简介:Byusingthe40Ar-39ArchronologicalmethodtodateK-feldsparfromK-feldspargraniteintheQiaohuotecopperdistrict,theauthorsobtainedaplateauageof274.78±0.44Maandanisochronageof272.7±3.0Ma.BecausethereisnotectonicdeformationoverprintedorhydrothermalalterationintheK-feldspargraniteintrusionafteritsemplacement,the40Ar-39AragerepresentsthecrystallizationageofK-feldsparinK-feldspargranite,i.e.thelatecrystallizationageoftheK-feldspargraniteintrusion,whichindicatesthattheK-feldspargraniteformedintheintraplateextensionalstageduringtheEarlyPermian.Moreover,basedonthespatialrelationshipbetweentheK-feldspargraniteintrusionandcopperorebodies,variationsofcopperoregrade,REEcharacteristicsofK-feldspargraniteandcopperores,andHandOisotopiccompositionsoffluidinclusionsincopperores,themetallogenesisoftheQiaohuotecopperdepositisdirectlyrelatedtointrusiveactivitiesoftheK-feldspargranite,andthusthecrystallizationageofK-feldsparinthegraniteapproximatelyapproachesthemetallogenicepochoftheQiaohuotecopperdeposit.
简介:<正>1IntroductionTheundergroundbrineresourcesdistributingwidelyinSichuanBasin,Chinahavedrawnworldwideattentionduetotheirunusualelementabundanceandexcellentquality.
简介:在地热能源不断得到关注和利用的当今社会,对其科学合理地开发利用显得尤为重要.文章采用层次分析法和多目标决策的线性加权相结合的方法建立了地热水开发利用前景评价模型,避免了以往单纯从定性角度分析地热水开发利用前景的人为主观性及片面性,保证了评价结果的客观准确,经实例验证,是一种行之有效的评价方法.作者选取地热地质条件、经济发展水平、开发利用现状作为层次分析法的中间层要素,进而将其进一步分解为不同的组成因素,运用层次分析法计算出各项指标的权重,结合多目标决策的线性加权方法建立综合评价评分的数学模型,最后根据地热田的实际情况,综合评价,确定评价结果.
简介:ThisstudyreportszirconU-PbandHfisotopesandwhole-rockelementaldataforgranodioritesfromtheEastKunlunorogen.ThezirconU-Pbdatingdefinestheircrystallizationageof235Ma.Therocksarecharacterizedbyhigh-Kcalc-alkaline,magnesianandmetaluminouswith(K2O+Na2O)=6.38wt.%–7.01wt.%,Mg#=42–50[Mg#=100×molarMg/(Mg+FeOT)],A/CNK=0.92–0.98,coupledwithhighεHf(t)valuesfrom-0.65to-1.80.Therockswerederivedfrompartialmeltingofajuvenilemaficcrustalsourcewithinnormalcrustthickness.Thejuvenilelowercrustwasgeneratedbymixinglithosphericmantle-derivedmelt(55%–60%)andsupracrustalmelt(40%–45%)duringtheseafloorsubduction.TogetherwithavailabledatafromtheEastKunlun,itisproposedthatthestudiedMiddleTriassicgranodioriteswereformedinpost-collisionalextensionsetting,inwhichmeltingofthejuvenilelowercrustinresponsetothebasalticmagmaunderplatingresultedintheproductionofhigh-Kgranodioriticmelts.
简介:灰色系统理论GM(1,1)模型,应用于地面沉降模拟和预测中只能分析数据的指数变化规律。对于地面沉降发展过程中,存在的线性关系不能有效地反映。本文利用灰色组合模型中的第一类灰色组合模型即GM(1,1)与线性回归模型相融合。选取北京东部某地面沉降监测站2004-2012年的分层监测数据建立模型,计算出各监测层位沉降的数学模型,并以此预测各监测层位地面沉降量。结果表明:利用灰色线性回归组合模型在对地面沉降进行分层模拟和预测是可行的。在已有数据的基础上,利用数学模型进行沉降模拟时,两种模型的精度均很高,但通过模型预测未来一年沉降量时,灰色线性回归组合模型的精度,要远高于普通均值GM(1,1)模型。