地学前缘 ›› 2012, Vol. 19 ›› Issue (3): 84-92.

• 论文 • 上一篇    下一篇

长江中下游地区不同尺度铜地球化学异常的意义

徐善法,王玮   

  1. 1. 中国地质科学院 地球物理地球化学勘查研究所, 河北 廊坊 065000 2. 中国地质科学院 应用地球化学重点开放实验室, 河北 廊坊 065000
  • 收稿日期:2012-04-10 修回日期:2012-04-20 出版日期:2012-05-25 发布日期:2012-05-25
  • 作者简介:徐善法(1963—),男,教授级高级工程师,应用地球化学专业。E-mail:xushanfa@igge.cn
  • 基金资助:

    国土资源部行业专项“深部探测技术与实验研究”第四项目第三课题(SinoProbe-04-03)

The significance of different scale copper geochemical anomalies and large ore deposit prediction in the middlelower Yangtze River.

  1. 1. Institute of Geophysical and Geochemical Exploration, Chinese Academy of Geological Sciences, Langfang 065000, China 2. Key Laboratory of Applied Geochemistry, Chinese Academy of Geological Sciences, Langfang 065000, China
  • Received:2012-04-10 Revised:2012-04-20 Online:2012-05-25 Published:2012-05-25

摘要:

以长江中下游1∶20万铜区域地球化学数据为基础,研究了铜元素地球化学异常特征,认为不同尺度的地球化学异常图具有不同的研究意义:(1)1∶20万地球化学异常可以圈定矿床异常,用于大型矿床预测。研究区内13个大型矿床中有12个落在具有三层套合结构的地球化学异常中,已知矿床储量与异常面金属量、异常面积之间的相关系数分别为0.94、0.95,显示区域地球化学异常规模与储量之间的较好相关性。(2)1∶50万地球化学异常可以圈定矿区异常,用于在成矿带中预测有利成矿区。(3)1∶100万地球化学异常可以圈定大型矿集区或成矿带,用于矿集区预测。如果把研究区内面积大于1 000 km2且含有3个以上已知矿床的异常作为矿集区的话,则长江中下游存在3个大型矿集区:马鞍山—南京矿集区、九江—瑞昌—大冶矿集区和德兴—黄山—安庆—铜陵矿集区(实际上包含德兴和铜陵2个矿集区)。大型矿床多产于多层套合的地球化学异常中,大型矿集区所形成的异常具有至少3层套合结构,浓集中心与大型矿床存在对应关系,这些规律的发现为在不同成矿域预测新的大型矿集区提供了重要地球化学标志。

关键词: 长江中下游, 地球化学异常, 预测, 铜元素

Abstract:

Based on the 1∶200000 regional geochemical data of copper element as the foundation in the middlelower Yangtze River, the different scales of geochemical anomaly map can be used for different purposes. (1)The 1∶200000 geochemical anomalies can be used for outlining anomalous target area of a deposit and forecasting large deposits. Twelve of 13 large deposits fell in threetier structure of geochemical anomalies in the study area; the correlation coefficient between the ore reserves of known deposits and areal productivity of geochemical anomalies is 0.94; the correlation coefficient of known deposit reserves and geochemical anomalous areas is 0.95, showing a good correlation between the size of ore reserve and the scale of regional geochemical anomalies. (2)The 1∶500000 geochemical anomalies can be used to delineate anomalous target areas of an orefield, to predict the favorable mining area in a metallogenic belt. (3)The 1∶1000000 geochemical anomalies can be used to delineate a large ore district or a metallogenic belt target for ore district prediction. If we consider an area greater than 1000 km2 including three deposits as an ore district, then, there are three large ore districts in the middlelower Yangtze River: Maanshan  Nanjing ore district, Jiujiang  Ruichang  Daye ore district and Dexing  Huangshan Anqing  Tongling ore district (actually containing two Dexing and Tongling ore districts). Large deposits often occurred in the areas with multilayered geochemical anomalies, and the geochemical anomaly in a large ore district has at least a 3 layered structure; there exists a corresponding correlation between the concentration centers and the large deposits. The discovery of these laws provides an important geochemical marker for predicting new large ore district in different mineralization areas.

Key words:  the middlelower Yangtze River, geochemical anomalies, prediction, copper element

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