西藏冈底斯多金属成矿带斑岩铜矿定位预测与资源潜力评价

自1999年开展地质大调查以来,冈底斯成矿带斑岩铜矿研究取得了重大进展.本文在全面收集冈底斯成矿带地质、矿产和物化探资料基础上,建立了本区GIS平台上的资源预测评价系统.采用数理统计分析,确定了冈底斯成矿带斑岩铜矿定位预测的定量化标志35个,认为对斑岩铜矿预测影响比较重要的地质变量(因素权重>0.2)为花岗岩体(不限时代)、Cu、Mo、W、Au、Ag、Bi化探异常、Cu-Mo、Cu-Mo-Au、Cu-Au-Ag组合化探异常、矿床规模、重力场中低负异常场等.在此基础上,开展了工作区斑岩铜矿的定位预测,圈定了斑岩铜矿成矿远景区33处,计算结果与实际矿产分布和地质理论分析相吻合.采用面金属量法对冈底斯成矿带斑岩铜矿的资源潜力进行了估算,结果表明,冈底斯地区仍具有良好的斑岩铜矿找矿远景,1 000 m以浅的潜在铜资源量可达1亿吨以上.其中,驱龙-甲马-拉抗俄、松多雄、白容-冲江、松多握、吉如、达布、汤不拉、龙卡朗、崩不弄金矿、洞嘎、雄村、麦热-仁钦则、蒙哑啊东北、吹败子、岗达、沙让-亚贵拉、青龙-龙马拉、冲木达、洛麦南、拉屋找矿潜力较大.

Regional metallogenic prognosis and mineral reserves estimation for porphyry copper deposits in Gangdese polymetallic ore belt, Tibet

The search for porphyry copper deposits in the Gangdese metallog enic belt has made great advance since the beginning of the geological survey pr oject. Based on a complete acquisition of geological, ore deposit, geophysical a nd geochemical data, the authors established a mineral resources evaluation syst em based on GIS technology. 35 geological factors for the prognosis of porphyry copper deposits were determined by means of mathematic statistics. The most impo rtant geological factors for porphyry copper prognosis include granite, Cu, Mo, W, Au, Ag, Bi geochemical anomalies, composite Cu-Mo, Cu-Mo-Au, Cu-Au-Ag geochem ical anomalies, size of the discovered ore deposit and middle-low negative gravi ty anomalies. According to the calculation of the MRAS system, 33 target areas f or porphyry copper deposits were delineated in the Gangdese metalloge nic belt. Th e result of the statistical method is in accordance well with the geological ded uction. The copper reserves were estimated by the areal productivity method, whi ch shows that there still exists a great potential of porphyry copper deposits in Gangdese and that the predicated copper reserves are over 100 million tons. The potential target areas for porphyry copper deposits include Qulong-Jiama-Lankange, Songdu oxiong, Bairong-Chongjiang, Songduowo, Jiru, Dabu, Tangbula, Youkalang, Pengbuno ng, Dongga, Xiongchun, Maire-Renqingze, Mengyaa, Cuibaizi, Gangda, Sharang-Yagui la, Winglong-Nongmala, Chongmuda, Luomainan and Lawo.