Manual for Isoplot 37.docx

Manual for Isoplot 37.docx

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ManualforIsoplot37

User'sManualfor

AGeochronologicalToolkitforMicrosoftExcel

BerkeleyGeochronologyCenterSpecialPublicationNo.4

rev.August26,2008

KennethR.Ludwig

2455RidgeRoad,BerkeleyCA94709kludwig@bgc.org

TableofContents

INTRODUCTION5

ISOPLOT3REQUIREMENTS5

DEFAULTFOLDERSFOREXCELADD-INS6

PROBLEMSWITHEXCELVERSIONSFORTHEMACINTOSH6

INSTALLINGANDINVOKINGISOPLOT6

MemorySettingsforMacintoshComputersrunningOS-9orearlier7

Problems7

THEINPUTDATA-RANGE8

HEADERROWS8

DATAINASINGLE,CONTIGUOUSRANGE8

DATAINDISCONTINUOUSROWS9

DATAINDISCONTINUOUSCOLUMNS9

EXCLUDINGDATAWITHFONTSINSTRIKETHROUGH9

USINGBOLDEDFONTSTOSPECIFYADDEDEMPHASISTOPLOT-SYMBOLS9

SPECIFYINGSYMBOLCOLORSWITHFONTCOLORS9

EARLYVERSUSLATEDATASELECTION9

NUMERICOUTPUTFROMISOPLOT9

ISOPLOTCHARTS10

HIDDENWORKSHEETSCREATEDBYISOPLOT10

ADDINGNEWDATATOANEXISTINGCHART10

MODIFYINGCHARTS11

Selectingandmodifyingsimpledata-pointsymbolsandoutlineerror-symbols11

AddingData-PointLabels11

Embeddingchartsintothedata-worksheet11

Embeddingimagesofchartsintothedata-worksheet12

Superimposingcharts12

USINGFILLEDERROR-ELLIPSESANDERROR-BOXES12

COLOR-SCALINGOFFILLEDSYMBOLS14

EXPORTINGCHARTSTOOTHERPROGRAMS14

THEMAINISOPLOTDIALOGBOX15

ISOPLOTPREFERENCES19

NUMERICPREFERENCES19

GRAPHICSPREFERENCES20

CLASSICALERROR-WEIGHTEDX-YREGRESSIONSANDISOCHRONS22

REGRESSIONMODELS22

Model122

Model222

Model323

AWORDABOUT3-POINTISOCHRONS23

COMMENTSONREGRESSIONSWITHLOWPROBABILITIES-OF-FIT23

EXAMININGRESIDUALSOFREGRESSIONS24

ROBUSTREGRESSIONS25

U-PBCONCORDIAPLOTS26

CONVENTIONALVERSUSTERA-WASSERBURGCONCORDIAREPRESENTATIONS26

Asymmetric27

MonteCarlo28

SHOWINGDECAY-CONSTANTERRORSINTHECONCORDIACURVE29

SPECIFYINGTHESTYLEOFTHECONCORDIA-CURVEAGETICKS29

THE“CONCORDIA”AGE30

CalculatingaConcordiaAge30

CalculatingaConcordiaAge31

ConcordiaAgeMSWD’s31

ConcordiaAgeErrors31

EffectofDecay-ConstantErrorsonConcordiaAgesandErrors32

THREE-DIMENSIONALREGRESSIONSFORU-PBCONCORDIA32

PlanarRegressions32

Linear,Concordia-Constrained3-DRegressions（TheTotalPb/UIsochron）33

EXTRACTINGRELIABLEAGESFROMSUITESOFSINGLE-ZIRCON238U/206PBDATES35

PB-PBISOCHRONSANDGROWTHCURVES37

THE230TH-234U-238USYSTEM38

230TH/UISOCHRONSWITHVARIABLE234U/238U38

230TH/UISOCHRONSWITHSECULAREQUILIBRIUM234U/238U41

SINGLE-ANALYSIS230TH/UAGES41

WEIGHTEDAVERAGESOFASINGLEVARIABLE42

ARGON-ARGONAGESPECTRAANDPLATEAUAGES43

USER-SPECIFIEDPLATEAUSTEPS44

CONNECTINGLINESFORERRORBOXES44

THEARGON-ARGONPLATEAU-ISOCHRON44

CUMULATIVEPROBABILITYPLOTSANDHISTOGRAMS47

PROBABILITYPLOTS48

ADDINGANALGEBRAICALLY-DEFINEDCURVETOANEXISTINGPLOT.49

ADDINGANALGEBRAICALLY-DEFINEDCURVETOANEXISTINGPLOT.49

AGELIMITSFORASERIESOFDATED,STRATIGRAPHICALLY-ORDEREDUNITS50

STRATIGRAPHICALLY-CONSTRAINEDDATESWITHCLOSETOGAUSSIANUNCERTAINTIES50

STRATIGRAPHICALLY-CONSTRAINEDDATESFROM230TH/UANALYSES51

DECONVOLUTIONOFMULTIPLEAGECOMPONENTSUSINGTHESAMBRIDGE-COMPSTONALGORITHM52

YOUNGESTZIRCONINASUITEOFDETRITALZIRCONS53

UTILITYFUNCTIONSFORISOTOPICDATA54

ACCESSINGISOPLOT’SUSERFUNCTIONS54

URANIUM-LEADFUNCTIONS56

URANIUMSERIESFUNCTIONS59

OTHERRADIOGENIC-ISOTOPEFUNCTIONS60

STATISTICALFUNCTIONS60

ROUNDINGFUNCTIONS63

ACKNOWLEDGMENTS63

REFERENCES64

APPENDIXI:

TIPSONMINIMIZINGPLOT-CONSTRUCTIONTIME66

APPENDIXII:

TOOLBAR-ONLYFUNCTIONS67

APPENDIXIII–ERRORCORRELATIONS71

HOWTOCALCULATEANERRORCORRELATION71

Bydifferentiation71

Byobservation72

INDEX74

Introduction

Isoplot（an“Add-In”programthanrunsunderMicrosoftExcel）isaflexibletoolfortheinterpretationofradiogenic-isotopedata.Inadditiontotheplottingandcalculationoftheusual（Rb/Sr,Sm/Nd…）iso-chrons,Isoplotcan:

•ConstructU-Pbconcordiaplotsandcalculateagesusingconventionalconcordiaintercepts,the“ConcordiaAge”algorithm,3-Dplanarconcordiaintercepts,or3-Dlinear（“TotalU/Pb”）iso-chrons;

•Calculateuranium-seriesisochronagesusing3-Dor2-Disochronsandconstruct230Th/238U-234U/238Uevolutioncurvesandisochrons;

•Constructsingle-stagegrowth-curvesforplotsofcommon-Pbdata;

•Constructcumulative-probability+histogramplotsandlinearized-probabilitydiagrams;

•Calculateandconstructplotsforeithererror-weightedorrobust（nonparametric）averagesofasin-glevariable;

•Calculatebothconventional（analytical-errorweighted）androbust（nonparametric）x-yregressionsfor“classical”andPb-Pbisochrons;

•PlotAr-Arstep-heatingdiagramsandfindthestatistically-bestplateaustepsandage;

•CombineAr-ArisochronwithAr-Arstep-heatingdiagramstoobtainthelogicallyoptimumcombi-nationofboth;

•Plotcurvesforalmostanyfunction;

•UsesimpleBayesianconstraintsImprovetheestimatesanderror-assignmentsforapackageofstratigraphically-constrainedradiometrically-datedunitswhoseagesoverlapwithinerrors（withaspecialvariantfor230Th/Uages）;

•DeconvolutemixturesofcomponentshavingGaussianerror-distributionsusingtheSambridge-Compstonapproach;

•ProvideMonteCarloerrorsaswellasasymptotic（first-order）errorsformostlinearregressions,isochrons,andconcordia-interceptsolutions;

•ExtractreliableagesanderrorsfromcomplexsuitesofPhanerozoicsingle-zircondates;

•ExpandthenumberofExcelfunctionsbymorethan50,includingmanyfunctionsforradiogenic-isotopes（including16forU/Pband8for230Th-234U-238Ualone）.

Isoplotisavailablewithoutcharge–contactKenLudwigdirectly（kludwig@bgc.org）.

Isoplot3Requirements

ForWindowscomputers,IsoplotrequiresanEnglish-languageversion1ofExcel97,Excel2000,Excel2002orExcel2003.ForMacintoshoperatingsystems,youwillneedExcel98,Excel2001,ExcelX,orExcel2004.

Isoplot3isnotcompatiblewithExcel2007.IfyouabsolutelymustuseExcel2007,requestacopyIsoplot4,whichisrecommendedforExcel2007only.Isoplot4hasnomorefunctionalitythanIsoplot3.7,andsomewhatlessflexibility.Expectaspeedpenalyofaboutafactorof10whenusingExcel2007.

1ForWindowssystems,youmustsettheControlPanel'sRegionalandLanguageOptionstoEnglish）,andalsochecktheUseSystemSeparatorsboxintheInternationaltabofExcel'sOptionsorPreferencessheet.

DefaultfoldersforExcelAdd-Ins

ExcelforWindowsXPandMacOS-XseemtoberatherparticularaboutthefolderinwhichIsoplot.xlaresides.Recommendedfoldersare:

ExcelXP:

C:

\DocumentsandSettings\[UserName]\ApplicationData\Microsoft\AddIns

Excel2000:

C:

\ProgramFiles\Excel2000\Office\Library

Excel97:

C:

\ProgramFiles\MicrosoftOffice\Office\LibraryExcel98:

HardDisk:

MicrosoftOffice2001:

Office:

Add-insExcel2001:

HardDisk:

MicrosoftOffice98:

Office:

ExcelAdd-ins

ExcelX/2004:

HardDisk:

Applications:

MicrosoftOfficeX:

Office:

Add-ins

ProblemswithExcelversionsfortheMacintosh

•Thepositionofsuperscriptsinnon-horizontaltextiscorrupted,sothatverticalY-axislabelscannotbeconstructedwithsuperscripts.Youcan,however,stacksuperscriptedisotopes,suchas87Sr/86Sr,toavoidwastingplot-space（seetheOptions/Fontsdialogbox）.

•AfterseveralweeksofrunningIsoplotonsomeversionsofMac/Excel（OS-9orearlieronly,Ithink）,closingExcelorunloadingIsoplotcantakeaverylongtime—perhapsaminuteormore.Whenthisoccurs,findtheExcelToolbarsfile（generallylocatedintheSystem-Preferencesfolder）andtrashit.Ifallelsefails,tryre-installingExcelfromtheoriginalCD

•WithsomeG3MacsrunningSystem8,Excel（andthusIsoplot）mayslowdowntothepointofuse-lessnessifotherprogramsarerunning,regardlessofthememoryallocatedtoExcel.Ifyouexperiencesuchaproblem,youwillbeforcedtoclosesome（possiblyall）otherprogramstorunIsoplot.Oddly,whentheseproblemsexist,userswithEudoramusthaveEudoraopenatsomepoint（eitherbeforeEx-celisopenedorwhileitisopen）,andthencloseEudoratorestoreExcelperformance.

•SomeinstallationsofExcel-X（OS-X）donotsupportuser-definedtoolbarbuttons（noproblemwith

Excel98orExcel2001）–theiconsonalloftheIsoplottoolbar-buttonsturnintosmiley-faces.

•Excel'sCopy/Picturemethod,whichIsoplotusestoattachsmallchartstoworksheets,yieldsonlylow-resolutionimagesforallMacversionsofExcelexceptforExcelX.

InstallingandInvokingIsoplot

→IfyouhavebeenrunningVersion1ofIsoplot,youmustfirstfindtheoldIsoplot.xlafileandeitherde-leteitor（preferably）renameit（e.g.IsoplotOld.xla）.

StartExcel,andfromanopenWorksheet,selectTools/Add-Ins.IfIsoplot.xlaisnotinthelistofavailableAdd-Ins,selectBrowsetolocateit.IsoplotwillnowbeloadedeverytimeyoustartExcel（ifnotwanted,un-checkIsoplot/Ex3.00fromtheadd-inlistbeforeexitingExcel）.

WheninstallingExcel,youmustselectaprinter（saybyprintingany-

thingfromExcel）fromwithinExcelbeforetryingtorunIsoplot.

ToinvokeIsoplot,firstopentheWorksheetthatcontainsyourdata,andselect（withthemouseorkeyboard）thedata-rangethatyouwanttoworkwith（includinganyheader-row）.Then,either1）

presstheIsoplotbutton,onExcel’sStandardtoolbar（theoneatthetopofthescreen）,2）choose

RunIsoplotfromtheToolsmenu,or3）PressCtrl-I.

SomeinstallationsofExcel-X（Macintosh）donotsupportIsoplot’sToolbarbuttons

TheitemsintheIsoplotdrop-downmenucanalsob