Recently discovered intermediate-basic volcanic rocks in the Devonian strata at Dachang, Guangxi Zhuang Autonomous Region are dominated by basalts and andesites. Most of them belong to the calc-alkali and alkali serie...Recently discovered intermediate-basic volcanic rocks in the Devonian strata at Dachang, Guangxi Zhuang Autonomous Region are dominated by basalts and andesites. Most of them belong to the calc-alkali and alkali series. Petrology and geochemistry data indicate that the volcanic rocks may be formed in a continental rift environment. The volcanic rocks are in conformable contact with the overlying and underlying wall rocks, with such typical sedimentary structures as laminated and striped ones, and the host rocks of the volcanic rocks contain lots of marine fossils such as tentaculite. Many pieces of evidence indicate that the eruption environment of the volcanic rocks is a sea-facies one. The volcanic rocks are of the LREE-enrichment type, with high ratios of light rare-earth elements to heavy rare-earth elements. In addition, they display moderately negative δEu anomalies and moderately negative δCe anomalies with a higher degree of LREE and HREE fractionation. Through the Q-cluster analysis of the REE samples, it is indicated that the ores have a closer relation with the layered volcanic rocks, and also possess a certain inheritance-consistency relationship with the layered volcanic rocks. The source of ore-forming materials may be related with volcanism. It is proposed that the ore deposit in the study area should be genetically explained as the result of marine volcano-sedimentary exhalation of hot water and late superposition-reworking.展开更多
近年来许多老矿山的保有资源量日趋减少,随着开采的不断深入,保有储量已难维持矿山日常生产,而针对这些矿山的勘探资料充分和数据量大的特点,可以借助G IS的强大的空间分析技术,以计算机为辅助工具,对老矿山的周围和深部进行成矿预测研...近年来许多老矿山的保有资源量日趋减少,随着开采的不断深入,保有储量已难维持矿山日常生产,而针对这些矿山的勘探资料充分和数据量大的特点,可以借助G IS的强大的空间分析技术,以计算机为辅助工具,对老矿山的周围和深部进行成矿预测研究。M APG IS在空间分析方面提供了强大的空间分析模块——DTM分析。笔者以广西大厂锡矿为例,采用M APG IS软件,利用其DTM功能,从建立矿体的矿化强度模型入手,对矿山的周围进行了成矿预测研究。文章认为:运用G IS的空间分析技术进行成矿预测是今后几年内进行成矿预测研究的一个重要发展方向。展开更多
基金financially supported by the Applied Basic Research Projects(General Program)of Yunnan Province(2011FB015)
文摘Recently discovered intermediate-basic volcanic rocks in the Devonian strata at Dachang, Guangxi Zhuang Autonomous Region are dominated by basalts and andesites. Most of them belong to the calc-alkali and alkali series. Petrology and geochemistry data indicate that the volcanic rocks may be formed in a continental rift environment. The volcanic rocks are in conformable contact with the overlying and underlying wall rocks, with such typical sedimentary structures as laminated and striped ones, and the host rocks of the volcanic rocks contain lots of marine fossils such as tentaculite. Many pieces of evidence indicate that the eruption environment of the volcanic rocks is a sea-facies one. The volcanic rocks are of the LREE-enrichment type, with high ratios of light rare-earth elements to heavy rare-earth elements. In addition, they display moderately negative δEu anomalies and moderately negative δCe anomalies with a higher degree of LREE and HREE fractionation. Through the Q-cluster analysis of the REE samples, it is indicated that the ores have a closer relation with the layered volcanic rocks, and also possess a certain inheritance-consistency relationship with the layered volcanic rocks. The source of ore-forming materials may be related with volcanism. It is proposed that the ore deposit in the study area should be genetically explained as the result of marine volcano-sedimentary exhalation of hot water and late superposition-reworking.
文摘近年来许多老矿山的保有资源量日趋减少,随着开采的不断深入,保有储量已难维持矿山日常生产,而针对这些矿山的勘探资料充分和数据量大的特点,可以借助G IS的强大的空间分析技术,以计算机为辅助工具,对老矿山的周围和深部进行成矿预测研究。M APG IS在空间分析方面提供了强大的空间分析模块——DTM分析。笔者以广西大厂锡矿为例,采用M APG IS软件,利用其DTM功能,从建立矿体的矿化强度模型入手,对矿山的周围进行了成矿预测研究。文章认为:运用G IS的空间分析技术进行成矿预测是今后几年内进行成矿预测研究的一个重要发展方向。
