应用GIS浅析冀北地区太古界变质岩与金矿的关系
2016-12-01刘文建杨超陈亚伟刘文
刘文建 杨超 陈亚伟 刘文



摘要:冀北地区处在西伯利亚板块与华北板块之间,受到地质运动的多期强烈改造,具有极为有利的金成矿地质条件,成矿事实及找矿标志也极为显著。目前在冀北地区发现的绝大多数金矿均产于太古界变质岩内,表明两者在空间上紧密相关,通过成矿广度和成矿强度的GIS理论分析,进一步证明了冀北地区金矿与太古界变质岩之间关系密切。
关键词:成矿广度;成矿强度;变质岩;金矿床
APPLICATION OF GIS TO THE SUPERFICIAL ANALYSIS OF THE RELATIONSHIP BETWEEN ARCHAEOZOIC METAMORpHIC ROCKS AND GOLD MINERALIZATION OF NORTH AREA OF HEBEI PROVINCE
Liu Wen-jian,Yang Chao and Chen Ya-wei
Xi an Institute of Geology and Mineral Development,Xi an 710054
Abstract:North area of Hebei province,lying between Siberia plate and North China plate,is an active belt in the geological evolution history,has suffered much extensive reformation of multi-term geological movement. So the study area has a very favorable geological conditions for forming gold deposits. According to statistics,the majority of gold deposits found in the area are hosted in Archaeozoic metamorphic rocks,indicating the closed relationship in space between them. And also by means of ore-forming intensity and extensity,the closed relationship between Archaeozoic metamorphic rocks and gold deposits in the area is further proved.
Key words: ore-forming intensity;ore-forming extensity;metamorphic rock;gold deposit
引言
冀北系指东经114°~119°,北纬40°~42°之间的地区,主要包括张家口市和承德市。冀北地区在地质演化史上是一个构造岩浆作用异常强烈的活动带,具有十分有利的成矿地质背景。目前,冀北地区已知金矿产地和矿点约233个,其中超大型金矿床1处,大型金矿床2处,中型金矿床10处,小型金矿27处。这些矿床(点)绝大部分产于太古界变质岩内,两者在空间上紧密相关。本文将应用GIS——“成矿广度与成矿强度”理论定量分析两者之间的关系。
1. 成矿广度和成矿强度
“成矿广度和成矿强度”理论主要用于评价研究区的成矿有力度,由池顺都教授所提出,其中,“成矿广度”代表工作区范围内矿化发育的广泛程度,用区域内产出的资源量多少来表示。“成矿强度”代表矿化发育的强烈程度,用在某成矿单元面积(出露的地层)所拥有的矿产资源量来表征。
考虑到矿产地的规模不尽相同,成矿广度通过矿产当量N来衡量:
N=N1×K1+N2×K2+N3×K3+N4
其中:N1、N2、N3、N4分别代表大、中、小型矿床和矿点的个数。……
