GMAP2012 for Windows 7
Contents
1. If option b is selected the Q factor for every VGP in the table must be encoded in the first character of the VGP code see section 3 8 If a Q factor is not present included Q will be set to zero reliability If option c is selected the alfa95 must be included in the table of data 5 Input SMOOTHING PARAMETER value 10 to 10000 A high value results in extreme smoothing Values in the order of 100 to 200 generally result in moderate smoothing Fig 11 6 Input VGP FILE NAME for the output fitted path The fitted path when generated will be displayed on the graphic screen in option DRAW VGP 3 9 inthe main menu Note The original VGP file is shut down and replaced with the new APW file spline file 21 Page FIGURE 10 SPLINE FITTING option Left File data VGPs NorthAmerica2008_ROG vgp plotted with dp dm ovals Right Spline fitting with smoothing parameter 200 and weighted by alfa95 5 APW Path construction Moving average J ea 30 to 50 Lat 82 9 Long 343 5 495 3 3 N 11 40 to 60 Lat 81 3 Long 342 2 495 4 4 N 11 50 to 70 Lat 78 0 Long 351 6 495 4 5 N 9 60 to 80 Lat 76 5 Long 10 4 495 4 8 N 9 80 to 100 Lat 74 1 Long 18 3 A95 5 5 90 to 110 Lat 75 7 Long 0 6 A95 12 7 100 to 120 Lat 75 5 Long 3 9 A495 4 6 Plate f 01 70 to 90 Lat 75 1 Long 19 4 495 7 4 N 5 zzz 10 to 10 Lat 86 4 Long 208 4 495 19 8 N 3 Window Length Ma 20 D to2. When saving to Save to Vector WMF File RATE WFM file you can also open the vector drawing in a drawing package later Clipboard Setting Vlipboard setting should normally be set to Metafile 2 Exchange setting through ClipBoard isi Clipboard Data Format Options W Metafile Exit M Enhanced Metafile DIB Palette IV Clear before copy Only Selected 4 0 Continent VGP Animation 4 1 OPEN CONTINENT VGP or ANIMATION files A list of CONTINENT file extension C97 VGP file extension VGP or ANIMATION file extension A97 are displayed Select the appropriate directory drive and file name followed by lt OK gt A range of CONTINENT VGP ANIMATION files can be found in c gmap data continents c gmap data VGPs and c gmap data ANIMATIONS The CONTINENTS are also found in the ANIMATION directory but all files in this directory are Read Only to avoid overwriting original system files CONTINENTS starting with a 3 digit number mainly follows GPlates Plates conventions 4 2 MERGE CONTINENT VGP or ANIMATION This option is identical to that described above but the selected file will be merged with an existing CONTINENT VGP ANIMATION file in memory These combined data can later be saved to a disk file using option SAVE AS CONTINENT VGP or ANIMATION Note however that the maximum 10 Page permitted number of co ordinates in a single continent outline is 30000 and 2000 data points in a VGP file 4
3. reconstructed position North American craton will be displayed on the screen in a Devonian 400 Ma configuration in European co ordinates A North America Today B Rotated to Europe C Reconstructed with 400 Ma from Baltica Europe Baltica Europe APWP shown from 530 tp 250 Ma and plotted with A95 FIGURE 3 Example of compound rotation A North American craton displayed in present position B Rotated into a Bullard et al fit lat 87 long 27 angle 37 with Europe taking account of the 12 Page opening of the North Atlantic C The corrected NAM positioned according to pole 41 in VGP file data VGPs Baltica_ Europe 2012 4 5 VGP RECONSTRUCT This option performs a reconstruction based on a VGP inputted from the keyboard Enter VGP latitude and longitude and state whether it is a SOUTH s or NORTH n pole Example of how to produce a display for a map ofthe Permian palaeo position for Baltica 1 Load BALTICA file data continents 302_ Baltica 1100 C97 using OPEN CONTINENT 2 Select option VGP RECONSTRUCT and enter 45 VGP latitude and 340 VGP Longitude 3 Select southpole and click on lt OK gt SS VGP Reconstruction bo an Continent 302 Baltica 1100 ee YGP Latitude South Pole 45 C North Pole YGP Longitude 340 Ok Cance 4 BALTICA will be displayed in DRAW CONTINENT in its PERMIAN position N60 N30 4 6 DRAW CONTINENT or VGP amp ANIMATION
4. 3 SAVE AS CONTINENT VGP or ANIMATION The purpose of this routine is to save modified CONTINENT VGP or ANIMATION data to disk files Merged CONTINENT files EDITED CONTINENTS or rotated CONTINENT data can be saved under a new file name The latter is useful for constructing ancient terranes or storing palaeogeographic maps In option DRAW CONTINENT one can also add points lines to the existing CONTINENT file which can later be saved under this option 4 4 ROTATE CONTINENT or VGP Define euler data before selecting this option either manually using the KEYBOARD INPUT option in the Euler menu or from a file using the OPEN option When rotating VGP s one can also rotate the sampling site latitude and longitude to permit the generation of proper error ovals on data in their rotated positions Note that the CONTINENT outline VGP s in memory are changed during rotation To later perform a rotation on the original data set the original continent file must first be re loaded Compound rotations can be performed using KEYBOARD INPUT and ROTATE CONTINENT VGP repeatedly Example of compound rotation Problem You wish to rotate the North American craton to its Devonian palaeoposition according to palaeomagnetic data from BALTICA 1 Select option OPEN CONTINENT 2 Open North America craton file data continents 101_North American craton 1100 C97 If you now use option DRAW CONTINENT a map like Fig 3A will appear on
5. 40 4 66 55 33 355 22 78 00 346 20 8 00 101 00 50 00 7 ARM 50 x oo 7 3 04 56 12 354 64 77 17 346 13 13 00 101 00 60 00 8 ARM 60 3 11 55 40 355 84 75 66 345 52 7 00 101 00 70 00 g ARM 70 3 87 46 78 i r 72 32 333 17 4 00 101 00 80 00 10 4RM 80 100Ma N 4 Dp 196 a 56 e E 48 T 73 E EN m 101 T 90 00 11 4RM 90 110Ma N 2 Dp 19759 69 25 1427 5659 58 50 78 61 35204 200107 00 100 00 aan An This is the most heavily used routine in performing reconstruction s based on palaeomagnetic data This function is also available in the main menu under the name VGP RECONSTRUCT In GMAP the euler pole and rotation angle which is required to rotate the selected VGP to the present geographic NORTH n or SOUTH s POLE is determined and becomes the current setting for the euler rotation listed under the main menu The user must note that any pole position can result in two possible palaeo positions for a continent one opposite to the other depending on the poles polarity Therefore attention should be paid at all times to the polarity of the VGP s in the table so that proper account can be taken of it Note that the function below APW PATH requires that all the VGP s in the table have the same polarity In order to use this option first load a VGP file and the contenent you wish to reconstruct Click in the table on the line pole you wish to use for reconsruction 6 4 APW PATH To aid the definition of APW tre
6. co 186 31 57 66 Br 45 05 4 27 81 77 327 21 7 00 101 00 10 00 31 4RM 10 30Ma N 4 Dp ci 187 27 53 64 7 60 44 30 3 47 78 61 331 57 4 00 101 00 20 00 4 4RM 20 40Ma N 2 Dp c 187 49 61 24 21 06 50 55 7 50 80 30 332 60 2 00 101 00 30 00 5 ARM WARNING ONLY pole 161 06 60 19 3 40 50 30 2 00 80 78 2 00 1 00 101 00 40 00 6 ARM 40 60Ma N 8 Dp c 162 5 62 17 4 66 55 43 355 22 786 00 346 20 8 00 101 00 50 00 2 4RM 50 70Ma N 13 Dpi 162 59 62 13 3 04 56 12 354 64 77 17 346 13 13 00 101 00 60 00 8 4RM 60 80Ma N 7 Dp ci 183 38 60 30 3 11 55 40 355 64 75 66 345 52 7 00 101 00 70 00 9 4RM 70 90Ma N 4 Dp c 197 59 54 48 3 87 46 78 27 74 72 32 333 17 4 00 101 00 60 00 10 4RM 80 100Ma N 4 Dp 196 18 56 47 6 22 46 76 29 23 73 39 338 13 4 00 101 00 90 00 11 4RM 90 110Ma N 2 Dp 197 59 69 26 14 2 56 59 59 50 78 61 352 04 2 00 101 00 100 00 12 ARM WARNING ONLY pole 191 74 66 53 2 50 44 50 102 00 80 78 338 40 1 00 101 00 110 00 13 4RM INTERPOLATED 187 49 61 24 0 00 50 55 7 50 78 77 349 77 2 00 101 00 120 00 Column o 2 CLPOL Combined character string of Van der Voo classification grading 1 7 and palaeomagnetic polarity n r m This string is important and controls weighting in the fitting of smooth APW paths For example a pole with Q factor 7 and normal polarity are entered as 7n 3 DEC Remanence Declination 4 INC Remanence Inclination 9 PLON 12 AGE VGP age All poles must be assigned an a
7. 20 Lat 85 1 Long 216 1 A95 12 4 N 4 10 to 30 Lat 84 2 Long 328 4 495 5 3 N 8 Incerement Mal fi 0 20 to 40 Lat 83 0 Long 343 9 495 3 6 N 10 laj 1 Exit FIGURE 10 MOVING AVERAGE option on file data VGPs NorthAmerica2008_ROG vgp and plotted with A95 ovals 22 Page 7 TABLE ANIMATION a Table Animation File Edit Add Euler poles Vgp Rotate Continent E Lat E Lona E Angle Age Comment 1 c4gmap Datat nimations 101 North Ar 60 45 69 53 72 48 250 2 c 4gmapiDatat nimations4102 Greenla 51 36 78 37 64 67 250 3 c 4gmap Datat rnimations4103 North SI 33 13 84 23 58 23 250 4 c4gmap Datat nimations4104 Caborcz 53 02 80 37 72 3 250 5 c4gmapiDatat nimations4108 Acadia 60 45 69 53 72 48 250 6 c gmap Datat nimationst108 Acadia 60 45 69 53 72 48 250 7 c4gmapiDatat nimations4108 Acadia 60 45 69 53 72 48 250 8 c 4gmap Datat rnimations4109 Florida L 60 45 69 53 72 48 250 9 c 4gmapiDatat nimations4109 Florida 60 45 69 53 72 48 250 10 c 4gmap Datat nimations 109 Florida C 60 45 69 53 72 48 250 11 c 4gmap Datat nimations4109 Florida 60 45 69 53 72 48 250 12 c 4gmap Datat nimations4109 Florida C 60 45 69 53 72 48 250 13 c 4gamap Datatdnimations4111 Mendelt 57 64 73 4 78 75 250 14 c 4gmap Datatdnimations4113 Northwi 57 64 73 4 78 75 250 15 c gmap Data 4nimations 114_Lomono 54 26 74 03 64 39 250 16 c 4gmap Datatdnimations41 20 Sverdru 60 45 69 53 72 48 250 17 c4gmap Datat nimations 1
8. 21 Southwi 52 13 78 89 65 1 250 18 c 4gmap Datatdnimations4122 South c 51 9 80 45 63 8 250 19 c 4gmap Datat nimations 1 23 Central 59 81 69 84 73 12 250 20 c 4gmap Datat nimations 124 North El 60 45 69 53 72 48 250 21 c 4gmap Datat nimations41 30 Artic Ca 52 13 78 89 65 1 250 22 c gmap D ata 4nimations 140_Lomono 54 2 73 99 64 3 250 23 c4gmap Datat nimations4141 Lomono 53 85 73 69 63 76 250 24 c 4gmap Datat nimations4142 Lomono 31 07 85 5 42 55 250 25 c 4gmap Datat nimations4153 Roberts 60 27 69 55 71 76 250 26 c 4gmap Datatdnimations 154 Laurenti 60 27 69 55 71 76 250 27 c qmap Data4nimations 155 Farewel 63 47 84 57 69 64 250 28 c 4gmap Datatdnimations4160 Ruby Te 33 13 84 23 58 23 250 29 c 4gmap Datat nimations4161 E astem 60 27 69 55 71 76 250 30 c 4gmap Datat nimations4201 Northerr 68 74 91 97 44 2 250 All m4nmanNatat nimatinns4 N Parana z709 AR 24 43 13 AN Double click a line to insert a continent with file manager This option is used to edit use option OPEN ANIMATION or create animation files The main menu consists of the following options File New Create a new file Export To EXCEL To GMT all reconstructed To GPlates rotation format Copy Euler Poles to VGP Copy Euler poles to memory and display with DRAW VGP Exit 1 it uler poles otat File Edit Add Eul pol Vgp R New Export Copy Euler Poles to VGPs Exit Edit Edit a row Edit a single line Select line by clicking o
9. GMAP2012 for Windows 7 USER MANUAL AND EXERCISES GMAP Window 7 Edition Trond H Torsvik 1982 2012 ERPS S oo OOOO 949 istaimede eee Ta PANTHALASSA A NT 2 E Antarctica PHYSICS OF tg PG GEOLOGICAL Excellence Sey PROCESSES Trond Helge Torsvik PGP University of Oslo Norway 1 Page Software Installation This preliminary manual can be found at http www earthdynamics org Bugs Gmap2012Manual pdf A INSTALL SYSTEM CLICK ON LINK BELOW http www earthdynamics org Bugs Gmap2012System zip File Download jm 23 Do you want to open or save this file F Name Gmap2012System zip Type Compressed zipped Folder 18 4MB From www earthdynamics org Always ask before opening this type of file Py While files from the Intemet can be useful some files can potentially ME ham your computer If you do not trust the source do not open or save this file What s the risk 1 Click Save in File Download Box see above 2 After the File has been downloaded then click on file to unzip and click setup exe see below Name Type Compressed size GMAP2012 CAB Cabinet File 18 804 KB m i setup exe Application 66 KB SETUP LST MASM Listing 2 KB 3 During setup the software must be installed to c gmap VERY IMPORTANT Note also that you must have administrator rights to install the system During intallation you should keep system files that are more recent then th
10. In this option a CONTINENT VGP or ANIMATION file is displayed on the screen using the pre defined projection Use option PROJECTION to alter projection type see picture below The plot is centred on a zoom centre which by default is 0 0 LAT LONG Blanking is ON by default 13 Page E Projection Types la eee Sanson F Schmidt Mollweide Orthogonal Kavraiski These projection types have special built routines for zooming translantion etc Projection Center Lat Long Spacing 4 4 _ Latitude 0 Ca Cig KI 1 o gt Longitude 0 C5 30 al gt Picho C10 CA Cancel ENQ 5 0 Euler Rotations Keyboard Input Euler rotation Calculate E P Add Euler Poles Euler Fit 4 point 5 1 KEYBOARD INPUT EULER This option enables the input of an Euler rotation pole from the keyboard which can subsequently be used by options ROTATE CONTINENT or VGP or EULER ROTATION 5 2 EULER ROTATION This utility routine performs euler rotations on VGP s entered interactively from the keyboard The currently registered Euler Pole 3 13 or 3 14 is used amp Euler Rotation am Lola ln Rotated Latitude Rotated Longitude 5 3 CALC EULER POLE This option enables calculation of an Euler rotation pole based on manual input of two geographic point co ordinates or poles Enter Latitude LAT and Longitude LONG for pole A and B and the resultant rotation pole LAT amp LONG an
11. OTE THAT ANIMATION FILE CAN BE INSPECTED AND MANIPULATED IN ANIMATION TABLE AND THEN CLICK ANIMATION DRAW THE USER CAN ALSO ADVANCE OR DECREASE AGE IN 5 MA INTERVALS BY CLICKING THE ARROWS BELOW OR PLAY A MOVIE ANIMATION FILTER E G 7 WILL SHOW ALL CONTINENTS STARING WITH 7 E G SOUTH AFRICA IS 701 OR TYPE 302 TO JUST DISPLAY BALTICA 9 Page 3 0 ORGANIZE Import gt Aschi Import Continent Export Continent Ascii GMT Excel GIS GEN ShapeFile Import continent Export Continent to Shape Files 4 Print Print Setup Problem Reading VGP files Exit 3 1 IMPORT 3 1 1 ASCII IMPORT fe Aschi File Import X This option allows import of Ascii continental files which are stored as longitude latitude A list of CONTINENT file extension file names are displayed in alphabetic order Select the appropriate directory drive and file name followed by lt OK gt Pen up command in GMAP continent files are 100 latitude and 1000 longitude This is a simple Aschi file import routine Files should have no name extension and the file must consist of only two columns latitude longitude or longitude latitude Select data column format below Data Format Latitude Longitude Longitude Latitude 3 2 SCREEN Continent VGP Animation When clicking Copy to Clipboard you can later Paste the screen into a Coprite Cipinani drawing package in vector format e g Adobe Illustrator
12. d amount of rotation A ROT will be displayed 14 Page amp Calculate Euler Rotation Pole Latitude POLE A 33 Latitude POLE B 12 Latitude EULER POLE Longitude Longitude Longitude Angle 5 4 ADD EULER POLES This option add concatenates two Euler poles into a single resultant Euler pole Enter latitude longitude and angle for the two Euler poles and click on lt Calculate gt Add Euler Poles rii A Latitude Longitude Angle POLE A 34 55 18 POLE B 2 Ro R COMBINED 33 19612 35 07643 29 21585 Right hand rules angles must be less than 180 degrees 5 5 EULER FIT 4 point 2 4 Point Euler Fit Latitude Longitude Point 1 Point 2 Point 3 Point 4 OL ON O JU E JI a Most significant II Ls j First Euler Fit Excact 1 to 2 Latitude Longitude Angle ES 3 Rotated Iteration for best fit 3 to 4 Latitude Longitude DD Best Fit Euler Rotation Exit Calculate Rotation Misfit Deg 15 Page 6 TABLE VGP This is one of the most frequently used options in GMAP Upon selecting this option the following table is displayed J labie ver rorbarcaturope 44 lll Organize Reconstruct APWPath Calculate Edit Plot Tools mA CLPOL CODE DEC INC a95 GLAT GLON PLAT PLON Dp F Dm AGE 1 4RM 10 10Ma N 5 Dp c 167 90 60 10 5 51 45 63 4 90 82 51 312 16 5 00 101 00 0 00 2 4RM 0 20Ma N Dp
13. e one supplied with GMAP you will be asked If any problem installing some files just click skip B INSTALL DATA CLICK ON LINK BELOW http www earthdynamics org Bugs Data zip 1 Click Save in File Download Box see below ET ll Do you want to open or save this file Name Data zip Type Compressed zipped Folder 25 7MB From www earthdynamics org V Always ask before opening this type of file harm your computer If you do not trust the source do not open or A While files from the Intemet can be useful some files can potentially o save this fle What s the risk 2 After the File has been downloaded click data zip and copy the entire directory dat with its subdirectories to c gmap The structure must be c gmap data subdirectories Name Type Data File folder Name i Type d Animations File folder i Animations Copy File folder P Continents File folder GPlates File folder M Gpmdb File folder JM IGCP440_Blocks File folder gt Old Continents File folder ad Output File folder ad System File folder od VGPs File folder di Your_Animations File folder _ Combined c97 C97 File _ Gondwana_SAF a97 A97 File _ Gondwana SAF c97 C97 File Laurentia_NAM a97 A97 File 9 RotExport rot ROT File test a97 A97 File 3 Page 1 INTRODUCTION GMAP for Windows 7 is a state of the art computer program which performs all processing and plotting tasks usually associa
14. e the palaeomagnetic pole position for all data in the Table Declination inclination and sampling position present in data set Pole Reference Calculate amount of rotation and flattening Enter Reference Pole and A95 Calculate Dec Inc Calculate declination and inclination Based on VGP latitude amp longitude and sampling position Plat Reference Enter latitude amp longitude optional for which palaeolatitudes are to be determined Note that latitude amp longitude will replace original sampling co ordinates in the Table This enables the operator to calculate local declination and inclinations at the selected reference locality Single VGP Calculation Calculate a pole based on dec inc and sampling location Non dipole field correction Type G1 and G2 and inclination and pole will be recalculated 17 Page Inclination Error Correction Calculate Edit Plot Tools Pole Statistics Calculate Poles Pole Reference Calculate Dec Inc Plat Reference Single VGP calculation Non dipole field correction same value Inclination Error correction same value Inclination Error Correction from f value in dp COLUMN Edit Delete row s Add a row Invert row s Invert all rows Sort a column Plot Tools Delete row s Add a row Invert row s Invert ALL rows Sort a column Plot Palaeolatitude Stereoplot Histograms APW Tools Palaeolatitude Stereoplot Wulf Histograms APW Tools Calculate Euler poles f
15. ed to a continent held fix see Add Euler Poles above then you can use a VGP from that ae eee continent to all rows in the animation file and YGP Latitude South Pale o thus make your own absolute reconstruction YGP Longitude 0 Ok Cancel E VGP Reconstruction l l E s The input format in ANIMATION files is as follows 1 CON Name of continent CON file 2 LAT Latitude of Euler Pole 3 LONG Longitude of Euler Pole 4 ANGLE Rotation angle about Euler Pole clockwise counterclockwise 5 COMMENT Comment any text 24 Page 8 VELOCITY The main purpose ofthis option is to calculate latitudinal drift rates and rotational velocities for continents or terranes This option old and not updated yet is found in VGP Table and Tools and options are as follows OPTION SUBOPTIONS EFFECT exit Return to VGP Table menu VGP Open VGP file Merge VGP file Open a VGP file from disk Open a VGP file from disk displayed together with existing VGP data in subsequent graphic actions Calculate and displays palaeolatitude drift rates and angular rotation Calculate and displays APW Copy graphics to HPGL plotter or file Analysis 1 Velocity and Angular Rates Analysis 2 APW rates HPGL write to file Print Settings TimeScale Polarity Bias Open VGP file Merge VGP file Analysis 1 Velocity and Angular Rates Analysis 2 APW Rates HPGL write to file Settings Set
16. ge if a smooth path is to be fitted to them During hard copying of VGP data the age will be printed next to the pole Note that VGP files created with GLOBAL EXE The Global Palaeomagnetic Database Query program substitute column 2 CLPOL with RESULT NUMBER in the Global Palaeomagnetic database Column 12 AGE is a mean of Low and high magnetic age stated in the database 16 Page 6 1 MAIN MENU AND SUBOPTIONS OPTION SUBOPTION EFFECT Organize Open Open a VGPfile Save Save VGP File Save As Save VGP with a new name GlobalPalmagDatabase Search global palaeomagnetic database New Create a new VGP file Use option EDIT to input data Print Print table to default printer Exit Return to main menu Organize Reconstruct APW Path Open Save Save As Global PalmagDBase New Print Export to GMT ASCI file Export to EXCEL Import IAPD Exit Perform a reconstruction based on a VGP in the table Note Load a continent prior to this operation Select reconstruction pole by clicking on numerical row code at the first column Select North or South pole Resulting reconstruction will be displayed in mode DRAW CONTINENT APW Path Spline Fitting Fit a smooth APW path to the data in the Table using splines Moving Average Fit a smooth APW path to the data in the Table using running means Voo Grading Q Timescale not updated Calculate Pole Statistics Calculate mean of the listed VGP s A95 Calculate poles Determin
17. ion is useful when dealing with displaced and rotated terranes A Pole Latitude for South reference pole in the term of latitude longitude and A95 is required Pole Longitude Based on this reference pole the declination differences between the reference and tabulated data are calculated This provides estimates of the potential A95 z E rotation angle about a vertical axis of each pole in the table relative to the reference pole Differences in inclination are also calculated which provide estimates of palaeolatitudinal differences or remanence flattening When using the PRINT TABLE option above after performing this calculation a detailed listing of estimated rotation and flattening angles together with the associated errors will be printed On the screen the data will be displayed from column 12 and onwards 6 3 RECONSTRUCT Organize Reconstruct APW Path Calculate Edit Plot Tools ARM 90 110Ma N amp VGP Reconstruction 15 CLPOL d Continent 302 Baltica 1100 GLAT GLON PLAT PLON Dp F Dm AGE 1 4RM 10 5 51 45 83 4 90 82 51 312 16 5 00 101 00 000 ol 4RM 0 AN es VGP Latitude 5 17 45 05 4 27 81 77 327 21 7 00 101 00 10 00 3 aRM 108 i 78 61 7 60 44 30 3 47 78 61 331 57 4 00 101 00 20 00 a aRM 204 A North Pole VGP Longitude 21 06 50 55 7 50 80 30 332 60 2 00 101 00 30 00 5 ARM WA 04 3 40 50 30 7 00 80 78 2 00 1 00 101 00 40 00 6 ARM
18. n numerical row code at the first column Add a row Add a row to the Table Delete a row Delete one or several lines Select line s by clicking on numerical row code at the first column or drag the mouse to include several lines Sort Ages 23 Page Subsitute All Continents with same continent Edit Add Euler poles Vgp Rotate Edit a row Add a row Delete a row Change Euler Pole Polarity Sort Ages Substitute All Continents with same Continent Add Euler Poles Add Euler Rotation of Selected Row to All Example All supplied animations are Rows negative angle palaeomagnetic reconstructions in a South Africa frame plate 701 If you want to display the data relative a fix North america then click the row 101North America And engage this option If you have a new pole from North America at this time engage VGP rotate to make animation file absolute based on your new pole Add Euler Rotation to all Rows Add the same Euler to all rows Add Euler Rotation to Selected Rows Move Continents East or Westward As above but rotating about 90 or 90 so only change longitude if animation file is based on palaeomagnetic data calibrating longitude Add Euler poles Vgp Rotate Add Euler Rotation of Selected Row to All Rows negative angle Add Euler Rotation to all Rows Add Euler Rotation to selected Row s Move Continents East or Westward VGP Rotate Supplied animation file are absolute but if first rotat
19. nds within tectonic units and to compare such trends between tectonic units GMAPW includes a method of fitting smooth path to a series of VGP s of various ages 19 Page which has a location and time progression Path fitting constitutes interpolation reducing data sets to a simpler and to some extent interpreted form A number of numerical methods for fitting smooth paths to palaeomagnetic poles have been offered in the literature Gould 1969 Parker and Denham 1979 Thompson and Clark 1981 1982 Clark and Thompson 1984 Jupp and Kent 1987 In GMAP we have used the method of Jupp and Kent 1987 because it is statistically rigorous is independent of the co ordinate system and is most sympathetic to the concept of APW The method aims to fit spherical smoothed splines to a given data set consisting of pole positions and error parameter It is possible to generate a number of paths with different levels of smoothing This is done by adjusting a smoothing parameter used by the computer program In GMAP the data can be individually weighted according to their alfa95 so that the route taken by the smooth path through the data set will depend on both the distribution of the data on the globe and the standard error for each of the palaeopole positions The lower the reported angular error for a pole position the closer the curve will pass by it We have also implemented a weighting procedure based on the Van der Voo s 1988 reliabili
20. ng of NET set to OFF to ON OFF WMA gt Select scale magnification centred a 5 M Mi around zoom centre Click with mouse ay p EE Set reconstruction in Myr Built in at the appropriate scale value 7 S ANIMATION files in5 Myr interval 250 Apply A e 9 0 5 10 etc back to 550 Ma Click arrows to move back gt or forward lt in time Double arrows starts a continous movie Use to only show continents starting with e g 7 Africa or e g just Baltica type 302 nm Animation Filter tie gan Set Color for CONTINENT VGP fill M vopovairin e and CONTINENT color Change Continent Color KIIS between filling or no filling mode PANEL OPTION EFFECT SET PROJECTION TYPE SEPARATE FORM WILL APPEAR Projection center SET LATITUDE AND LONGITUDE FOR PROJECTION CENTER ALSO AVAILABLE IN PROJECTION SUB OPTION MUST ENGAGE DRAW CONTINENT VGP OR ANIMATION TO TAKE EFFECT CHANGE BETWEEN BLANK ON AND BLANK OFF BLANK ON IS DEFAULT AND TO PRESERVE A PICTURE DURING SUCCESSIVE LOADING OF CONTINENTS OPEN CONTINENT THIS OPTION MUST BE SET TO OFF CLICK WITH MOUSE FOR THE APPROPRIATE STATE Grid SET AUTOMATIC DRAWING OF NET TO ON OFF CLICK WITH MOUSE FOR THE APPROPRIATE STATE Scale SELECT SCALE MAGNIFICATION CENTRED AROUND ZOOM CENTRE CLICK WITH MOUSE AT THE APPROPRIATE SCALE VALUE 50 2000 Animation Library Apply TYPE A NUMBER IN MILLION OF YEARS NEAREST 5 MILL YEAR 0 5 10 ETC MAXIMUM AGE IS 550 MA N
21. on file VELW SET VELWIN configuration file C97 Continent outlines CON in very old releases VGP Files containing virtual geomagnetic poles VGP A97 Animation files ANI in very old releases 1 2 ABBREVIATIONS VGP VIRTUAL GEOMAGNETIC POLE APW APPARENT POLAR WANDER APWP APW PATH CONTINENT A FILE CONTAINING LATITUDES AND LONGITUDES THESE CAN W G BE COASTLINES OR TERRAIN BOUNDARIES Qos 95 PERCENT CONFIDENCE CIRCLE ON MEAN REMANENCE A95 95 PERCENT CONFIDENCE CIRCLE ON MEAN POLES 4 Page dp dm DEC INC GLAT GLON PLAT PLON FISHER 1953 PRECISION PARAMETER SEMI AXES OF THE OVAL OF 95 PERCENT CONFIDENCE ABOUT THE VGP MEAN REMANEKCE DECLINATION MEAN REMANENCE INCLINATION LATITUDE OF SAMPLING SITE LONGITUDE OF SAMPLING SITE VGP LATITUDE VGP LONGITUDE 5 Page 2 DESCRIPTION OF GMAP for Windows 7 Select GMAP from the Program Manager Window option and double click the GMAP for Windows icon After start up the main menu is displayed Fig 1 An option in the top menu orthe left hand and rigth hand panels Fig 2 may be selected through the use of the mouse and executed by clicking the mouse FIGURE 1 Main menu GMAP GMAP Windows 7 Ed Organize Screen Continent VGP Animation Euler Rotations LAPD2012 Euler Info 2 1 MAIN MENU OPTION SUBOPTIONS Organize Organize Screen Continent VGP Animation Euler Rotations IAPD2012 Import b Export Continent Ascii GMT Excel GIS GEN Exp
22. or VGPs Check poles Interpolate VGPs Non dipole Field vs Latitude Inclination Error vs Latitude Velocity Tools Calculate Euler poles for VGPs Check Poles Interpolate VGP s Non dipole Field vs Latitude graph Inclination Error vs Latitude graph Velocity Type f flattening factor and inc and pole will be recalculated Delete one or several entries in the Table Select pole by clicking on numerical row code at the first column or drag the mouse to include several poles Add a pole to the Table Invert VGP polarity of one or several poles Invert VGP polarity of all poles Sort data based on any column Select column by clicking at the first row Calculate and display latitudes based on inclination Display dec and inc in a Wulf plot Display data in histogram select column to display Calculate APW and display in X Y plot Calculate Euler poles for entire Table Select North or South pole Cross checking type pole and calculated from dec inc and location Interpolating by typing interval Draw a graph based on G1 and G2 Draw a graph based on f flattening factor Engage calculation of velocties from VGPs very old routine Note All alterations to data in the Table will only affect the dataset in memory and not on the disk To save alterations made in TABLE VGP to disk use option SAVE AS VGP in the main menu 18 Page 6 2 POLE REFERENCE amp Pole Reference gt This opt
23. or spline see SETTINGS cf 3 20 2 and parameter Plot declination should be set to on This will produce a display as illustrated in Fig 16 VGP file B20092 used for Baltica by Torsvik et al 1992 where declinations according to a reference locality 6 00N and 100E in our example are plotted along the latitudinal drift curve i e a natural cubic spline curve Based on the setting of the Time Window parameter cf 3 20 2 this option calculates latitudinal drift rates in cm y and rotational velocities in o Ma Drift rates are automatically seperated into Northward UPPER part of diagram or Southward LOWER part of diagram movements middle diagram in Fig 16 whereas rotational velocities are separated as clockwise UPPER part of diagram or counter clockwise LOWER part of diagram rotations Analysis of original data If the VGP file contains original data the parameters Original data and Plot latitude error cf SETTINGS 3 20 2 should be set to on This produces a display as illustrated in Fig 17 VGP file Bal92 used for Baltica by Torsvik et al 1992 where palaeo latitudes according to the reference locality are plotted with error bars based on alfa95 FIG 16 Example of option VELOCITY VGP file B20092 using an APW spline path FIG 17 Example of option VELOCITY VGP file BAL92 using original data 3 20 2 SETTINGS This option permits the adjustment of parameters which con
24. ort Continent to Shape Files Print Print Setup Problem Reading VGP files Exit OPTION SUBOPTION ShapeFile Import Export Continents Ascii GMT Excel GIS GEN KAA 6 Page Export Continents to Shape Files Print setup Continent Continent VGP Animation Euler Rotations lAPD2012 Open Save As Merge Library Draw Rotate VGP Animation Euler Rotations IAPD2012 Open Merge Library Draw Table Rotate Vgp Reconstruct Plot Settings Goray 7 Page Animation Euler Rotations IAPD2012 Open Save As Merge Draw Table Library OPTION EFFECT LOAD AN ANIMATION FILE SAVE AN ANIMATION FILE TO DISK wer Euler JAPD2012 Keyboard Input Euler rotation Calculate E P Add Euler Poles Euler Fit 4 point Keyboard input DEFINE A EULER POLE AND ROTATION ANGLE Euler rotation PERFORM AN EULER ROTATION Calculate E P CALCULATE AN EULER POLE Add Euler poles CALCULATE AN EULER POLE BASED ON TWO SEPARATE EULER POLES 8 Page 2 2 LEFT HAND PANEL Euler data will be listed here e g though Euler Info KEYBOARD INPUT or VGP RECONSTRUCT op Tl Latitude Longitude Angle Click to Set projection type am G Projection Change Projecten Center Change between BLANK ON default and e BLANK OFF To preserve a picture during LAIULE rosar JF successive loading of e g continents tam fo lo OPEN CONTINENT this option must be 7 Blank IY Grid Ses as Set automatic drawi
25. system parameters that control the program performance automatically stored during Exit lole e Reference Latitude for South Reference Longitude for West 60 308 Ey Settings for File Start Time in Ma End Time in Ma Time Window in Ma 50 230 10 Invert latitudes Yes Plot declination APW path or spline C No Plor latitude error Original data Expanded Latitude plot Amplitude Latitude Plot in Deg 90 Amplitude drift velocity in cm vr 12 Amplitude rotation plot in DEG Ma Yes No 0 Amplitude CUM APW in Deg 700 Timescale Printer Setup Amplitude APW rate in cm yr 30 Ok Use Gradstein et al 2004 Build your own Polarity Bias Use Gradstein et al 2004 Build your own Polarity Bias Open Polarity File About Polarity Table Analysis 1 Age Sliding Analysis 2 Chron Sliding HPGL write to file Gradstein et al 2004 Modify timescale auto saved to a system file 25 Page 3 20 1 DRIFT ANGULAR RATES Based on a seguence of ordered sorted with increasing magnetic ages VGP poles either original data or APW spline data this option provides an analysis and display of palaeo latitudes for a given reference locality see 3 20 2 through geological time top diagram in Fig 16 Analysis of APW paths If the VGP file contains an APW or spline path cf 3 11 3 parameter APW path
26. ted with the storage and presentation of palaeomagnetic pole positions and generation of palaeogeographic reconstructions GMAP is menu driven and easy to use the user is never far removed from the basic data from which palaeogeographic reconstructions are derived and therefore has a sense of total control over the program s performance GMAP can generate reconstructions based on individual palaeomagnetic poles averaged palaeomagnetic poles and digitally derived smooth APW curves Palaeogeographic reconstructions can be saved to disk files and later viewed in chronological order as animations GMAP is supplied with a full range of continental outlines It is also possible to import new continents via simple ASCII files or ARC GIS shape files The GMAP software system package was originally developed by Torsvik at the University of Bergen in 1982 and later with contributions from both Lauri Pesonen and M A Smethurst Torsvik amp Smethurst 1989 GMAP routines are currently beeing ported to GPlates www gplates org and this GMAP version is similar to earlier versions but can run under Windows 7 older 16 32 bit Editions versions not compatible with Windows 7 1 1 MAIN PROGRAMS AND FILE TYPES Main program GMAP2012 EXE Palaeogeographic reconstruction program Programs run from inside GMAP APW EXE APW Path fitting routines VELWIN EXE Calculates drift and rotation rates from APWP s Data file types GMAPW SET GMAPW configurati
27. the screen 3 Use option KEYBOARD INPUT in the Euler Rotations menu to register the rotation pole and angle which corrects for the Mesozoic Cenozoic opening of the North Atlantic e g use a classic Bullard et al 1965 fit c 87 latitude 27 longitude and 37 euler angle 4 Select option ROTATE CONTINENT The continent outline will then be adjusted for the opening of the North Atlantic If you then use option DRAW CONTINENT a map like Fig 3B appears on the screen 5 Select option OPEN VGP 6 Open the fitted APW path for BALTICA Europe e g file data VGPs Baltica_ Europe 2012 vgp supplied with the GMAP package 11 Page 7 Select option TABLE VGP in the VGP menu 8 Select reference pole e g pole 41 corresponding to an age of 400 Ma by clicking the appropriate line at the line number column 9 Select sub option RECONSTRUCT Bi VGP Reconstruction ul Eli Continent 101 North American YGP Latitude C North Pole YGP Longitude 320 33 Ok Conca Select south pole and click the lt OK gt option Result Continent data already corrected for the opening of the North Atlantic is rotated by an amount which brings the selected reference VGP to the South pole Note that the Euler Rotation Pole reguired to do this will become the current Euler Pole setting which is displayed below the main menu and can be used by option ROTATE CONTINENT to position other continents in a Devonian
28. trol the Velocity option performance The following parameters can be changed updated PARAMETER FUNCTION 26 Page Reference latitude in degrees Palaeolatitudes drift rates and angular velocities Reference longitude in degrees are always calculated with respect to the selected reference locality Start Time in Ma End Time in Ma when End Time window in Ma Invert Latitudes Yes or No VGP 2 Yes Baltica Plot Declination or Latitude error original to INC BI95 APW path spline or Original data Expanded Latitude plot Yes No Amplitude Latitude Plot in Deg Amplitude drift velocity in cm yr Amplitude rotation plot in o Ma Whenever a VGP file is loaded the program tests for minimum start and maximum end age range and the horizontal time axis see Fig 16 is set up accordingly The operator can however change the START and END times after having loaded a VGP file Useful combining several VGP files with different Start and times i e plot at same scale Drift rates and rotational velocities are averaged within the setting of this parameter Dependent on the choice of VGP polarity the operator may have to invert latitude estimates E g file B20092 isa south pole file and Invert Latitudes has to be set to in order to display the latitudinal movements of correctly Set Plot declination to ON when analysing APW paths Use Latitude Error to incl
29. ty index Q grades 1 to 7 least to most reliable It is clear that the angular error associated with a particular palaeomagnetic pole position is far from an adequate description of the quality or reliability of that pole For example uncertainty in the age of the result has a direct bearing on the angular uncertainty which should be associated with it since apparent polar wander might be continuing within the time period of uncertainty Instead of weighting pole positions solely on the basis of criterion 2 in Van der Voo s reliability scheme alfa95 it is informative to weight the data in proportion to their Quality factors This causes the smooth path to pass close to the data which score 7 full marks and be only gently guided by those data with lower reliabilities GENERATION OF APW PATHS APW Path Calculate Edit Spline Fitting Moving Average Voo Grading 9 Timescale 1 Load a VGP file via the main menu option OPEN VGP e g file data VGPs NorthAmerica2008_ROG vgp 2 Select option TABLE VGP 3 Select sub option SPLINE FITTING 20 Page E Generate APWP J ik Si Weighting Smoothing 200 C None 4 According to Q Factor Path Resolution Path Precision According to alfa95 5 5 Output APW File name spline22 Cancel OK NOTE MAXIMUM 150 INPUT POLES FOR SPLINE ANALYSIS 4 Select a No weighting b Weighting according to Q factor c Weighting according to alfa95
30. ude latitude error bars for VGP data calculate error bars from INC H295 Set APW path spline to ON when analysing APW paths Display of latitudinal plot top diagram two times normal size when set to YES Set maximum amplitude 900 lt value gt 0o Set maximum amplitude Value gt 0 cm yr Set amplitude Value gt 0 Deg Ma Amplitude CUM APW in Deg Set amplitude value gt 00 used in option APW rates Amplitude APW rate in cm year used in option APW rates Set amplitude value gt 0 cm yr 27 Page
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