大地质工作者的努力,在西藏、新疆和青海等省(区)找矿工作的重大进展,又新增4个矽卡岩成矿带,即西藏冈底斯成矿带、班公湖-怒江成矿带、青海祁漫塔格成矿带和新疆西天山成矿带.