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Geosoft Oasis Montaj Local Datum Transform - What is the purpose of this parameter?


When defining a coordinate system in Oasis Montaj one of the parameters is "Local Datum Transform". Is this the coordinate transformation definition to convert the defined coordinate system of a data set to WGS84 geographic coordinates? It is implied in the help docs but is not specifically stated. Are all OM data sets converted to WGS84 in the "background" based on this parameter?


After posting the question I was able to track down a specific article at Geosoft that answers this. Yes, the "Local Datum Transform" is used to convert to WGS84. https://my.geosoft.com/supportcentre?showOverlay=yes&login=ok#kb/kA230000000VFkoCAG

See Local Datums


GXGUI class¶

These are graphical functions that typically create a dialog-style window for a specific function. Examples include file import wizards, and the Histogram and Scatter tools.

classmethod browse_dir ( title, default, dir_path ) ¶

Browses for a specific directory.

  • title (str) – Title of the Form
  • default (str) – Default path (Can be “”)
  • dir_path (str_ref) – Result Path Buffer (default on input)

Limitations: May not be available while executing a command line program.

classmethod color_form ( col, no_col ) ¶

  • col (int_ref) – Color (modified)
  • no_col (int) – Ask about C_TRANSPARENT if white is selected (1: yes, 0: no)?

Limitations: May not be available while executing a command line program.

Note: Color value is set on input, and new value returned. If the input color type is C_TRANSPARENT , then the color is set to white, if any other type is input the output is guaranteed to be of the same type.

If no_col is 1, then on exit, if white is selected, the user is prompted: ‘Do you want white (Yes) or “None” (No) ?’ and the color is converted as requested. If this is not the case, the C_TRANSPARENT is converted to white (if “Ok” is selected) and no choice is offered.

classmethod color_transform ( itr, st ) ¶

Define an GXITR of up to 8 zones.

0 if OK 1 if user cancels

Limitations: May not be available while executing a command line program.

Note: The statistics object is required in order to determine data ranges, percentiles, etc. Create it using GXST.create_exact , or be sure to enable histogram statistics.

Define an GXITR of up to 12 zones, with file load/save buttons.

  • itr (GXITR) – GXITR object (modified)
  • st (GXST) – GXST object (input)
  • zones (int) – Max number of zones (8 or 12)
  • load_save (int) – Show file load/save buttons (TRUE or FALSE)?
  • file (str_ref) – Default color transform file name

0 if OK 1 if user cancels

Limitations: May not be available while executing a command line program.

Note: The statistics object is required in order to determine data ranges, percentiles, etc. Create it using GXST.create_exact , or be sure to enable histogram statistics. The color transform file name is used as the default when the save button is pushed, and is updated both after the load and save buttons are pushed by the value input or selected by the user.

classmethod coord_sys_wizard ( ipj, editable, mode, source_label, source ) ¶

Launch the coordinate system definition/display GXGUI .

  • ipj (GXIPJ) – GXIPJ object
  • editable (int) – Editable GXIPJ (0:No, 1:Yes)
  • mode (int) – COORDSYS_MODE constants
  • source_label (str) – Data source label
  • source (str) – Data source

Limitations: May not be available while executing a command line program.

Note: Launches the new GX.Net single-dialog coordinate system definition dialog. The input GXIPJ is modified on return if OK is selected (and the editable parameter is 1). The “Data source label” and “Data source” is information displayed in the dialog for the user to know where the GXIPJ came from (e.g. “Grid: X.grd”)

Launch the coordinate system definition/display GXGUI .

  • ipj (GXIPJ) – Original grid GXIPJ object
  • target_ipj (GXIPJ) – Source (target) grid GXIPJ object. This is supplied so the modified orientation can be calculated and displayed.
  • editable (int) – Editable GXIPJ (0:No, 1:Yes)
  • mode (int) – COORDSYS_MODE constants
  • source_label (str) – Data source label
  • source (str) – Data source
  • nx (int) – Number of cells in X
  • ny (int) – Number of cells in Y
  • x0 (float_ref) – Grid orgin X (grid’s own coordinate system)
  • y0 (float_ref) – Grid orgin Y (grid’s own coordinate system)
  • dx (float_ref) – Grid cell size X
  • dy (float_ref) – Grid cell size Y
  • rot (float_ref) – Grid rotation angle (degrees CCW)

Limitations: May not be available while executing a command line program.

Note: Same as coord_sys_wizard_licensed but allows the original grid info to be adjusted when projections on section or oriented plan grids are modified. In the tool, it is the “modified” orientation required to keep the edited projection’s grid in the same location as it was in the target projection.

classmethod coord_sys_wizard_licensed ( ipj, editable, mode, source_label, source ) ¶

Launch the coordinate system definition/display GXGUI .

  • ipj (GXIPJ) – GXIPJ object
  • editable (int) – Editable GXIPJ (0:No, 1:Yes)
  • mode (int) – COORDSYS_MODE constants
  • source_label (str) – Data source label
  • source (str) – Data source

Limitations: May not be available while executing a command line program.

Note: Same as coord_sys_wizard_licensed but will always be editable. The other method is not editable in the viewer while this one is.

classmethod create_wnd_from_hwnd ( p1 ) ¶

Create a standard WND object from an HWND.

Parameters:p1 (int) – HWND Handle
Returns:x - WND object created
Return type:int

Limitations: May not be available while executing a command line program.

Note: The object returned must be destroyed by the destroy object call.

classmethod cumulative_percent ( file, itr ) ¶

Define a percent-based GXITR of up to 12 zones.

  • file (str_ref) – Default color transform file name
  • itr (GXITR) – GXITR object (returned)

0 if OK 1 if user cancels

Limitations: May not be available while executing a command line program.

Note: The GXITR values are interpreted as cumulative percent values, using the “PERCENT=1” value in the GXITR ‘s GXREG .

Note that processes using ITRs do not automatically know to convert between percent values and “actual” data values. The GXREG “PERCENT” value is simply a flag to indicate to a user that the values are intended to be in the range from 0 < x < 100. The GXITR should not, therefore, be applied directly to data unless that data is already given in percent.

If the file name is defined on input, the initial GXITR will be loaded from it. If it is left blank, a default 5-color transform with The color transform file name is used as the default when the save button is pushed, and is updated both after the load and save buttons are pushed by the value input or selected by the user.

classmethod custom_file_form ( title, filter, default, file_path, type, multi ) ¶

General file Open/Save Form for Multiple/Single file selections and custom filter capability

  • title (str) – Title of the Form
  • filter (str) – Custom filter.
  • default (str) – Default value
  • file_path (str_ref) – Where the file name(s) is returned
  • type (int) – FILE_FORM constants
  • multi (int) – Allow Multiple file selections = TRUE Single file selections = FALSE

Limitations: May not be available while executing a command line program.

Note: Remember to make the string size big enough for multiple file selections. In the case of multiple selections the names will be separated by a semicolon and only the first file will contain the full path.

classmethod dat_file_form ( title, default, psz_file_path, type, validation_type, multi ) ¶

Grid and Image file Open/Save Form for Multiple/Single file selections

  • title (str) – Title of the Form
  • default (str) – Default value
  • psz_file_path (str_ref) – Where the file name(s) is returned
  • type (int) – DAT_TYPE constants
  • validation_type (int) – FILE_FORM constants
  • multi (int) – Allow Multiple file selections = TRUE Single file selections = FALSE

Limitations: May not be available while executing a command line program.

Note: Remember to make the string size big enough for multiple file selections. In the case of multiple selections the names will be separated by a semicolon and only the first file will contain the full path.

When using the multiple flag on any of these functions please be aware that the string returned will be in the format: drive:path1path2name.grid|name2.grid|name3.grid(QUALIFIERS) All grids are required to be of the same type.

classmethod database_type ( name, type ) ¶

Returns the type string of an external DAO database.

0 - OK -1 - Cancel terminates on error

Limitations: May not be available while executing a command line program.

Note: If the file extension is “mdb”, then an MSJET (Microsoft Access) database is assumed. If the file name is “ODBC”, then “ODBC” is returned as the type. Otherwise, a dialog appears listing the other valid DAO database types.

classmethod datamine_type ( file, type ) ¶

Returns the type of a Datamine file.

Parameters:file (str) – File Name (for display purposes only)
Returns:0 - OK -1 - Cancel
Return type:int

Limitations: May not be available while executing a command line program.

Note: Often, a Datamine file can be opened a number of different ways (e.g. as a string file or a as wireframe (point) file. The following function checks to see if there is a choice to be made between types supported by Geosoft for import. If not, it just returns the original type “hint” from Datamine. If there is a choice, it puts up a dialog with the choices for the user to pick from. Do a bit-wise AND with the returned type to determine the file type (or the type selected).

Currently supported overlapping types/choices:

classmethod export_xyz_template_editor ( db, template, size ) ¶

Allows the user to edit XYZ export template using a complex dialog. The Template name may change during editing.

  • db (GXDB) – Database
  • template (str) – Name of the Template (can change)
  • size (int) – Size of the Template

Limitations: May not be available while executing a command line program.

Note: Only uses the current GXDB . This function does not exactly work as supposed to. Instead of using the GXEDB handle passed to it, it only will use the current GXDB . Please see ExportXYXTemplateEditorEx_GUI for an updated function.

classmethod export_xyz_template_editor_ex ( edb, template ) ¶

Allows the user to edit an XYZ export template using a complex dialog. The template name may change during editing.

Limitations: May not be available while executing a command line program.

classmethod fft2_spec_filter ( spec_file_name, con_file_name ) ¶

Interactive GXFFT2 radially averaged power spectrum filter

  • spec_file_name (str) – Name of the input spectrum file
  • con_file_name (str) – Name of the output control file

Limitations: May not be available while executing a command line program.

classmethod file_filter_index ( filter ) ¶

Return the FILE_FILTER_XXX value for a file filter string.

Parameters:filter (str) – Input filter string
Returns: FILE_FILTER constants , -1 if not found
Return type:int

Note: For example, if “Database ( *.gdb )” is input, then the FILE_FILTER_GDB value is returned.

classmethod gcs_datum_warning_shp ( data_source, ipj ) ¶

Launch the GCS Datum Warning dialog for GXSHP files.

Note: Runs the GCS Warning dialog with one data source

classmethod gcs_datum_warning_shp_ex ( source_lst, datum_from_lst, ldtlst, mview ) ¶

Launch the GCS Datum Warning dialog for GXSHP files.

  • source_lst (GXLST) – Data source names
  • datum_from_lst (GXLST) – Corresponding datum names
  • ldtlst (GXLST) – Returned corresponding LDT names

Note: Runs the GCS Warning dialog with multiple data sources

classmethod gcs_datum_warning_shpdb_ex ( source_lst, datum_from_lst, ldtlst, db ) ¶

Launch the GCS Datum Warning dialog for GXSHP files (Database).

  • source_lst (GXLST) – Data source names
  • datum_from_lst (GXLST) – Corresponding datum names
  • ldtlst (GXLST) – Returned corresponding LDT names

Note: Runs the GCS Warning dialog with multiple data sources (Database)

General file Open/Save Form for Multiple/Single file selections and multiple filter capability

  • title (str) – Title of the Form
  • filt_vv (GXVV) – INT GXVV of file filters to use FILE_FILTER constants The first one is default, can pass ( GXVV ) 0 for to use next parameter.
  • filter (int) – FILE_FILTER constants (ignored if parameter above is not zero)
  • default (str) – Default value
  • file_path (str_ref) – Where the file name(s) is returned
  • type (int) – FILE_FORM constants
  • multi (int) – Allow Multiple file selections = TRUE Single file selections = FALSE

Limitations: May not be available while executing a command line program.

Note: Remember to make the string size big enough for multiple file selections. In the case of multiple selections the names will be separated by a semicolon and only the first file will contain the full path.

Defined Functions The following four functions are handy defines and simply pass the appropriate parameter.

iFileOpen_GUI iFileSave_GUI iMultiFileOpen_GUI iMultiFileSave_GUI

Get the current area of interest from the application.

  • min_x (float_ref) – AOI Area Min X
  • min_y (float_ref) – AOI Area Min Y
  • max_x (float_ref) – AOI Area Max X
  • max_y (float_ref) – AOI Area Max y
  • ply (GXPLY) – AOI Bounding GXPLY (Filled if available, otherwise empty)
  • ipj (GXIPJ) – AOI Bounding GXIPJ

Limitations: May not be available while executing a command line program.

Note: Depending on what is currently visible on screen and the defined coordinate system the user may be prompted by a warning and optionaly cancel the process.

Get the current area of interest from the application in 3D.

  • min_x (float_ref) – AOI Area Min X
  • min_y (float_ref) – AOI Area Min Y
  • min_z (float_ref) – AOI Area Min Z
  • max_x (float_ref) – AOI Area Max X
  • max_y (float_ref) – AOI Area Max y
  • max_z (float_ref) – AOI Area Max Z
  • ply (GXPLY) – AOI Bounding GXPLY (Filled if available, otherwise empty)
  • ipj (GXIPJ) – AOI Bounding GXIPJ

Limitations: May not be available while executing a command line program.

Note: Depending on what is currently visible on screen and the defined coordinate system the user may be prompted by a warning and optionaly cancel the process.

classmethod get_client_window_area ( min_x, min_y, max_x, max_y ) ¶

Get the location of the Oasis montaj client window.

  • min_x (int_ref) – X Min returned (0)
  • min_y (int_ref) – Y Min returned (0)
  • max_x (int_ref) – X Max returned (width)
  • max_y (int_ref) – Y Max returned (height)

Limitations: May not be available while executing a command line program.

Note: Returns the coordinates of the client window area (where MDI document windows are placed). The returned coordinates are 0,0 for the minimum X and Y and the window width width and height for the maximum X and Y.

Return the user default extension and qualifier for grids/images.

  • flags (int) – DAT_TYPE constants
  • open (int) – FILE_FORM constants
  • ext (str_ref) – Returned default extension (e.g. “grd”)
  • qual (str_ref) – Returned default qualifier (e.g. “GRD”)

Note: The default grid/image filters are normally stored in “MONTAJ.DEFAULT_XGD_IN” and “MONTAJ.DEFAULT_XGD_OUT”

If no filter is defined, or the filter is not found then “grd” and “GRD” are returned as the default extension and qualifier.

classmethod get_file_filter ( file_filter, filter, mask, ext, path ) ¶

Return the defined filter, mask, extension and directory for an input filter.

  • file_filter (int) – FILE_FILTER constants
  • filter (str_ref) – Returned file filter string
  • mask (str_ref) – Returned file mask string
  • ext (str_ref) – Returned file extension
  • path (int_ref) – GS_DIRECTORY constants Returned directory.

Note: Returns the four parts of the file filter e.g. for FILE_FILTER_GDB it returns:

This function is useful for constuction open/save dialog file filters, especially in GX.Net functions.

classmethod get_gs_directory ( path, dir ) ¶

Return the directory path for value of GS_DIRECTORY constants .

  • path (int) – GS_DIRECTORY constants Returned directory.
  • dir (str_ref) – Returned directory path

Note: Works along with the get_file_filter function. Note that most values of FILE_FILTER_XXX will return GS_DIRECTORY_NONE , and give the current workspace directory.

This function is useful for constuction open/save dialog file filters, especially in GX.Net functions.

Get the current parent window

Returns:Parent window.
Return type:int

Limitations: May not be available while executing a command line program.

classmethod get_printer_lst ( lst ) ¶

Gets a list of all printers.

Parameters:lst (GXLST) – List to place into

Limitations: May not be available while executing a command line program.

Get the Oasis montaj window’s position state

  • left (int_ref) – Window left position
  • top (int_ref) – Window top position
  • right (int_ref) – Window right position
  • bottom (int_ref) – Window bottom position
  • state (int_ref) – Window state WINDOW_STATE constants

Limitations: May not be available while executing a command line program.

Retrieve the current state of the Oasis montaj window

Returns: WINDOW_STATE constants
Return type:int

Limitations: May not be available while executing a command line program.

classmethod grid_stat_hist ( grid_name ) ¶

Display Histogram of grid

Parameters:grid_name (str) – Name of the grid to get stats from

Limitations: May not be available while executing a command line program.

classmethod import_ascii_wizard ( name, temp ) ¶

Generate a template file from a gui.

Limitations: May not be available while executing a command line program.

classmethod import_chem_database ( name, temp, table, type ) ¶

Generate a template file for importing Geochems Database.

  • name (str) – Data file name
  • temp (str) – Template to make
  • table (str_ref) – Name of table
  • type (int) – IMPCH_TYPE constants

Limitations: May not be available while executing a command line program.

classmethod import_chem_database_ado ( connect, temp, table, type ) ¶

Improved template creation for importing geochem database (ADO).

  • connect (str) – External database connection string (Blank for OLEDB Wizard)
  • temp (str) – Template to make
  • table (str_ref) – Name of table
  • type (int) – IMPCH_TYPE constants

Limitations: May not be available while executing a command line program.

Note: This is an improved version of ImportChemDatabase_GUI using the new ADO technology, as opposed to DAO. Use in conjuction with GXDU.import_ado . See also ImportDatabaseADO_GUI.

classmethod import_chem_wizard ( name, temp, type ) ¶

Generate a template file for importing geochems.

  • name (str) – Data file name
  • temp (str) – Template to make
  • type (int) – IMPCH_TYPE constants

Limitations: May not be available while executing a command line program.

classmethod import_database ( name, temp, table ) ¶

Create template to import an external database table.

  • name (str) – External database file name
  • temp (str) – Template to make
  • table (str_ref) – Name of table imported (returned)

Limitations: May not be available while executing a command line program.

Note: This is used to select a single database table, and selected fields from that table. If the database is not Microsoft Access (type .mdb), an introductory dialog requests the file type. This function DOES NOT import the table itself, but creates an import template which may be used to import the table (see GXDU.import_dao ).

classmethod import_database_ado ( connect, temp, table ) ¶

Create template to import an external database table (ADO Version).

  • connect (str) – External database connection string (Blank for OLEDB Wizard)
  • temp (str) – Template to make
  • table (str_ref) – Name of table imported (returned)

Limitations: May not be available while executing a command line program.

  1. This function DOES NOT import the table itself, but creates an import template which may be used to import the table (see GXDU.import_ado ).
  2. If connection string is of type “FILENAME=. ” the connection will attempt to resolve it as a file database. (see also ODBCFileConnect_GUI)

Create template to import an external database table, created using SQL.

  • name (str) – External database file name
  • sql (str) – Text file with SQL queries to use, (“” - get from database)
  • temp (str) – Import template to make
  • line (str_ref) – Name of table imported (returned)

Limitations: May not be available while executing a command line program.

Note: 1. This is used to build an Oasis montaj group (line) from

one or more database tables and fields, by selecting from one or more SQL selection queries. The list of queries is read from a text file with the following syntax:

Query_Name_1 Query. Query. (continued) . . END_QUERY Query_Name_2 etc.

  1. Each query has a title line, the query itself, then the “END_QUERY” line to finish. The title of a subsequent query is on the line after an “END_QUERY” line.
  2. If the text file parameter is left blank (“”), then selection queries in the database itself are listed. In addition to the pre-defined queries, there is a “User Defined” query which may be filled in by the user.
  3. This function DOES NOT import the table itself, but creates an import template which may be used to import the data (see GXDU.import_dao ).
  4. If connection string is of type “FILENAME=. ” the connection will attempt to resolve it as a file database. (see also ODBCFileConnect_GUI)

Create template to import an external database table, created using SQL (New ADO Version).

  • connect (str) – External database connection string (Blank for OLEDB Wizard)
  • sql (str) – Text file with SQL queries to use, (“” - get from database)
  • temp (str) – Import template to make
  • line (str_ref) – Name of table imported (returned)

Limitations: May not be available while executing a command line program.

Note: This is used to build an Oasis montaj group (line) from one or more database tables and fields, by selecting from one or more SQL selection queries. The list of queries is read from a text file with the following syntax:

Query_Name_1 Query. Query. (continued) . . END_QUERY Query_Name_2 etc.

Each query has a title line, the query itself, then the “END_QUERY” line to finish. The title of a subsequent query is on the line after an “END_QUERY” line.

If the text file parameter is left blank (“”), then selection queries in the database itself are listed. In addition to the pre-defined queries, there is a “User Defined” query which may be filled in by the user.

This function DOES NOT import the table itself, but creates an import template which may be used to import the data (see GXDU.import_dao ).

classmethod import_drill_database_ado ( connect, temp, table, type, reg ) ¶

Generate a template file for importing drill holes.

  • connect (str) – External database connection string (Blank for OLEDB Wizard)
  • temp (str) – Template to make
  • table (str_ref) – Name of table
  • type (int_ref) – Type of import returned DH_DATA constants
  • reg (GXREG) – Drill Hole Object GXREG handle

Limitations: May not be available while executing a command line program.

Note: This is an improved version of ImportDrillDatabase_GUI using the new ADO technology, as opposed to DAO. Use in conjunction with GXDU.import_ado . See also ImportDatabaseADO_GUI.

classmethod import_drill_database_ado2 ( connect, temp, table, type, reg ) ¶

Same as import_drill_database_ado , but template name is returned.

  • connect (str) – External database connection string (Blank for OLEDB Wizard)
  • temp (str_ref) – Template to make (if left blank, the created template name is returned)
  • table (str_ref) – Name of table
  • type (int_ref) – Type of import returned DH_DATA constants
  • reg (GXREG) – Drill Hole Object GXREG handle

Limitations: May not be available while executing a command line program.

Note: If it is not defined on input, the template name is set to be the Wholeplot table name e.g. “HOLESURVEY.i4” for “Project_HOLESURVEY”

classmethod import_drill_database_esri ( connect, temp, table, type, geochem, reg ) ¶

Same as iImportDrillDatabaseADO2_GUI, but from an ArcGIS Geodatabase

  • connect (str) – External database connection string (e.g. “d:Personaltest.mdb|Table” or “d:Filetest.gdb|TableX|FeatureClassY)”
  • temp (str_ref) – Template to make (if left blank, the created template name is returned)
  • table (str_ref) – Name of table
  • type (int_ref) – Type of import returned DH_DATA constants
  • geochem (bool) – Geosoft Geochemistry Database?
  • reg (GXREG) – Drill Hole Object GXREG handle

Limitations: May not be available while executing a command line program.

Note: If it is not defined on input, the template name is set to be the Wholeplot table name e.g. “HOLESURVEY.i4” for “Project_HOLESURVEY”

classmethod import_drill_database_odbc ( connect, temp, table, type, reg ) ¶

Generate a template file for importing drill holes from ODBC database data.

  • connect (str_ref) – Connection string
  • temp (str_ref) – Template to make
  • table (str_ref) – Name of table
  • type (int_ref) – Type of import returned DH_DATA constants
  • reg (GXREG) – Drill Hole Object GXREG handle

Limitations: May not be available while executing a command line program.

Note: If the input connection string is empty (“”), then the ODBC connection dialogs will appear (e.g. to connect to a machine database) before the import wizard is run. The connect string used for this connection is then returned. This string can then be used on input to skip the ODBC connection dialogs and go straight to the Wholeplot import wizard. Because the name of the database is not necessarily known, the template name is created from the name of the table opened - e.g. “HOLELOCATION.i4”.

classmethod import_drill_database_odbc_maxwell ( connect, temp, table, type, reg ) ¶

Same as import_drill_database_odbc but customized for Maxwell.

  • connect (str_ref) – Connection string
  • temp (str_ref) – Template to make
  • table (str_ref) – Name of table
  • type (int_ref) – Type of import returned DH_DATA constants
  • reg (GXREG) – Drill Hole Object GXREG handle

Limitations: May not be available while executing a command line program.

Note: Same as import_drill_database_odbc but customized for Maxwell.

Generate a template file for importing drill holes.

  • name (str) – Data file name
  • temp (str) – Template to make
  • table (str_ref) – Name of table
  • type (int_ref) – Type of import returned DH_DATA constants
  • reg (GXREG) – Drill Hole Object GXREG handle

Limitations: May not be available while executing a command line program.

Create template to import an external database table provide query.

  • name (str) – External database file name
  • temp (str) – Import template to make
  • sql (str) – SQL selection query to run on database
  • line (str) – Name of Oasis table to create

0 - OK -1 Cancel terminates on error

Limitations: May not be available while executing a command line program.

Note: This is similar to import_database_sql , but dispenses with the dialog offering a selection of queries. Instead, the user supplies the query as a string.

This function DOES NOT import the table itself, but creates an import template which may be used to import the data (see GXDU.import_dao ).

classmethod import_template_sqlado ( name, temp, sql, line ) ¶

Create template to import an external database table provide query.

  • name (str) – External database connection string (Blank for OLEDB Wizard)
  • temp (str) – Import template to make
  • sql (str) – SQL selection query to run on database
  • line (str) – Name of Oasis table to create

0 - OK -1 - Cancel terminates on error

Limitations: May not be available while executing a command line program.

Note: This is similar to import_database_sql , but dispenses with the dialog offering a selection of queries. Instead, the user supplies the query as a string.

This function DOES NOT import the table itself, but creates an import template which may be used to import the data (see GXDU.import_ado ).

classmethod import_xyz_template_editor ( db, template, size, file ) ¶

Allows the user to edit XYZ import templates using a complex dialog. The Template name may change during editing.

  • db (GXDB) – Database
  • template (str) – Name of the Template (can change)
  • size (int) – Size of the Template
  • file (str) – Name of the XYZ file to base it on

Limitations: May not be available while executing a command line program.

Change the Internet Trust Relationships

Limitations: May not be available while executing a command line program.

Check if this is a null (undefined) instance

Returns:True if this is a null (undefined) instance, False otherwise.
Return type:bool
classmethod launch_geo_dotnetx_tool ( dll, func, meta ) ¶

Launch a user created .Net GEOXTOOL.

  • dll (str) – Assembly name
  • func (str) – Control Class Name
  • meta (GXMETA) – GXMETA Handle (holding tool configuration data)

Limitations: May not be available while executing a command line program.

Launch a user created .Net GEOXTOOL.

  • dll (str) – Assembly name
  • func (str) – Control Class Name
  • meta (GXMETA) – GXMETA Handle (holding tool configuration data)
  • align (int) – XTOOL_ALIGN constants (can specify one or more or XTOOL_ALIGN_ANY )
  • dock (int) – XTOOL_DOCK constants
  • width (int) – Default width
  • height (int) – Default height

Limitations: May not be available while executing a command line program.

classmethod launch_geo_x_tool ( dll, func, meta ) ¶

Launch a user created GEOXTOOL.

  • dll (str) – DLL name
  • func (str) – Function Name
  • meta (GXMETA) – GXMETA Handle (holding tool configuration data)

Limitations: May not be available while executing a command line program.

Launch a user created GEOXTOOL.

  • dll (str) – DLL name
  • func (str) – Function Name
  • meta (GXMETA) – GXMETA Handle (holding tool configuration data)
  • align (int) – XTOOL_ALIGN constants (can specify one or more or XTOOL_ALIGN_ANY )
  • dock (int) – XTOOL_DOCK constants
  • width (int) – Default width
  • height (int) – Default height

Limitations: May not be available while executing a command line program.

classmethod launch_single_geo_dotnetx_tool ( dll, func, meta ) ¶

Launch a user created .Net GEOXTOOL ensuring a single instance.

  • dll (str) – Assembly name
  • func (str) – Control Class Name
  • meta (GXMETA) – GXMETA Handle (holding tool configuration data)

Limitations: May not be available while executing a command line program.

classmethod launch_single_geo_dotnetx_tool_ex ( dll, func, meta, align, dock, width, height ) ¶

Launch a user created .Net GEOXTOOL ensuring a single instance.

  • dll (str) – Assembly name
  • func (str) – Control Class Name
  • meta (GXMETA) – GXMETA Handle (holding tool configuration data)
  • align (int) – XTOOL_ALIGN constants (can specify one or more or XTOOL_ALIGN_ANY )
  • dock (int) – XTOOL_DOCK constants
  • width (int) – Default width
  • height (int) – Default height

Limitations: May not be available while executing a command line program.

classmethod line_pattern_form ( pattern, thickness, pitch, colour ) ¶

  • pattern (int_ref) – Current Pattern
  • thickness (float_ref) – Current Thickness
  • pitch (float_ref) – Current Pitch
  • colour (int_ref) – Current Pattern Color

Limitations: May not be available while executing a command line program.

Note: Same as pattern_form but for line patterns.

classmethod meta_data_tool ( meta, root_token, schema ) ¶

  • meta (GXMETA) – Meta object
  • root_token (int) – Root Token, H_META_INVALID_TOKEN for root
  • schema (int) – Display schema information ?

Limitations: May not be available while executing a command line program.

classmethod meta_data_viewer ( meta, root_token, schema ) ¶

  • meta (GXMETA) – Meta object
  • root_token (int) – Root token, H_META_INVALID_TOKEN for root
  • schema (int) – Display schema information ?

Limitations: May not be available while executing a command line program.

A null (undefined) instance of GXGUI

Returns:A null GXGUI
Return type:GXGUI
classmethod odbc_file_connect ( file, connect, usage, table ) ¶

Get the connection string for a file database as well as optional table name and FileUsage attribute

  • file (str) – File Name
  • connect (str_ref) – Connection string (returned)
  • usage (int) – File Usage (0 - ODBC drivers not queried, 1 - Directory containing tables, 2 - File containing tables)
  • table (str_ref) – Table name of file (returned if plUsage==1)

0 - OK -1 - Cancel terminates on error

Limitations: May not be available while executing a command line program.

Note: If the file extension is “mdb” or “xls” then a Microsoft Access or Excel database is assumed. Otherwise, a dialog appears listing the installed ODBC file database drivers. If the driver takes a directory as a database (FileUsage==1) the table name is also returned. This is needed because the table name may or may not include the file extension.

  • Select a pattern.
  • pat (int_ref) – Current Pattern
  • size (float_ref) – Current Size, // returned
  • thick (int_ref) – Current Thick (0-100) // returned
  • dense (float_ref) – Current Density, // returned
  • col (int_ref) – Current Pattern Color // passed in and returned
  • back_col (int_ref) – Current Background Color // passed in and returned can be C_TRANSPARENT

Limitations: May not be available while executing a command line program.

Note: Pattern values set on input, and new values returned. Solid fill is indicated by Pattern number 0.

Returned Values (not set on input)

Size pattern tile size in mm. Thick pattern line thickness in percent of the tile size. valid range is 0-100. Density Tile spacing. A value of 1 means tiles are laid with no overlap. A value of 2 means they overlap each other.

The pattern Angle and Style parameters are not user-definable.

classmethod print_file ( file ) ¶

Prints a file to current printer

Parameters:file (str) – Filename string

Limitations: May not be available while executing a command line program.

  • hdc (int) – DC Handle
  • left (int) – Left value of the render rect in Windows coordinates (bottom>top)
  • bottom (int) – Bottom value
  • right (int) – Right value
  • top (int) – Top value
  • pattern (int) – Pattern number
  • thickness (float) – Pattern thickness
  • pitch (float) – Pattern pitch
  • col (int) – Pattern color
  • is_enabled (int) – Is this window enabled?
  • is_button (int) – Is this a button?
  • is_selected (int) – Is this window selected?

Limitations: May not be available while executing a command line program.

Note: Same as render_pattern but for line patterns.

  • Render a pattern.
  • hdc (int) – DC handle
  • left (int) – Left value of the render rect in Windows coordinates (bottom>top)
  • bottom (int) – Bottom value
  • right (int) – Right value
  • top (int) – Top value
  • pat (int) – Pattern number
  • size (float) – Pattern size, // input GS_R8DM to use default
  • thick (int) – Pattern thick (0-100) // input GS_S4DM to use default
  • dense (float) – Pattern density, // input GS_R8DM to use default
  • col (int) – Pattern color // input GS_S4DM to use default
  • back_col (int) – Pattern background color // input GS_S4DM to use default can be C_TRANSPARENT
  • is_enabled (int) – Is this window enabled?
  • is_button (int) – Is this a button?
  • is_selected (int) – Is this window selected?

Limitations: May not be available while executing a command line program.

Note: Renders a Geosoft pattern to a Windows DC.

classmethod set_parent_wnd ( wnd ) ¶

Set the current parent WND

Parameters:wnd (int) – New Parent Window

Limitations: May not be available while executing a command line program.

Note: The parent WND is used by all modal dialogs as a parent to ensure the dialog is correctly modal.

classmethod set_printer ( printer ) ¶

Parameters:printer (str) – Printer Name

Limitations: May not be available while executing a command line program.

classmethod set_prog_always_on ( on ) ¶

Ability to set the progress bar to stay visible even if main application is processing messages

Parameters:on (bool) – Should progress bar remain visible

Limitations: May not be available while executing a command line program.

Note: In montaj the progress bar is hidden when the main window start processing messages. This is not always desirable in some 3rd party apps, hence this function.

Get the Oasis montaj window’s position and state

  • left (int) – Window left position
  • top (int) – Window top position
  • right (int) – Window right position
  • bottom (int) – Window bottom position
  • state (int) – Window state WINDOW_STATE constants

Limitations: May not be available while executing a command line program.

classmethod set_window_state ( state ) ¶

Changes the state of the Oasis montaj window

Parameters:state (int) – WINDOW_STATE constants

Limitations: May not be available while executing a command line program.

classmethod show_3d_viewer_dialog ( title, o3dv ) ¶

Display a standalone 3D viewer

Limitations: May not be available while executing a command line program.

Note: Any changes made to the 3D View will be persisted.

Display histogram of data directly

  • min (float) – Min Value to display
  • max (float) – Max Value to display
  • mean (float) – Mean Value to display
  • std_dev (float) – StdDev Value to display
  • median (float) – Median Value to display
  • items (int) – Items Number of items this comprises
  • vv (GXVV) – GXVV holding hist counts

Limitations: May not be available while executing a command line program.

classmethod show_hist ( st ) ¶

Display Histogram of data from GXST

Parameters:st (GXST) – Statistics obj

Limitations: May not be available while executing a command line program.

classmethod simple_map_dialog ( map, title, help_id ) ¶

General purpose map display GXGUI with no interaction.

  • map (GXMAP) – GXMAP object
  • title (str) – Title
  • help_id (str) – HelpID

Limitations: May not be available while executing a command line program.

Note: This function displays a map in a simple resizable dialog that fits the map into it. It is generally useful to display temporary maps as graphs (e.g. variograms).

  • Select a symbol.
  • symb_font (str_ref) – Symbol font file name
  • geo_font (bool_ref) – Geosoft font?
  • weight (int_ref) – Weight MVIEW_FONT_WEIGHT constants
  • symb_num (int_ref) – Symbol number
  • symb_size (float_ref) – Symbol size
  • symb_ang (float_ref) – Symbol angle
  • edge_col (int_ref) – Edge color
  • fill_col (int_ref) – Fill color

Limitations: May not be available while executing a command line program.

Note: Symbols are set on input, and new values returned.

classmethod thematic_voxel_info ( vox ) ¶

Display GX.Net thematic voxel info GXGUI .

Parameters:vox (GXVOX) – GXVOX object

Limitations: May not be available while executing a command line program.

Note: Displays the thematic voxel codes, colors, total volume for each code, and number of valid items (cubes) for each code. This is a replacement for the numeric stats done on normal numerical voxel grids.

classmethod two_panel_selection ( ls_tf, ls_ts, title ) ¶

General purpose two-panel selection.

  • ls_tf (GXLST) – All available items for selection.
  • ls_ts (GXLST) – Selections (altered on output)
  • title (str) – Title for dialog

Limitations: May not be available while executing a command line program.

Note: Takes as input two LSTs, one contains all available items, the second currently selected items. These are processed, and in the left panel are displayed all items in the first GXLST not in the selection GXLST , and on the right all items in the first GXLST which are in the selection GXLST . (Items in the selection GXLST NOT in the first GXLST are ignored). Once the user has finalized the selections, the final selections are returned in the selection GXLST .

Selections and display are based on the LST_ITEM_NAME part of the GXLST item, but on export both the LST_ITEM_NAME and LST_ITEM_VALUE elements of the selected items from the first GXLST are transferred to the second list for output.

The sConvertToCSV_LST and sConvertFromCSV_LST functions in lst.h can be used to convert the selection LSTs to forms that can be stored and retrieved from GX parameters (or GXREG or INI, etc.).

classmethod two_panel_selection2 ( ls_tf, ls_ts, title ) ¶

Two-panel selection, items not sorted alphabetically.

  • ls_tf (GXLST) – All available items for selection.
  • ls_ts (GXLST) – Selections (altered on output)
  • title (str) – Title for dialog

Limitations: May not be available while executing a command line program.

Note: Same as two_panel_selection , but the items in the two lists are not sorted alphabetically, but are ordered exactly as input, and when an item is selected it is added at the end of the lists.

classmethod two_panel_selection_ex ( ls_tf, ls_ts, sorted, allow_no_select, title ) ¶

Two-panel selection options for sort and ability to select no items.

  • ls_tf (GXLST) – All available items for selection.
  • ls_ts (GXLST) – Selections (altered on output)
  • sorted (int) – Sort items alphabetically (0:No, 1:Yes)
  • allow_no_select (int) – Allow no items selected (0:No, 1:Yes)
  • title (str) – Title for dialog

Limitations: May not be available while executing a command line program.

Note: Same as two_panel_selection , but the items in the two lists are not sorted alphabetically, but are ordered exactly as input, and when an item is selected it is added at the end of the lists.

classmethod two_panel_selection_ex2 ( ls_tf, ls_ts, sorted, allow_no_select, title, help ) ¶

Two-panel selection extended options including a help link.

  • ls_tf (GXLST) – All available items for selection.
  • ls_ts (GXLST) – Selections (altered on output)
  • sorted (int) – Sort items alphabetically (0:No, 1:Yes)
  • allow_no_select (int) – Allow no items selected (0:No, 1:Yes)
  • title (str) – Title for dialog
  • help (str) – Help link

Limitations: May not be available while executing a command line program.

Note: Same as two_panel_selection_ex , but user can specify a help link.

classmethod voxel_stat_hist ( vox_name ) ¶

Display Histogram of Voxel

Parameters:vox_name (str) – Name of the Voxel to get stats from

Limitations: May not be available while executing a command line program.


Impact of subsurface structures on groundwater exploration using aeromagnetic and geoelectrical data: a case study at Aswan City, Egypt

Geological evaluation and groundwater assessment, especially in arid areas, are considerable targets for constructing recent and sustainable development communities. The current work aims to apply an integrated approach to acquire geologic structures and groundwater potentiality at highly deformed area. As a case study, remote sensing (RS), aeromagnetic, and geoelectrical data are conducted to delineate the subsurface structures and hydrogeological regime at Aswan City. Initially, remote sensing data with GIS software are utilized to delineate the surface structures and watershed configuration. Moreover, the reduced to magnetic pole (RTP) aeromagnetic data is processed and interpreted using appropriate filters. In an attempt to demonstrate the subsurface structures and basement relief maps, the RTP map was analyzed considering the RS data which was stated in previous stage. In the light of RTP aeromagnetic results and well logging data, the direct current resistivity (DCR) sounding is executed particularly along paleochannel and flood plain portion. Due to the inversion process problem of DCR field data, advanced solutions and algorithms are applied to improve the property of the results. Based upon overall results mentioned above, the correlation between subsurface structures and aquifer formation can be monitored. The present approach can be applied for groundwater exploration in this and other similar geological and hydrogeological environments around the world.

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Abstract

Study region

The Motloutse Watershed is located in eastern Botswana.

Study Focus

This study investigates the spatial distribution of recharge in the semi-arid watershed using Weighted Overlay Analysis.

The overuse of groundwater in the Motloutse catchment to support domestic and industrial expansion has generated the need for the determination of areas where renewable storage to groundwater may occur. A select of parameters known to have influence on recharge were considered for input into the analytic process and included lithology, lineament density, ground slope, soil type, soil thickness, and drainage density. A thematic map for each parameter was prepared, reclassified into high, moderate and low potential for recharge. Analytic Hierarchy Process was applied to rank the importance of each parameter relative to one another concerning groundwater recharge. Potential groundwater recharge sites were delineated using Weighted Overlay tool of ArcGIS software.

New Hydrological Insights for the Region

High recharge sites cover 8% of the catchment and correspond to places underlain by sandstones and fractured basaltic outcrops as well as areas covered by thick sandy soils. Moderate recharge occurs in 78 % and low recharge in 14 % of the catchment area. The results from this study are useful for selecting areas for more focused studies on recharge and also form a significant decision support tool for sustainable and equitable utilization of groundwater resources within the Motloutse catchment.


Analysis of aeromagnetic data for interpretation of seismicity at Fayoum-Cairo area, Egypt.

Studying the structure of Fayoum-Cairo area has become significant as the basement and its fraction played the main role in the seismic activity constructing the geological framework of southern Egypt. The magnetic method is believed to be efficient in this respect (Hassoup, et al., 2009), so the magnetic exploration has been preformed aiming to find out the subsurface structures set up at the Dahshour area. This area lies between the Latitudes 28[degrees]8 and 30[degrees]00 N and Longitudes 30[degrees]4 and 32[degrees]00 E in Egypt (Fig. 1). It is generally characterized by surface sedimentary rocks that can physiographically be divided into three main units: the Qarun lake, the plains of ancient terraces, and the plateau surface with irregular scarped faces. The Qarun-lake and its surrounding cultivated lands cover the major part of the Fayoum depression. There exist beach terraces of different levels and widths around the Qarun-lake which extend till the scarpment of Qattrani hill (353 m). This area is structurally controlled by a set of normal faults having long periods of growth and some of these faults manifest strike-slip movements. Deep drilling in the northern part of the Western Desert has exhibited large numbers of swells and basins (Said, 1990).

Meshref (1990) states that the basement rocks in the Western Desert of Egypt have been affected by the oldest E-W and ENE trending faults which in turn intersect with the younger NW and NNW trending faults. These two fault systems have large vertical and horizontal displacements. The Dahshour-Qattrani area is particularly affected by the NW and E-W-trending faults. The NW-trending fault, called the Qattrani fault, has a throw of about 350 m. Elowever, the E-W trending fault, called the G. Sheeb fault, has a throw between 150 and 200 m. The Oligocene basalt occupies these two faults.

On the basis of geophysical data (i.e., seismic and gravity data), Abu El-Ata (1990), outlined three structural heights and two low:

1- The Abu Roash high that strikes in the N-NE-S-SW and E-NE- W-SW directions.

2- El-Sagha height which is oriented into NW-SE directions.

3- The El-Faras-El-Fayoum height, which is oriented in E-NE-W- SW and N-NW-S-SW directions.

Ghazala (2001) concluded that four significant tectonic zones characterize this area: the graben of Nile Valley, the uplift at the East Nile Valley, the Ginidi basin and the Kattaniya uplift. The study of the subsurface structure of the Fayoum-Cairo area is significant to understand relationship between the basement, its fraction and seismic activities at the area.

The Dahshour area is highly deformed with fault systems into different directions (Said 1990). The most predominant trend is the NW-SE followed by the E-W trend. According to (Naim, et al., 1993), the area is mainly affected by the NW-SE fault trend in the Gulf of Suez represented by the Qattrani fault of normal type, and the Mediterranean E-W trend represented by the Gabal El-Sheeb fault (Fig. 2).

The area under investigation experienced a moderate sized earthquake on August 7, 1847 (F ayoum earthquake) with epicentral intensity MMI = VII (Maamoun et al., 1984). On the basis of instrumental records, this area is characterized by moderate seismicity of M < 6 (Fig. 3A). Earthquakes are distributed in a large area, which extends from Dahshour (on the western side of the River Nile to the Red Sea area and the large-magnitude recurrence is quite big (Maamoun et al., 1984 Abou Elenean, 1997). The earthquake distributions were developed on the basis of records of Helwan observatory (1900

1997) and the recent established Egyptian National Seismological Network (ENSN) from 1997 to 2012.

The fault plane solution of the 1992 earthquake main shock and spatial distribution of its aftershocks imply that this event is characterized by normal faulting with a slight strike-slip component (El-Hadidy, 1993 Hussein et al., 1998). Abou Elenean (1997), using the epicentral distribution, seismicity level, and the similarity of focal mechanisms, considered the area of Dahshour as a seismogenic zone. Tectonically, the faults of this area tend into E-W, parallel to the Mediterranean trend, or N-S parallel to the Gulf of Suez trend. The NW-SE and E-W directions correspond with the surface features, which appeared immediately after the occurrence of 1992 earthquake (Japanese Expert Team, 1993). The majority of earthquakes occurred along the well-defined surface faults with E-W to W-NW orientation as shown in (Fig. 2). The epicenters and focal mechanisms of the earthquake on October 12, 1992 and three other events recently occurred around the area, are shown in (Fig. 3B). Three of these seismic events (June 29, 2000, Local magnitude scale (ML) = 4 July 07, 2005, ML = 4.2 and October 30, 2007, ML = 3.7) occurred at the east of the Dahshour area inside the Suez-Cairo shear zone (Abou Elenean et al., 2009). Focal mechanisms of all these events are normal faults with strike-slip movements.

The earthquake on October 12, 1992 (Body wave magnitude (Mb) =5.8, epicentral intensity MMI = VIII), occurred in Dahshour. It caused tremendous damage performing major disaster in the Nile Delta area. It was noticed in all over Egypt, from Alexandria to Aswan, and even in some parts of surrounding countries (Hussein et. al., 1996 Abd El-Aziz, 2008). The intensity distribution map of this event, according to the Modified Mercalli Intensity scale (MMI), is shown in (Fig. 4) intensity was estimated (MMI = VI-VII) in Cairo, Giza, and Fayoum, where maximum level of damage was reported.

The report of Japanese Expert Team, (1993) estimated that about 8300 dwellings were destroyed, 561 people were killed and 6500 were injured an official investigation revealed (Japanese Expert Team, 1993) that 1343 schools were damaged beyond any repair, 2544 had required major repair and had required repair or maintenance the economic losses caused by this earthquake were estimated at more than US$ 35 million dollars. The earthquake shaking caused liquefaction of the Nile deposits at many sites near the epicenter ( Khater, 1992 Thenhaus et al., 1993). Recent estimations of seismic hazard (Riad et al., 2000 Moharram et al., 2008 El-Hadidy, 2012) show that for 10% probability of exceedence in 50 years (a return period of 475 years), thus the area of study is characterized by moderate level of seismic hazard (PGA=50-100 cm/s2) (Fig. 5).

Generally, the qualitative interpretation for the magnetic maps, aims to get a clear view of the subsurface structures and an estimation of the relative depth of magnetic anomalies sources. It deals with the description of anomalies, especially their symmetry, strike, extension, width, amplitude and gradients (Nettelton, 1976). The aeromagnetic data is provided by the Western Digital Company (1983). These data were corrected prior to our working with them. Different processing methods are applied to the aeromagnetic data. The processing in this study was preliminary carried out by reduction of the magnetic northern pole (RTP), in order to overcome the undesired distortion of the shapes, sizes and locations of the magnetic anomalies an average magnetic inclination of 41[degrees] was used for the area, to eliminate the obliquity of the inclination of the earth's magnetic field. The filters technique (regional, residual and band pass filters) were used in the interpretation and delineation of shallow and deep subsurface structures of the studied area. The quantitative interpretation has been used to determine the depths of shallow subsurface structures (faults and dykes), basaltic intrusions, as well as the basement complex of the considered area the radially averaged power spectrum is the used method for interpretations. The analysis and processing of the aeromagnetic data were done through specialized computer program Geosoft: Oasis Montaj version 6.4.2, (Geosoft, 2007).

The aeromagnetic map of total intensity (Fig. 6) exhibits some positive (red colored) and negative (blue colored) anomalies, and reveals a prominent positive feature, as a circular shape, located at the center of the map area. This anomaly of major positive amplitude is called Agnes (red colored) the north part of the map is occupied by a magnetic belt majorly positive, divided into two positive closures and some positive small noises. The first anomaly tends nearly into the NE-SW with maximum positive amplitude at the northwestern corner the second one is irregularly shaped at the northeastern part, with maximum positive amplitude of Moderate positive anomalies are included between the foregoing positive closures, especially around Agnes anomaly however, the southern part of the map area reveals major negative magnetic belts. The first one is nearly a NE-SW negative magnetic anomaly extending from the southeastern to the southwestern of the map (blue colored) this negative belt exhibits more than six local closures with negative amplitudes and these anomalies also demonstrated condensed noise in their contour lines. The southwestern corner of this belt is occupied by an elongated negative closure with low frequency and low amplitude (blue colored) moreover, the NW-SE moderately positive magnetic belt, lies between the two negative anomalies and the moderately steep magnetic gradient delimits the previous southern negative magnetic belt and the northern positive magnetic belt.

Aeromagnetic data processing Reduction to the magnetic north pole.

A reduction-to-the pole (RTP) transformation is typically applied to the magnetic data of total intensity to minimize the polarity effects (Blakely, 1996). RTP is a filtering technique used to align the peaks and gradients of magnetic anomalies directly over their sources. In this study, the aeromagnetic anomaly data about total intensity reduce the magnetic pole (RTP) (Fig. 7) through Geosoft: Oasis Montaj version 6.4.2 (Geosoft, 2007). This map (Fig. 7) reflects the northward shift in the positions of the inherited magnetic anomalies, due to the elimination of the inclination and their declination of the magnetic field at this area likewise, the sizes of the anomalies become larger and centered to some extent, over their respective causative bodies. In addition, the magnetic gradients became more intensive and steep, as well as the anomalies reliefs increase, giving rise to a higher resolution in the lithologic and structural inferences encountered.

Several zones with high and low magnetic values are present the magnetic highs are separated from magnetic lows by steep gradients. The elongations of magnetic contour lines and their gradients at center of the area indicate that it is structurally-controlled by faults having major axes in NW-SE and E-W directions. The high magnetic anomalies in the northwestern side can be attributed to the occurrence of basic intrusions of the subsurface with high magnetic contents the axes of the fault as well as the directions of magnetic anomalies are trend to the NW-SE and NE-SW in the northwestern, central and the southern parts. A further research of the RTP aeromagnetic map (Fig. 7) includes several local anomalies in the central, southwestern and northeastern parts these anomalies have different reliefs, polarities and shapes. The general magnetic trends of these regions are almost NW-SE, NE-SW and E-W.

Frequency filtering represents a major component of magnetic data processing. As a rule, digital filters are used for signal enhancement that is to remove unwanted noises and enhance desired signals. The nature of "noises" and "signals" varies from case to case. The filtering technique in this study was performed using a cut-off frequency that ranges between 0.08 cycle/ unit data and 2.0 cycle/ unit data. The map after high-pass filtered (Fig. 8) elucidates high-frequency and short-wavelength spot-like magnetic anomalies, which are inferred as residual components. The map (residual) with high-pass component clearly shows several clusters of positive and negative magnetic anomalies, with higher resolution than those on RTP map. The local variations in both frequency and amplitude of these anomalies may be due to the difference in their compositions and/or the relative depths of their sources. The major trends (E-W, NW-SE, N-NW-SSE and NE-SW) are distinguished for the near-surface structures. This indicates that the trend of prominent faults (the trend on the RTP aeromagnetic map) extended in the subsurface up to shallow depths. Moreover, the random orientation of small scale anomalies reflecting that the shallow subsurface has been affected by different stress regimes of the neo-tectonics that may have not affected deep--seated rocks.

The anomaly map with low-pass magnetic filter (Fig. 9) shows a pattern of gradual rotation of magnetic trends from NE-SW and NW-SE towards E-W trend. The low-pass filtered anomalies give view about the subsurface depth, thus the gradual rotation of trends implies that suggested stress regimes (NE-SW and NE-SW) were contained in shallow depths, where the E-W trend dominates only in the deepest part. The deep-seated zone seems to be affected by an E-W stress trend. Also the map (regional) with low-pass magnetic component presents positive and negative magnetic anomalies with deep-seated high amplitude. The deep zone seems to be affected by the E-W stress trend.

The anomaly map with band-pass magnetic filter (Fig. 10) shows that still persist well-defined trends of anomalies on the RTP aeromagnetic map. However, some regional anomalies that do not appear to be related to a subsurface structure, are most probably a result of regional variations in the magnetization or magnetic susceptibility of the rocks at medieval depths. The band magnetic filtered anomaly map shows that the well defined trends of anomalies in the aeromagnetic map still persist.

Analytical 3D signal method

The analytical signal method is a powerful technique to evaluate buried structures which cause significant linear magnetic anomalies, such as fault zones, steps and dykes (Saadi et al., 2008). The map with analytical signal (Fig. 11) was calculated through Geosoft: Oasis Montaj software version 6.4.2 (Geosoft, 2007). This map mostly reveals a number of elongated high anomalies tending to E-W, which is characterized by increasing the small undulations in their contour lines. These anomalies are separated by a lot of local elements of high relief, small area extensions and elongated shapes. This map (Fig.11) could be directly used to obtain the corresponding value of the expected source bodies, in respect to the level of observations and it also displays several circular and linear maxima closures.

Analysis of power spectrum transformation

The method of radial average power spectrum is used to determine the depths of volcanic intrusions, depths of the basement complex and the subsurface geological structures. Several authors, such as Bhattacharya (1965), Spector and Grant (1970), Garcia and Ness (1994), Maurizio et al., (1998), explain the spectral analysis technique based on the analysis of the magnetic data using the Fourier Transform. For this study, the Fast Fourier Transform (FFT) was applied on the aeromagnetic data with RTP, to calculate the energy spectrum. As a result, a two-dimensional power spectrum curve was obtained (Fig. 12) on which two main average levels (interfaces) with depths of 0.5km and 1.8km below the measuring level (for the aeromagnetic map with RTP) were revealed for the deep seated components and also the surface magnetic components respectively. The depth estimations on the aeromagnetic map with RTP indicated that, the depth on the top of the basement complex lies at 1.3 km, while the depth to the basement intrusion is at depth of 2.5 km, below the measuring level.

Structural trends analysis

The Fayoum-Cairo district lies in the south western of Cairo, Egypt which has been affected by several damaging earthquakes and magnetic data have been analyzed to provide new information about the tectonic setting and subsurface structures. Structural trend analysis techniques are frequently used in various fields of geology and geophysics for defining structural problems. In fact the distinctness with which faults appear on the magnetic map depends principally on the existence and the strength of magnetic contrast in the body rocks involved. The aeromagnetic map of anomalies with RTP and the residual anomalies map were interpreted to determine the common structural trends affecting the study area. The azimuth and length of each detected lineament on different maps probably represent the different lengths and directions of faults and/or contacts. These structure systems were statistically analyzed and plotted in the form of Rose diagrams, as shown in (Fig. 13). Examination of these diagrams indicates three predominant structural trends which have varying intensities and lengths. The predominant tectonic trends are the N-W, N-E, and E-W, which produce affectation as deduced from the magnetic point of view, by the other hand, other minor structural trends on the Rose diagrams such as those: N-S, N-NE, and E-NE are less significant in this area.

This study is devoted to the analysis of aeromagnetic data for seismicity interpretation at Dahshour area, Egypt, in order to detect major structural elements on subsurface which affect both, the sedimentary section and the underlying basement complex. Close examination of the different anomalies through the aeromagnetic map with RTP, reveals the dominance of negative magnetic anomalies in southeastern. Also, the differences in magnetic mitigation between each two adjacent magnetic highs and lows, suggest a comparable variation of composition of the subsurface rocks: these anomalies may be attributed to the occurrence of basic intrusions in the subsurface which have high magnetic content at different depths. The analysis of filtered magnetic maps is characterized by the presence of prominent trends in central part, with NW-SE and NE-SW directions these faults may be responsible of the earthquakes occurred. The basement is uplifted in northern and central parts with a depth of 1.3 km, and becoming deeper in southern with a 2.5 km depth. Earthquakes have been occurred in this faulting area with high correlation between seismicity distribution and the inverted tectonic trends: this suggests that the N-NW-S-SE directions on the two nodal planes are fault planes (Fig. 3B). In contrast, the intensity distribution map does not show correlation with the inverted tectonic trends from the aeromagnetic data presented here where the isoseismals elongate into north-south direction. This is mainly due to the surface soil formation as site effect (i. e., the recent alluvium deposits elongate in the north-south trend, covering the Nile River and its Valley). These formation controls much of the intensity distribution map (Fig. 5).

Manuscript received: 30/01/2013

Accepted for publication: 23/05/2014

Abd El-Aziz, K. (2008). Simulating time-histories and pseudo-spectral accelerations from the 1992 Cairo earthquake at the proposed El-Fayoum New City site, Egypt, Acta Geophysica Vol. 56, 4, pp. 1025-1042.

Abou Elenean, K. M. (1997). A study on the seismotectonics of Egypt in relation to the Mediterranean and Red Seas tectonics. PhD Thesis, Faculty of Science, Ain Shams University, Cairo, Egypt. 187 pp.

Abou Elenean, K. M., Mohamed Adel, M. E., Hussein, H. M. (2009). Source parameters and ground motion of the Suez-Cairo shear zone earthquakes, Eastern Desert, Egypt. Natural Hazards Vol. 52, 2, pp. 431-451.

Abu El-Ata, A. S. (1990). The role of seismic-tectonics in establishing the structural foundation and saturation conditions of El-Ginidi basin, western Desert, Egypt. Egyptian Geophysical Society (EGS), Proceedings of the 8th annual meeting pp. 150-189.

Bhattacharyya, B. K. (1965). Two-dimensional harmonic analysis as a tool for magnetic interpretation. Geophysics, vol. 30, pp. 829-857.

Blakely, R. J., (1996). Potential theory in gravity & magnetic applications, Cambridge University Press, Cambridge. 464 pp.

El-Hadidy, S. (1993). Source process of the 1992 Cairo, Egypt earthquake using far field seismogram, Report for the course of seismology 1992-1993, International Institute of Seismology and Earthquake Engineering (IISEE), Japan.

El-Hadidy, M. S. (2012). Seismotectonics and seismic hazard studies in and around Egypt: PhD thesis, Faculty of Science, Ain Shams University, Egypt.

Garcia. J. G., and Ness, G. E. (1994). Inversion of the power spectrum from magnetic anomalies. Geophysics, vol. 59, 3, pp. 391-401.

Geosoft: Oasis Montaj Program. (2007). Geosoft Mapping and Application System, Inc, Suit 500, Richmond St. West Toronto, ON Canadab N5SIV6.

Ghazala, H., (2001). Tectonic setting of the area between Cairo and Fayoum provinces, Western Desert, Egypt: Implications of gravity models. Proceedings of the 2nd International Symposium of Geophysics, Tanta University, Egypt, pp. 101-110.

Hassoup A., Alrifi N., Mekkawi M. and Othman K. (2009). Subsurface structure and seismicity characteristics of south Sinai area, Egypt. International Journal of Exploration Geophysics, Remote Sensing and Environment (EGRSE), Vol. XVI, pp. 9-19.

Hussein, H. M,, Korrat, I. M., Abdel Fattah, A. K. (1996). The October 12, 1992 Cairo earthquake a complex multiple shock, Bulletin Of The International Institute Of Seismicity And Earthquake Engineering (IISEE) Japan vol. 30, pp. 9-21.

Hussein, H. M., Abou El-Enean, K. M., Ibrahim, E. M., , Abu El-Ata, A. S., Duda, S. J. (1998). Spectral magnitudes and source parameters for recent damaging earthquakes in Egypt, Bulletin Of The International Institute Of Seismicity And Earthquake Engineering (IISEE), Japan vol. 34, pp. 1-24.

Japanese Expert Team (1993). Report of Japan Disaster Relief Team on the earthquake in Arab Republic of Egypt of October 12, 1992, Japan International Corporation Agency. 89 pp.

Khater, M. (1992). Reconnaissance report on the Cairo, Egypt Earthquake of October 12 1992. Technical Report NCEER-92-0033, SUNYBuffalo, Buffalo, NY 52 pp.

Maamoun, M., Meghaed, A., Allam, A. (1984). Seismicity of Egypt. Bulletin of Helwan Institute of Astronomy and Geophysics. Vol. 4, pp. 109-160.

Maurizio, F., Tatina., Q., Angelo., S. (1998). Exploration of a lignite bearing in Northern Ireland, using ground magnetic. Geophysics, vol. 62, 4, pp. 1143- 1150.

Meshref, W. M. (1990). Tectonic Framework in the Geology of Egypt. Edited by Said, R., A. A. Balkema, Rotterdam, pp. 113-155.

Moharram, A. M., Elghazouli, A. Y, Bommer, J. J. (2008). A framework for a seismic risk model for Greater Cairo. Soil Dynamics and Earthquake Engineering 28, pp. 795-811.

Moustafa, S. S. R. and Takenaka, H. (2009). Stochastic Ground Motion Simulation of the 12 October 1992 Dahshour Earthquake, Acta Geophysica, Vol. 57, 3, pp. 636-656.

Naim, G. M., Hayah al-Misriyah al-Ammah lil-Misahah al-Jiyulujiyah wa-al-Mashruat al-Tadiniyah. (1993). A preliminary report on the Dahshour earthquake, 12 October 1992. Egyptian Geological Survey and Mining Authority. Cairo, Egypt, 48 pp.

Nettelton, L. (1976). Gravity and magnetics in oil prospecting. McGraw Hill Book Company, New York. 464 pp.

Riad, S., Ghalib, M., El-Difrawy, M. A., Gamal, M., (2000). Probabilistic seismic hazard assessment in Egypt. Annals of the Geological Survey of Egypt 2000 Vol 18, part 3, pp. 851-881.

Said, R. (1990). The Geology of Egypt. Rotterdam Brookfield: A. A. Balkema Press, The Netherlands. 734 pp.

Spector, A., Grant, F. S.( 1970):Statistical models for interpreting aeromagnetic data.

Thenhaus, P. C., Sharp, R. V, Celebi, M., Ibrahim, A. B. K., Van de Pol, H. (1993). Reconnaissance report on the 12 October 1992 Dahshour, Egypt, Earthquake. United States Geological Service (USGS) Survey Open File Report, pp. 93-181.

Ahmed Khalil (1,2), Mostafa Toni (3), Awad Hassoup (1) and Khamis Mansour (1,2)

(1) National Research Institute of Astronomy and Geophysics, Helwan, Egypt (2) Laboratory of Exploration Geophysics, Earth Resource Engineering Department, Faculty of Engineering, Kyushu University, Fukuoka, Japan (3) Geology Dept., Faculty of Science, Helwan University, Cairo, Egypt


Integration of airborne geophysical and ASTER remotely sensed data for delineation and mapping the potential mineralization zones in Hamash area, South Eastern Desert, Egypt

The advancement of geophysical methods and remote-sensing techniques, with improved processing models in recent years, encourage for further applied research in gold exploration and other associated elements and becoming useful tools for the exploration of new occurrences. The main objective of this research paper is to explore and map the hydrothermal alteration zones associated with gold mineralization in the Hamash area based on airborne geophysical (aeromagnetic and airborne gamma-ray spectrometry) and ASTER remote sensing data. For this purpose, ASTER and geophysical data are processed by different techniques including band ratios, minimum noise fraction, Crosta techniques, constrained energy minimization and F-parameter maps which allow for discriminating different rock units and delineating hydrothermal alteration zones. Furthermore, structural lineaments of surface and shallow-seated are effectively extracted and auto-mapped using ASTER and magnetic data. The potential mineral favourability map consists of F-parameter, interpreted structural lineaments, MNF, band ratio (4/8, 4/2, and 8/9), Crosta technique and CEM maps are combined through GIS model, by the application of fuzzy overlay analysis. This enabled to locate and map the areas of maximum potentiality of mineral favourability sites that occur in central and north-eastern parts within the Hamash area.

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ACKNOWLEDGMENTS

We would like to thank Gold Fields Ltd. for access to data for the purpose of this study. S. Kuhn is supported by an Australian Postgraduate Award Scholarship from the University of Tasmania. This research was conducted in collaboration with the ARC Industrial Transformation Research Hub for Transforming the Mining Value Chain (project number IH130200004) at the Centre of Excellence in Ore Deposits, University of Tasmania. The views expressed herein are those of the authors and are not necessarily those of the Australian Research Council. We used the Orange software package (Demsar et al., 2013) for RF classification. Preprocessing, interpolation, and plotting were performed using Geosoft Oasis Montaj and ESRI ArcGIS. D. Doutch is thanked for his input on the geologic and structural setting of the project. We thank the assistant editor, associate editor, and three reviewers for their suggestions, which have significantly improved the manuscript.


Geosoft Oasis Montaj Local Datum Transform - What is the purpose of this parameter? - Geographic Information Systems

Airborne geophysical survey: Bakersfield 1° x 2° Quadrangle tabular digital data https://mrdata.usgs.gov/magnetic/show-survey.php?id=Bakersfield U.S. Geological Survey, Department of the Interior, the National Geophysical Data Center, U.S. Department of Energy

Aeromagnetic and aeroradiometric data for the Conterminous United States and Alaska from the National Uranium Resource Evaluation (NURE) Program of U.S. Department of Energy U.S. Geological Survey Open-File Report OFR 2009-1129

Aeromagnetic surveys are used for geophysical prospecting. Some variations in magnetic measurements are caused by rocks that contain significant amounts of magnetic minerals (magnetite being the most common). These anomalies reflect variations in the amount and type of magnetic material and the shape and depth of the body of rock. Aeromagnetic anomaly maps are important tools in mapping surficial and buried igneous rocks. The features and patterns of aeromagnetic anomalies can also be used to delineate details of subsurface geology including the locations of buried faults and the thickness of surficial sedimentary rocks. Aeroradiometric surveys measure the radiation emanating from the earth's surface, which provides general estimates of the geographic distribution of uranium, thorium, and potassium in surficial and some bedrock units. Bismuth 214 and Thallium 208 are decay products of Uranium and Thorium. Along with Potassium 40 they give identifiable peaks in the gamma-ray spectra of naturally occurring radiation. The element data and the ratios of the element data are used to help map surficial geology and to detect concentrations of radioactive minerals.

The U.S. Department of Energy through Bendix Corp. contracted numerous airborne surveys over a period from 1974 to 1981 covering most of the conterminous United States and much of Alaska. The primary purpose was to obtain airborne radiometric data in order to locate and evaluate uranium resources. Aeromagnetic data were also acquired at the same time. In the mid-1980's, all the NURE Program's data were given to the U.S. Geological Survey. The aeromagnetic data were also archived at the National Geophysical Data Center. With the improvement in digital communication and the ability to store and transmit large data sets, the USGS is now able to release the flight-line data in a common format. The U.S. Geological Survey has contracted or flown numerous airborne surveys over a long period (1950's to present). Much of the digital flight-line data have been released to the public through a companion DVD and a web site. Reference is in the Cross-Reference section of this metadata file. A companion CD-ROM/web site has been released containing magnetic data that were generated by digitizing analog maps. The original analog flight-line profiles used to create the analog maps are unavailable. Reference is in the Cross-Reference section of this metadata file. CD's have been released containing the original radiometric flight-line data in various formats. Reference is in the Cross-Reference section of this metadata file. 19791030 19791110 Time period indicates dates of airborne survey data collection. Time period is expressed in the format YYYYMM or YYYYMMDD when further accuracy is available.

none planned -120.00 -118.00 36.00 35.00 -120.00 35.00, -120.00 36.00, -118.00 36.00, -118.00 35.00, -120.00 35.00 nonegeophysical surveysaeromagnetic dataairborne surveysmagnetic surveysresidual magnetic fieldtotal fieldmagneticaeroradiometric surveysradiometric surveysradiometricradioactivityuraniumthoriumpotassiumtotal countUSGS Thesaurusgeophysicsgeospatial datasetsmagnetic field (earth)aeromagnetic surveyingfield monitoring stationsaeroradiometric surveyingradioactivityuraniumthoriumpotassium

http://mrdata.usgs.gov/geophysics/surveys/NURE/bakersfield/bakersfield.jpg
Reduced-size image depicting the data, 971 x 695 pixels, 312,543 bytes
JPEG These USGS employees contributed to reformatting and archiving these data: Pat Hill, Bob Kucks, Rick Saltus, Ron Sweeney, Sarah Shearer Cooperating contributors from the National Geophysical Data Center are: Ronald Buhmann, David Dater, Susan McLean, Stewart Racey The Comphrensive Model data were supplied by: Prof. Dhananjay Ravat, University of Kentucky These data were originally recorded on 9-track magnetic tapes and were transferred to CD-ROM. Data processing took place on a Dell personal computer running a Windows XP operating system. Data were reformatted using the Geosoft, Inc., program Oasis Montaj version 6.3. U.S. Geological Survey

Digitized Aeromagnetic Datasets of the Conterminous United States, Hawaii, and Puerto Rico raster digital data U.S. Geological Survey Open-File Report OFR 99-557

CD-ROM or online files Complements this publication with analog data <URL:http://pubs.usgs.gov/of/1999/ofr-99-0557/html/mag_home.htm U.S. Geological Survey

Digital Aeromagnetic Datasets of the Conterminous United States and Hawaii raster digital data U.S. Geological Survey Open-File Report OFR 02-361

CD-ROM or online files Complements this publication with digital data <URL:http://pubs.usgs.gov/of/2002/ofr-02-361/mag_home.htm U.S. Geological Survey

Aerial Gamma-Ray Surveys of the Conterminous United States and Alaska raster digital data U.S. Geological Survey Open-File Report OFR 99-0562-A through -M

Thirteen CD-ROMs U.S. Department of Energy (DOE) Grand Junction Office

Airborne gamma-ray spectrometer and magnetometer survey, Mariposa Quadrangle (California, Nevada), Fresno Quadrangle (California), and Bakersfield Quadrangle (California) map Grand Junction Bendix Office Report (GJBX) GJBX-231(80)

DOE Grand Junction Office

map scale 1:500,000 Author(s): High Life Helicopters, Inc. and QEB, Inc. U.S. Department of Energy (DOE) Grand Junction Office

Bakersfield Quadrangle, residual intensity magnetic anomaly profile and contour maps map Grand Junction Map Open-file Report GJM-473

DOE Grand Junction Office

Flight Path Recovery The horizontal position of the survey aircraft used to collect data was determined by reconciling down-looking photographs (recorded on continuous-strip film) with topographic maps and orthophotoquadrangle maps. Fiducial numbers and marks, impressed on any paper strips that were recording data or added to magnetic tape records, were included as a function of time to further reconcile location with instrumentation. The aircraft vertical position was determined using the navigational positioning equipment on the aircraft, which were radar altimeter and barometric altimeter. Barometric altimeter data are not available for most of these data sets. Radar altimeters are estimated to have an error of 2-5% of the altitude (Richard Hansen, PRJ, Inc., written communication). The magnetometer was carried in a bird towed on a line that was an unknown length below the aircraft. The bird as it is towed is slightly behind the aircraft and therefore the vertical distance between the magnetometer and the aircraft is less than the length of the line but remains constant for the survey.

Conversion of measured values to geographic position and magnetic and radiometric values was performed by the contractor using industry standard practices. Details are found under Attribute Accuracy Report, Horizontal_Position_Accuracy_Report, and Vertical_Position_Accuracy_Report Conversion processes, if reported, may be found in the U.S. Department of Energy's published GJO- or GJBX- reports for the quadrangle or group of quadrangles. Unpublished products generated by the contractor included magnetic tapes and perhaps some written documentation.

USGS reformatting of contractor data to standard format. USGS personnel used the software package Oasis Montaj version 6.3 by Geosoft, Inc., to read in the original contractor's data. Positioning and magnetic values were checked for obvious errors or spikes. Values of -9999.9,-999.9, -99.9, etc., were given where the value could not be reasonably corrected or, in some cases, the whole record was removed. Information that was missing from the data file but recorded elsewhere, such as year flown, was added th the file. The radiometric data were not checked for errors except for dummy values which were replaced with -99.9, -999.9, etc. The reformatted data files were written in the format described in the section on Entity_and_Attribute_Overview.

303-236-5486 USGS Open-File Report OFR 2009-1129 Although all data published on this web site have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. ASCII Magnetic data file Each line contains data in the following format, beginning with line 1 (no header included): line I6 fid I8 time I8 day I5 year I6 latitude F10.4 longitude F11.4 radalt F7.1 totmag F9.1 resmag F9.1 diurnal F9.1 geology A10 resmagCM4 F9.1 Radiometric data file Each line contains data in the following format, beginning with line 1 (no header included): line I6 fid I8 time I8 day I5 year I6 latitude F10.4 longitude F11.4 radalt F7.1 resmag F9.1 geology A10 qual A8 app_K40 F9.1 app_U_BI214 F9.1 app_Th_TL208 F9.1 U_Th_ratio F7.1 U_K_ratio F7.1 Th_K_ratio F7.1 total_count F10.1 atmos_BI214 F7.1 air_temp F8.1 air_press F8.1 gunzip 2.1 http://pubs.usgs.gov/of/2009/1129 none Peter N Schweitzer USGS Eastern Mineral and Environmental Resources Science Center Geologist mailing address 12201 Sunrise Valley Drive Reston VA

USA 703-648-6533 703-648-6252 [email protected] bakersfield_meta.txt This dataset was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. CSV Flight-line airborne magnetic anomaly measurements gzip -d 2.6025724411011 http://mrdata.usgs.gov/geophysics/surveys/NURE/bakersfield/bakersfield_mag.xyz.gz CSV Flight-line airborne radiometric measurements gzip -d 4.0185747146606 http://mrdata.usgs.gov/geophysics/surveys/NURE/bakersfield/bakersfield_rad.xyz.gz none 20141204 USGS Gravity and Magnetics contact mailing address U.S. Geological Survey Box 25046 Mail Stop 964 Denver Federal Center Denver CO

303-236-5652 Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998


Ranking potentially favorable mineralization zones using fuzzy VIKOR vs. Dempster-Shafer-fuzzy AHP methods, a case study: southeast of the Sarcheshmeh copper mine, Kerman, Iran

In this study, a different ranking method has been proposed to prioritize the mineral potential areas and select the best potential area to decrease potential risks of mineral exploration. In this regard, at first, the area located in the east-southeast of the Sarcheshmeh copper mine was selected as mineral targets due to their high potential of porphyry copper occurrences. Then, the favorable porphyry copper areas were determined through collecting and integrating multiple exploratory evidential layers derived from remotely sensed imagery, geochemical, geophysical, lithological, and structural maps and images using the fuzzy logic approach in the GIS environment. Next, through building the decision matrix, the fuzzy VIKOR and Dempster-Shafer-fuzzy AHP methods were applied to estimate the favorability for copper porphyry deposits from information data layers, and the selected prospects were ranked and prioritized based on their scores obtained by each method. A comparison of the results obtained from each method with the previously discovered porphyry copper deposits and indications in the study area revealed a great match between the predicted and known deposits. The validation of results proved the ability of the proposed approach in detecting the highly favorable areas, particularly in the areas embedding known porphyry copper mineralizations. Finally, by applying the fuzzy VIKOR method to the potential areas located in the study area, the Darreh-Zar porphyry mine, as well as a region in the southeast of the Saecheshmeh mine, and a region in the south of Kouhpanj with the minimum values of Q parameter in fuzzy VOKOR method, i.e., 0.021, 0.046, and 0.166, were chosen as the best areas. The results of ranking through the Dempster-Shafer-fuzzy AHP method showed that a region in the southeast of the Sarcheshmeh mine with a priority value of 0.742, a region in the south of Kouhpanj with a priority value of 0.727, and the Dareh zar porphyry mine with a priority value of 0.653, are the best potential areas. The results of the fuzzy VIKOR and Dempster-Shafer-fuzzy AHP methods for ranking the potential areas are consistent with each other, which are validated by previously known areas as well.

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Resumo

Regiões produtivas no Sistema Aquífero Embasamento Cristalino (SAEC), estado do Paraná, Brasil, foram identificadas qualitativa e quantitativamente através da correlação espacial de poços e condicionantes geológicos, tais como lineamentos, hidrografia, aeromagnetometria e litologia. Diferentes métodos aplicados em aquíferos associados a rochas ígneas e metamórficas pré-cambrianas pelo mundo, e alguns estados brasileiros, foram integrados e aplicados no SAEC, com objetivo de compreender a melhor escala para análise da produtividade. A mediana de produtividade de 224 poços analisados é 0.29 m 3 /h/m. Sob uma avaliação regional multiescala, os resultados mostraram que a melhor condição está associada com a distância de 350 m dos lineamentos (1:100,000), especialmente aqueles com direções N40W, N10E e N70E. Considerando as unidades hidrolitológica, gnaisses são os mais produtivos, especialmente quando os lineamentos coincidem com estruturas regionais, tais como zonas de cisalhamentos, foliações e reativações tectônicas cenozoicas. Quartzitos, granitoides, xistos, filitos e riolitos também foram favoráveis quando próximos a importantes rios e não necessariamente coincidentes com lineamentos regionais, alta densidade de lineamentos ou com fraturas verticais. As áreas de intersecção dos lineamentos e o manto de intemperismo não serviram como um parâmetro discriminatório. À medida que as profundidades medianas dos poços alcançam 90 metros, a extração de gradientes magnéticos orientados refere-se a fontes magnéticas de até 800 m de profundidade, corroborando, portanto, com lineamentos mapeados em superfície, e estruturas não aflorantes. Considerando a complexidade do meio e o uso global das águas subterrâneas de aquíferos fraturados, este trabalho contribuiu discriminando parâmetros geoespaciais para diminuir o risco exploratório no SAEC.


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