简介:对新疆和静县乔霍特铜矿一带巴音布鲁克组火山岩岩石学、岩石化学、岩石地球化学进行了研究总结,认为该火山岩为钙碱性系列的玄武安山岩-安山岩-英安岩-流纹岩组合,具低TiO2、MgO、高Al2O3,高Fe2O3/FeO比值及富钠贫钾的特点,形成于大洋岛弧环境;在流纹岩中获得(430.33±0.99)Ma的LA-ICP-MS锆石年龄,指示巴音布鲁克组时代为志留纪。
简介:TheShihugolddeposit,situatedintheTaihangMesozoicorogenoftheNorthChinaCraton(NCC),ishostedbyductile-brittlefaultswithinArcheanmetamorphiccorecomplex.Thedepositischaracterizedbygold-bearingquartz-polymetallicsulfidesveins.TheMapenggranitoidsstockandintermediate-basicdikesintrudedthemetamorphicbasementrocks,andarespatiallyrelatedtogoldmineralization.Detailedlaserablationinductivelycoupledplasmamassspectrometry(LAICP-MS)U-Pbzirconagesofthegraniticrocks,dykesandmineralizedquartzveinsinthestudiedarearevealitsmagmaticandmineralizedhistory.Themineralizedquartzveinscontaininheritedzirconswithagesofabout2.55Gaand1.84Ga,probablycomingfromthebasement.ThesetwoPrecambrianeventsarecoevalwiththoseinotherpartsoftheNCC.TheMapenggranitoidstock,thelargestintrusioninthearea,wasemplacedatca.130Ma,andiscoevalwithmagmaticzirconpopulationsfromdioritesandquartzdioritepophyritesinthesameregion.Theca.130MamagmatismandgoldmineralizationweremostlikelyrelatedtoanunderplatingeventthattookplaceintheTaihangorogenatLateMesozoic.Thetimingofgoldmineralizationwithrespecttofelsicmagmatismintheareaissimilartothoseobservedinothermajorgold-producingprovincesintheNCC.ThisepisodeissimultaneouswiththoseintheeasternmarginofNCC,indicativeofawidespreadlateYanshanianmetallogeniceventthatwasaresponsetotheEarlyCretaceouslithosphereintheeasternNCC,inwhichthemesothermalgolddepositswereformedfromsimilartectono-magmaticenvironments.
简介:西准噶尔东部哈拉阿拉特山南麓乌尔禾地区新发现大量中基性岩墙群。岩墙群侵位于下二叠统佳木河组磨拉石建造中,展布方向与达尔布特大断裂延伸方向一致。岩墙群中采集的3个锆石U-Pb年龄样品测年结果分别为(286.3±4)Ma(n=18,MSWD=0.32,95%置信度),(286.5±5.6)Ma(n=10,MSWD=0.3,95%置信度)和(283.6±2)Ma(n=6,MSWD=0.57,95%置信度),误差范围内基本一致,据此确定该岩墙群形成于早二叠乌拉尔世(Cisuralian)亚丁斯克期(Artinskian)。中基性岩墙群具鲜明的与岛弧俯冲作用有关的地化特征,做为西准东部俯冲造山的地质记录,测年结果表明,西准东部的俯冲造山作用明显滞后于西部,整个西准地区俯冲造山作用结束的最终时限为早二叠世晚期。
简介:Themulti-stageintrusionsofintermediate-acidmagmaoccurintheBangpuminingdistrict,thepetrogenicagesofwhichhavebeenidentified.Thetimesandsequencesoftheiremplacementhavebeencollatedandstipulatedindetailinthispaperbyusingthelaserablation-inductivelycoupledplasma-massspectrometry(LA-ICP-MS)zirconU-Pbdatingmethod.Theagesofbiotitemonzogranitethatwereformedbeforemineralizationinthesouthwestofthisminingdistrictare70±1Ma(meansquareofweighteddeviates(MSWD)=9.5,n=8)and60.60±0.31Ma(MSWD=3.8,n=16),whichbelongtothelateCretaceous-earlyPaleoceneinage.Thatmeans,theyareproductsofanearlytectonicmagmaticeventofthecollisionbetweentheIndianandAsiancontinentals.Theagesofore-bearingmonzograniteporphyryandore-bearingdioriteporphyriteare16.23±0.19Ma(MSWD=2.0,n=26)and15.16±0.09Ma(MSWD=3.9,n=5)separately,whichbelongtothemiddleMioceneinage;namely,theyareproductsoftheGangdesepost-collisionextensionalstagewhencrust-mantlematerialsmeltedandmixedaswellasmagmaticintrusionsimultaneouslyoccurred.Somezirconswithagesof203.6±2.2Ma(MSWD=1.18,n=7)werecapturedintheore-bearingdioriteporphyrite,whichshowsthattherehadbeentectono-magmaticeventsinthelateTriassic-earlyJurassic.Molybdenum(copper)ore-bodiesproducedinthemonzograniteporphyryandcopper(molybdenum)ore-bodiesproducedinthedioriteporphyritearethemainoretypesinthisoredeposit.ThemodelagesofRe-Osisotopicdatingforthe11molybdeniteare13.97-15.84Ma,whileisochronagesare14.09±0.49Ma(MSWD=26).Theisochronagesofsevenmolybdenitefrommolybdenum(copper)orewithmonzograniteporphyrytypeare14.11±0.31Ma(MSWD=5.2).Thereisgreaterrorintheisochronagesoffourmolybdenitefromcopper(molybdenum)orewithdioriteporphyritetype,andtheirweightedaveragemodelagesof14.6±1.2Ma(MSWD=41),whichgenerallyrepresentthemineralizationage.TheresultsabouttheR
简介:土地潜力定性与定量分析,是土地开发利用整理的重要指标。本文以阜新市伊吗图镇采煤沉陷区土地整理项目为例,论述了应用组件式GIs—superMapGIs建立土地开发整理潜力分区信息系统的方法。该方法革新了传统的手工方法,提高了工作效率和质量。
简介:在研究唐山市地质环境状况的基础上,基于GIS技术建立了唐山市区地质数据库,并利用编程语言VB和GIS组件MapObjects开发地质数据管理系统,实现了地质数据的存储、显示、查询、分析及更新维护,为唐山城市规划与工程建设提供可靠的决策支持.
简介:从典型矿床点分析大庙山含金角砾岩工业矿体的控矿条件及找矿方向