地面伽玛能谱的应用与成果野外工作方法及技术措施

地面伽玛能谱的应用与成果野外工作方法及技术措施 地面伽玛能谱的应用与成果野外工作方法及技术措施 地面伽玛能谱的应用与成果野外工作方法及技术措施 地面伽玛能谱的应用与成果野外工作方法及技术措施 地面伽玛能谱的应用与成果野外工作方法及技术措施众所周知，镭具有较强的活动性，因此它容易形成范围很广的次生分散晕。疏松层中的镭分散晕，往往是覆土下的基岩铀矿化的一个重要标志。当镭的含量很高时，分散晕容易为伽玛总量测量所发现。由于伽玛总量测量测得的射线强度不只与镭含量的多少有关，而且还与别的放射性元素（如钍、钾）变化有关，因此其异常/干扰比值较小。伽玛能谱测量则能消除上述缺点，从而提高来异常 /干扰比值。Aseveryoneknows,radiumhasstrongeractivity,soitiseasytoformawiderangeofsecondarydispersionhalo.Thelooselayerofradiumdispersionhalo,isoftenanimportantsymbolofthebedrockofuraniummineralizationinsoilunderthe.Whentheradiumcontentisveryhigh,dispersionhaloeasilyfoundbyGamagrossmeasurement.Becausetherayintensitygammatotalmeasurementmeasurednotonlywiththeradiumcontentrelatedtohowmuch,butalsowithotherradioactiveelements(suchasthorium,potassium)change,thereforetheabnormal/interfereneeratio.Gammaenergyspectrummeasurementcaneliminatethedisadvantages,soastoimprovetheunusual/interfereneeratio.测区位于xx火山盆地。自I960年以来先后有华东608队、中南309队、华南292队开展了大量的伽玛、径迹普查、详查等工作，其中包括不同比例尺的综合方法详查、水化普查、放射性地质测量、地表揭露等。发现了5103矿床,并在深部揭露评价了矿区南部的矿化点，矿区以北的五里桥 3104矿化点。为了扩大找矿范围，对该区进行了1：2000地面伽玛能谱测量，取得了一定的成果。LocatedattheXXvolcanobasinarea.Since1960therehavebeen608teams,SouthEast309teams,292teamsinSouthernChinacarriedoutalargenumberofgamma,tracksurvey,reconnaissaneework,detailed,comprehensivemethodsincludingdifferentscalehydrationcensus,radioactivegeologymeasurement,surfaceexposure.Found5103deposit,andexposetheevaluationofmineralizationinthedeepsouthernminingarea,miningareanorthoffivemilebridge3104mineralization.Inordertoexpandtheprospectingscope,ontheareaofthe1:2000groundgammaenergyspectrum,andachievedcertainresults.工作区地质及地球物理特征Geologicalandgeophysicalcharacteristics1.1地质特征geologicalfeatures

矿区位于盆地南缘。区内中生代以来，岩浆活动频繁，早期大规模花岗岩侵入，形成了该盆地东部的大神坝花岗岩岩体及盆地西部的桂坑花岗岩体， 到晚白垩世末期火山活动已近尾声，大量的酸性火山物质携带着丰富的铀铣络合物涌上地表或近地表浅处，在后来的结晶、 脱玻过程中使一部分活动的铀活化出来， 成为成矿物质的重要来源，同时火山热液也为铀的聚集创造了良好的条件。Mineislocatedinthesouthernmarginofthebasin.SineetheMesozoic,frequentmagmaticactivities,earlymassivegraniteintrusion,formedaGUIKenggranitebodyofthebasintotheeastofthewesternrockgoddamgraniteandbasin,toattheendofthelateCretaceousvolcanoactivityisneartheend,alargenumberofsubstancesacidicvolcanowithuranylcomplexesabundantChungonornearthesurfaceofshallowoffice,laterinthecrystal,thedevitrificationprocessthatapartofactiveuraniummobilization,becomeanimportantsourceofmetallogenicmaterials,atthesametimevolcanohydrothermaluraniumaccumulationtocreategoodconditions.地层较为简单，主要有寒武系一泥盆石炭系地层、白垩系上统叶塘组地层。Theformationofrelativelysimple,mainlyofCambrian,DevonianCarboniferousseriesleafpondformation,Cretaceousstrata.寒武系（€）—泥盆石炭系（D—C）:分布于南部和东南部，为一套复理式碎屑建造。岩性为青灰色砂质板岩、千枚岩、变质砂岩、绢云母片岩等。TheCambrian(c)-DevonianandCarboniferous(D-C):locatedintheSouthandSoutheast,isasetofflyschclasticrocks.Thelithologyisgreysandyslate,phyllite,metamorphicsandstone,sericiteschist.白垩系上统叶塘组(K2)分为下、中、上三组：UpperCretaceousleafTongGroup(K2)weredividedintothreegroups,:下组（K21）为黑色玄武岩；中组（K22）上部为紫红色砾岩、砂砾岩、砂岩、粉砂岩；下部为紫红色砾岩；上组（K23）为一套陆相酸性喷发岩，在该区大面积分布，岩性主要为流纹质火山碎屑岩和熔岩。中上组顶部为矿床主要含矿岩系。Thegroup(K21)isablackbasaltgroup(K22);theredbreccia,conglomerate,sandstone,siltstone;thelowerpartispurplishredconglomerate;group(K23)isasetofcontinentalacideruptiverocks,inlargeareadistributioninthisarea,thelithologyismainlycomposedofrhyoliticvolcanoclasticrocksandlava.Inthegroupoftopdepositmainore-bearingrockseries.白垩系上统叶塘组(K2)主要出露在矿区北部，不整合复盖在菖蒲群之上，为一套内陆河湖相沉积的磨拉石建造。岩性主要为紫红色砂砾岩、砂岩、 浅色粉砂岩。

UpperCretaceousleafTongGroup(K2)ismainlyexposedinthenorthernminingarea,unconformabilityinChangpugroup,molasseformationisasetofinlandlakefacies.Themainlithologyispurplishredsandyconglomerate,sandstone,siltstone,light.矿床构造主要有陡倾层间硅化破碎带（F15）和NWW向两组构造。F15层间硅化破碎带，是矿床主要控矿、含矿构造。处于麻楼断裂带北侧，沿含砾晶屑熔结凝灰岩和含砾凝灰岩界面发育。走向 260〜280°倾向350〜200°，倾角60〜75°长4.5km，宽0.2〜2m，西段最宽8m。舒缓波状，物质成份主要由硅化凝灰岩、含砾凝灰岩、角砾岩、糜棱岩、裂隙破碎岩带等组成。热液活动深部显示较强，地表微弱。主要表现为硅化、赤铁矿化、含铀炭质物，显示与铀矿化的密切关系。Thestructureofthedepositsaremainlysteepinterlayersilicifiedfracturezone(F15)andNWWtothetwogroupstructure.F15interlayersilicifiedfracturedzone,isthemainore-controlling,ore-bearingstructure.Inthenorthofhempfloorfracturezone,developmentalongthegravelcrystalignimbriteandtuffgravelinterface.Trend260~280 tendencyin350~200 ,theangle60〜75°,long4.5km,width0.2~2m,widthofthe8m.Slowwaveshape,materialcompositionismainlycomposedofsilicifiedtuff,lapillituff,breccia,mylonite,fracturerockbeltetc..Hydrothermalactivitydeepshowedstrongweak,surface.Mainlyforthesilicification,hematitization,uraniumcontainingcarbonmatter,showsacloserelationshipwithuraniummineralization.1.2地球物理特征oftheearth'sphysicalcharacteristics区内放射性元素在各地层中分布具有明显差异。 铀含量从新到老，从上到下的变化趋势如表1，古近系铀含量最低，寒武系钍含量最低，紫红色晶屑熔接凝灰岩钾最低，大片地段为零。据矿床铀镭平衡系数测定，地表稍偏镭，整个矿床平衡，且变化较小，为测区开展放射性物探工作提供了良好的条件。 水中铀含量及氡浓度都较低，铀一般为10X10-7克/升，氡约72.9Bq/升，水质类型为SiO2-H-N型为主。Radioactiveelementswithintheareadistributionhasobviousdiffereneeineachlayerinthe.Uraniumcontentfromthenewtotheold,fromthetrendtothenextastable1,Paleogeneuraniumcontentwasthelowest,theCambrianthoriumcontentwasthelowest,purplecrystalfusedtuffpotassiumminimum,largeareaiszero.AccordingtothedeterminationofdepositU-Raequilibriumcoefficient,thesurfaceslightlyradium,thedepositbalanee,andthechangeissmall,measuringtheradioactivegeophysicalprospectingworkhasprovidedgoodconditions.Thecontentofuraniumandradonconcentrationinwaterarelow,uraniumis10 10Xg/L,radonisabout72.9Bq/litersofwaterquality,typeSiO2-H-N.地面伽玛能谱的应用与成果Applicationandresultsof2groundgamma-rayspectrum2.1野外工作方法及技术措施2.1fieldworkmethodsandtechnicalmeasures1:2000伽玛能谱测量，采用规则测网,用高精度GPS测量仪布置基线，测线距为20m，误差不超过0.1米。测线长不超过1000m，测线用地质罗盘定方位,点距为10m，用2m木杆丈量，每100m误差不超过2m。基线基本平行主要控矿构造和岩层走向。测网精度均达到规范要求。测网覆盖整个测区的多种岩性,矿体，构造以及断裂带。1:2000gammaspectrummeasurement,usingtheregularsurveygrid,usinghighprecisionGPSmeterisarrangedatbaseline,linespacingis20m,theerrorisnotmorethan0.1meters.Totallengthisnotmorethan1000m,linewithgeologicalcompassorientation,distaneeis10m,2mwoodmeasurement,theerrorislessthan2mper100m.Baselinesubstantiallyparalleltothemainore-controllingstructureandstrike.Measurementprecisionreachedthestandardrequirements.Monitoringnetworkcoveringthewholeareaofthelithology,orebody,structureandfracturezone.2.2异常特征及推断anomaliesandinferenee从图中圈出的偏高场分布来看，总量偏高场共划分7个，编号分别为刀1〜7号，铀偏高场、高场共划分20个晕圈片或晕圈带，编号分别为U1〜20。其中U1〜5号是位于5103矿场西段500m的F15和上增断裂交汇部分；U6〜9号偏高场位于上增断裂西北和磷石下断裂附近； U10〜13号位于测区磷石下断裂西北。U14〜17号位于F15带附近；U18〜20号位于麻地坑处。基本组成三个铀远景片。I级远景片由2、4号偏高场组成。U级远景片由5、7、14、16偏高场组成；III级远景片由1、3、6、8、9、10、11、12、13、15、17、18、19、20组成。Fromthepointofviewofdrawingcirclehighfielddistribution,thetotalisdividedinto7,numbered 艺1~7,higheruraniumfield,highfieldisdividedinto20haloorhalozone,numberedU1~20.U1~5islocatedonthe5103fieldof500mF15andincreasedfractureintersectionpart;fracturenearU6~9islocatedonthenorthwestandphosphorusincreasedfractureunderthestone;U10~13islocatedinthenorthwestareaofphosphorusundertherockfracture.U14~17intheF15zone;U18~20mApitlocatedat.Thebasiccompositionofthreeuraniumprospectstablets.Compositionofvisionby2,No.

4highfield.IIvisionchipconsistsof5,7,14,16highfield;IIIvisioniscomposedof1,3,6,8,9,10,11,12,13,15,17,18,19,20.图1工作区铀异常及总量异常分布图AnomalydistributionmapFigure1workareaandthetotaluraniumanomalyI级远景片由2、4号偏高场组成。Compositionofvisionby2,No.4highfield.2号U偏高场位于F15带上，产于含砾凝灰岩和晶屑熔接凝灰岩的接触界面附近。U含量一般7〜16.4ppm,最高含量达21.8ppm。偏高场呈东西展布，长420m,宽20m〜150m，场值较高。通过实地检查，为5103矿床矿化引起，有较好的找矿意义，可进一步扩边探深扩大远景地段。UhighfieldislocatedintheF15zone,neartotuffandtuffgravelchipweldinginterface.Ucontentisgenerally7~16.4ppm,thehighestcontentofupto21.8ppm.Highfieldineast-westdistribution,long420m,wide20m~150m,fieldvaluesofhigher.Throughon-the-spotinspection,duetothe5103mineralization,havegoodprospectingsignificanee,furtherexpansionofsoundingexpandprospectarea.4号位于大塘肚北面和5103矿床南侧，产于次流纹斑岩（入n）花岗斑岩（丫冗）的上盘。高场值连续性较好，晕圈呈东西向，长 220m，宽80m〜130m。U含量一般8〜12ppm,局部最高达27.7ppm。前人在此进行过钻探浅部探索，见有蓝矿化，可进一步扩边探深寻找深部矿化扩大远景。No.4islocatedinNorthandSouthTong5103deposit,producedinthesecondaryrhyoliteporphyry(lambdaPI)andgranite( 丫冗)ofthehangingwall.Highfieldvaluebettercontinuity,halowaseast-west,long220m,wide80m-130m.Ucontentisgenerally8~12ppm,thelocalhighupto27.7ppm.Thepredecessorinthistooshallowdrillingexploration,seebluemineralization,furtherexpansionofdeepinsearchofdeepmineralizationprospectextension.U级远景片由5、7、14、16号4个U偏高场组成。visionchipconsistsof5,7,14,16,4Uhighfield.5号位于上增断裂带东侧，产于紫红色晶屑熔接凝灰岩 （K23C-2）中，附近有一个800丫的异常点。U含量一般7〜9ppm，长340m，宽40m〜140m，连续性较好，晕圈呈北东向。上增断裂为成矿有利地段，有一定的找矿意义，可进行深部探索。No.5islocatedintheeastofafaultzone,producedinthepurplecrystalweldedtuff(K23c-2),abnormalpointofa800gammanear.Ucontentis

generally7~9ppm,length340m,width40m~140m,goodcontinuity,halone-trending.Afaultisthemineralizationfavorableareas,hasacertainsignificaneeinprospectingfordeepexploration.7号位于磷石下断裂下盘，产于紫红色晶屑熔接凝灰岩（K23C-2）和含砾凝灰岩。U含量一般7〜9ppm，长190m，宽70m〜100m，连续性较好，晕圈呈北东向。受磷石下断裂控制，有一定的找矿意义。No.7inphosphorusrockunderthefootwall,producedinthepurplecrystalweldedtuff（K23c-2）andpebbledtuff.Ucontentisgenerally7~9ppm,length190m,width70m~100m,goodcontinuity,halone-trending.Thephosphaterockfracturecontrol,haveacertainsignificaneetooreprospecting.14号位于F15带南侧，处于细花岗岩（丫52岩性中，受中基性岩脉与磷石下断裂和花岗斑岩（Yn）向。U含量一般7〜15ppm。长150m,宽80m〜100m。连续性好，成矿有利。对找矿有意义。No.14islocatedinthesouthoftheF15band,infinegranite（ 丫52）lithology,themaficdikesandphosphorusrockfractureandporphyrygranite（ 丫冗）effect.ThecontentofUis7~15ppm.Long150m,wide80m-100m.Goodcontinuity,mineralization.Thereissignificancetooreprospecting.16号位于F15带附近，产于含砾凝灰岩（K23a-7）中。U含量一般7ppm〜10.8ppm，长250m，宽50m〜160m。可能受F15影响，成矿性大，对地质找矿意义较大。值得继续工作。No.16islocatedintheF15zone,producedinthegraveltuff（K23a-7）.Ucontentingeneral7ppm~10.8ppm,length250m,width50m~160m.MaybeaffectedbyF15,mineralization,thegeologicalprospectingsignificance.Tocontinuetowork.级远景片由1、3、6、8、9、10、11、12、13、15、17、18、19、20组成。IIIvisioniscomposedof1,3,6,8,9,10,11,12,13,15,17,18,19,20.1、17号产于紫红色晶屑熔结凝灰岩（K23C-2）中，U含量一般7〜11ppm,偏高场的展布方向成正北方向。由几个小晕圈组成，规模小， U含量低，连续性差，无构造痕迹，找矿意义不大。1,No.17inpurplecrystalignimbrite（K23c-2）,Ucontentisgenerally7~11ppm,intothenorthdirectionofhighfield.Composition,consistsofseveralsmallhaloofsmallscale,lowUcontent,poorcontinuity,nostructuraltraces,prospectingsignificance.

3号U偏高场位于5103矿床附近，分布于坑道口及堆矿场。U含量一般12.8ppm〜33.4ppm,最高含量为1109.8ppm。长600m，宽80〜230m，场值高，连续性较好。经实地调查由坑口、堆矿场矿渣以及流水冲积矿渣形成的大面积异常。无找矿意义。Uhighfieldislocatedinthe5103depositsnear,distributedintheaditandoreyard.Ucontentingeneral12.8ppm~33.4ppm,themaximumwas1109.8ppm.Long600m,width80~230m,thefieldvalueishigh,goodcontinuity.BasedontheinvestigationfromHangHau,mineslagheapandlargeareaofwaterslagformationofalluvialanomalies.Noprospectingsignificanee.6、8〜13、15、17〜20号晕圈场值低，连续性差，无构造痕迹，由花岗斑岩和晶屑熔接凝灰岩（K23C-2）局部增高引起，找矿意义不大。6,8-13,15,17~20,halofieldvalueislow,poorcontinuity,nostructuraltraces,bythegraniteporphyryandtuff(K23c-2)chipweldinglocalincreasing,prospectingsignificanee.从整体来看，铀的晕圈带的面积远大于总量的异常面积，其中 U-4、U-7和U-14这几个较高的铀偏高场并未在总量晕圈里，这几个异常带分别受几个主要控矿构造带控制，都具