摘要
岩浆岩地球化学数据作为地质学研究的重要依据,对于指示元素特征、研究成矿规律至关重要。该文以构建的长江中下游成矿带岩浆岩地球化学数据库为基础,以岩浆岩成矿3个地质时期及其成矿岩体的地理空间分布特征为依据,利用GIS的Ripley′s K函数对不同时期成矿岩体的空间格局进行多距离空间聚类分析,获取成矿岩体的空间聚集尺度,进而利用GIS的核密度分析工具求取3个地质时期的成矿核心及其时空演化特征,并以控矿元素Cu、Au为例展开空间分析,进一步揭示成矿核心区对于成矿预测及科学找矿的重要意义。研究结果表明:1)长江中下游成矿带安徽段3个成矿时期(124~148 Ma)的岩浆岩成矿核心呈动态变化,形成一强多弱相结合的成矿核心空间分布格局,空间上成矿核心由铜陵、安庆—贵池矿集区向庐枞、宁芜盆地方向扩展,时间上成矿聚集程度逐渐变弱;2)以铜金成矿为主的第一时期,铜金等成矿岩体及其形成的重要多金属矿床受长江深断裂构造控制,安徽段主要集中于长江深断裂以南4~28 km处的铜陵、安庆—贵池等断隆区,其Cu、Au含量高值位于成矿核心东、西两侧的扇形带上,该区域是铜金等多金属矿床找矿的有利地段。
As an essential basis of geological research,the geochemical data of magmatite play an important role in indicating geochemical element characteristics and studying metallogenic regularities.In this paper,based on the geochemical database of the metallogenic belt in the middle and lower reaches of the Yangtze River,the spatial aggregation scales of magmatic mineralization in three geological periods were analyzed by using Ripley′s K function of GIS,and the cores of mineralization and their spatial-temporal evolutionary characteristics in three geological periods were obtained by using the kernel density analysis tool of GIS.And then,take the ore controlling elements,Cu and Au as examples,the vital significance of the core area of magmatic mineralization to metallogenic prediction and scientific exploration was proved.The results show that:1)The metallogenic cores of magmatic rocks changed dynamically in three metallogenic stages(124~148 Ma),and a spatial distribution pattern with a strong core and multiple weak cores was formed,which extended from the ore concentration districts of Tongling and Anqing-Guichi to the basins of Lu-Zong and Ning-Wu.In terms of time,the clustering degree of minerlization weakened gradually.2)The valuable polymetallic deposits of Anhui province formed in the first stage were concentrated in the fault-uplifted areas about 4 to 28 km to the south of the Yangtze River fault.And the enrichment areas of Cu and Au were located at the fan belt on the east and west sides of the ore-forming cores,which were the favourable areas for exploring polymetallic deposits of Cu,Au,etc.
作者
汪婷婷
陈国旭
袁峰
张明明
李晓晖
赵萍
WANG Ting-ting;CHEN Guo-xu;YUAN Feng;ZHANG Ming-ming;LI Xiao-hui;ZHAO Ping(School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009;Anhui Province Engineering Research Center for Mineral Resources and Mine Environments,Hefei 230009;Ore Deposit and Exploration Centre,Hefei University of Technology,Hefei 230009,China)
出处
《地理与地理信息科学》
CSCD
北大核心
2020年第4期19-25,共7页
Geography and Geo-Information Science
基金
国家自然科学基金项目(41972304、41402289)。
关键词
岩石地球化学数据库
多距离空间聚类分析
核密度分析
成矿核心区
时空聚集特征
geochemical database of rocks
multi-distance spatial cluster analysis
kernel density analysis
metallogenic cores
spatial-temporal aggregation characteristics
作者简介
汪婷婷(1993-),女,硕士研究生,主要从事GIS在地质学及资源勘查方面的应用研究;通讯作者:陈国旭,E-mail:chenguoxu1983@163.com。
