2001

Exploration Chapter 1: About This Volume

Chapter 1

About This Volume

In This Chapter

• Purpose• Organization of this Volume• General Information

Purpose

This volume of the Gemcom for Windows user manual provides youwith the following:

• An overview of the Gemcom for Windows exploration anddatabase management functions.

• Procedures and basic concepts for using exploration anddatabase management functions.

Organization of This Volume

Volume II: Exploration is divided into five sections: Introduction,Workspaces, Drillholes, Polygons, and Plane Plots.

Section I: Introduction

Chapter 1: About this Volume describes this volume.

002

Section I: Introduction Gemcom for Windows

Chapter 2: Introduction to the Exploration Modules outlines theexploration and database management functions of the Gemcom forWindows system, describes some of the basic concepts involved, andillustrates the standard functions provided by the system.

Section II: Workspaces

Chapter 3: The Gemcom for Windows Workspace describesthe organization of the project, its associated database, workspacesand files, and outlines some general database managementfunctions.

Chapter 4: Creating and Modifying Workspace Structuresdiscusses minimum workspace structures for the various types ofworkspaces and outlines the procedures involved in creating a newworkspace and modifying the structures of new or existing workspaces.

Chapter 5: Importing and Merging Data outlines theprocedures for converting existing PC-XPLOR databases, and foradding data to workspaces by importing or merging existing datafrom ASCII files or from files created by other applications.

Chapter 6: Editing Data describes how the Workspace Editor canbe used to view, add and edit data in an existing workspace.

Chapter 7: Extracting Data describes the Gemcom for Windowsextraction file, its uses, and the procedure for creating it.

Chapter 8: Validating Data discusses the reasons for validatingdata and outlines the procedures for performing the two types ofdata validation processes available in Gemcom for Windows.

Chapter 9: Filters and Key Indices describes the uses of filtersand key indices in defining subsets of data from a workspace andoutlines procedures for their creation.

Chapter 10: Reports discusses the various types of reports thatcan be generated using Gemcom for Windows, describes how tocreate or modify a report formatting macro using the reporting

Exploration Chapter 1: About This Volume

language (the syntax and set of commands you can use to formatworkspace reports), and outlines the procedures involved in reportcreation.

Chapter 11: Data Manipulation describes the various optionsavailable for manipulating workspace data by calculating new datavalues from existing data values.

Chapter 12: Statistical Analysis describes how to preparestatistical analyses, frequency distribution analyses, andmultivariate analyses of data within a workspace, and then use theinformation to create a variety of graphs in QuickGraf.

Chapter 13: Semi-Variogram Analysis discusses two types ofsemi-variograms and explains how to create experimental semi-variograms from data in the workspace.

Chapter 14: QuickGraf describes the QuickGraf utility and itsfunctions and discusses the use of linear and semi-variogram models.

Section III: Drillholes

Chapter 15: Working with Drillholes outlines functionsavailable on the Drillhole menu in Gemcom for Windows.

Chapter 16: Drillhole Compositing discusses the methodsavailable for drillhole compositing, including compositing fromexisting workspace data only, and compositing from theintersections of drillholes and surfaces or solids.

Section IV: Polygons

Chapter 17: Polygons and Outlines discusses how polygon andworking outlines are used and defined and describes methods ofloading and saving polygons.

Chapter 18: Working with Polygons describes various methodsfor creating, modifying and identifying polygons, intersecting and


merging existing polygons to create new polygons, and viewingpolygons and associated attributes and calculations.

Section V: Plane Plots

Chapter 19: Creating Plane Plots briefly describes the types ofplane plot GGP files that can be created using Gemcom forWindows and outlines the procedures for selecting planes for GGPplots, creating surface topography/vertical section intersectionplots, and viewing and printing the prepared plot files.

Chapter 20: Symbol Plane Plots explains how to make surfacemaps, plan views and sections that show symbols and text at thelocations of points defined in the active workspace.

Chapter 21: Drillhole Plane Plots describes how to make surfacemaps, plan views and sections displaying drillhole traces that areannotated with data from the workspace.

Chapter 22: Polygon Plane Plots outlines the procedures forplotting digizited polygons on surface maps, plan views or sections.

Chapter 23: Structure Maps describes how to make surface mapsand plan views that display special symbols describing thegeological structures at points defined in the workspace.

Chapter 24: Gridding and Contouring discusses how to use datainterpolation methods to create a regular grid over the area covered bythe workspace, and then produce a contour map from that grid.

General Information

For overall information about the Gemcom for Windows UserManual, including organization, conventions, technical suportcontacts, and master index, see the Manual Guide & Master Indexbooklet.

Exploration Chapter 2: Introduction to Exploration

Chapter 2

Introduction to Exploration

In this Chapter

• Introduction• The Exploration Functions

Introduction

The Exploration functions in Gemcom for Windows provide theuser with integrated tools for data management and data andgraphical analysis of exploration and other spatial data within aspecific project. Gemcom for Windows uses the Microsoft Access-compatible “Jet” OLE industry-standard database engine to manageproject databases. The Jet engine is fast and reliable, and allowsyou to access your Gemcom for Windows database from othercompatible database management applications.

Gemcom for Windows is designed to store, manage, report, display,and analyze, both statistically and geostatistically, any type ofspatial data combined with any qualitative or quantitative data.Spatial data is categorized into four generic data types:

• Point data. Individual samples at unique locations: geologicaldata, structural data, geochemical analyses, assay data andenvironmental data.

• Traverse data. Individual samples at points or intervalsgrouped along straight lines: trenches, surface cut lines,underground adits, straight or vertical drillholes.


• Drillhole data. Individual samples at points or intervalsgrouped along deviating lines: drillholes, undergroundhaulages.

• Polygon data. Individual samples interpolated as orrepresented within polygons with known coordinates: claimboundaries, orebodies.

These data types are stored in user-defined structures within thedatabase called workspaces. The Gemcom for Windows workspacestructure is very flexible, however, and workspaces are notrestricted to the above types of data. A fifth category of data, OtherData, is included for this possibility, allowing you to define aunique workspace structure to fit your data.

Database Management

Gemcom for Windows allows you to store a wide range of data bycreating a virtually unlimited number of workspaces within oneproject database, and provides you with a number of tools andfeatures for managing the data within these workspaces:

• Flexible structure definition, including an easy-to-use Wizardfor creating new workspaces;

• Variety of data types;

• Onscreen data entry and editing;

• Import facilities for loading data from text files and otherapplications;

• Comprehensive indexing;

• Filtering and sorting;

• Customizable reporting;

• Data extraction and export;


• Data manipulation through user-defined expressions.

Data Analysis

Gemcom for Windows can perform detailed statistical andgeostatistical analyses on any aspect of the data in the workspaces.You can prepare the following:

• Classical statistics;

• Frequency distribution analyses;

• Multivariate statistics;

• Linear and 3D semi-variogram analyses.

You can also produce detailed graphical output using thecomprehensive graph plotting and modelling tools in the QuickGrafutility.

Drillhole Operations

The Gemcom for Windows Drillhole menu commands allow you towork with drillhole survey and assay data by performing thefollowing functions:

• Loading drillholes into the graphical work area for viewing.

• Selecting drillhole intersects.

• Customizing the display of your drillholes onscreen.

The Drillhole menu also allows you to perform two types of drillholeor traverse compositing:

• Compositing based on existing workspace data.

• Compositing based on the intersections of drillholes or traversedata with surfaces or solids.


Polygon Operations

The Gemcom for Windows Polygon menu allows you to representyour data using a number of polygon functions:

• Creating polygons either manually or using one of threeautomatic processes to represent various aspects of your data.

• Loading, unloading and saving polygons;

• Calculate volumes and tonnages of material types asrepresented by individual polygons.

Plane Plot Graphics Files

You can produce sophisticated graphical output for multiple planessimply and efficiently with the Gemcom for Windows Explorationmodule. The system has the following extensive integrated graphicscapabilities:

• Displaying plan view and section data.

• Preparing geological maps, X-Y plots, symbol plots, drillholeplots, polygon plots and contour plots.

• Projecting all graphical output onto surface maps, horizontalplan views, vertical and inclined sections.

The Exploration Functions

The exploration functions provided by Gemcom for Windows arefound in four menus. Each of these menus contains a number ofsubmenus and commands for performing related functions. Thissection describes all available functionality. Note that dependingon your specific license files, certain commands may not beavailable in your Gemcom for Windows setup. If you have


questions about your setup, please refer to your license agreementor call Gemcom.

• The Workspace menu. Use this menu to create workspaces,select an active workspace, enter and edit data, validate data,filter, index and sort data, create reports, and extract andmanipulate data. You can also use the Analysis submenu toperform various types of statistical and geostatistical analysesof your data.

• The Drillhole menu. This menu allows you to load, select, anddisplay, specific drillhole data, and composite drillhole lengthsusing two different methods.

• The Polygon menu. This menu allows you to create, load,display, and manipulate data represented as polygons.

• The Tools menu. The Create Plane Plots submenu on theTools menu is also part of the Exploration module. Use thecommands on this submenu for preparing various types of planeplots for surface maps or specified planes.

The Workspace Menu

The Workspace menu provides facilities that enable you to do thefollowing:

• Select an active workspace. You can select the workspacefrom your project which contains the data you wish to workwith. Gemcom for Windows will store the active workspacewithin the GEM4WIN.GES session file, so that the selectedworkspace will remain active between Gemcom for Windowssessions, until you select a new active workspace. Theworkspace selected by this command is used by most Gemcomfor Windows exploration operations; however, in a number ofareas of the program, you must select a workspace within therelated menu (for example, in order to use most of thecommands on the Polygon menu, you must select a polygon


workspaces using a command on that menu). See Chapter 3:The Gemcom for Windows Workspace.

• Create or modify a workspace. Within the Structure Editor,you can use the Structure Editor design view or a WorkspaceWizard to define workspace type and attributes and the numberof tables within the workspace. You can also add or delete tablesin an existing workspace, or fields in a new or existing table.Field data types and attributes can also be modified. Existingworkspaces are automatically reconstructed with the newstructure. See Chapter 4: Creating and Modifying WorkspaceStructures.

• Delete a workspace. You can delete an existing workspace(including all data contained within that workspace). SeeChapter 4: Creating and Modifying Workspace Structures.

• Import and merge data from text files. You can import datadirectly from text files that are either in column aligned format(flat file) or delimited format. File formats can be defined andthen stored in profiles for multiple use. Importing files appendsdata into new records in the database. Merging matches datavalues to existing records in the database based on the contentsof selected key fields. See Chapter 5: Importing and MergingData.

• Advanced import and merge. This module allows you toimport data from other commonly used geological softwarepackages. Currently supported systems include GeostatSystems International, Log II and GEOLOG. See Chapter 5:Importing and Merging Data.

• Enter and edit data. Using the Workspace Editor, you canview, enter or edit data in the active workspace. This editorfeatures a number of tools such as cut and paste, block deletion,searches, split screen editing, field binding and auto-incrementof values between records. See Chapter 6: Editing Data.


• Extract data. You can create an extraction file containing asubset of data from the active workspace according to variousselection criteria. See Chapter 7: Extracting Data.

• Validate workspace data. You can verify the validity of thedata in the active workspace by checking for overlapping ormissing intervals or duplicate records using the commands onthis submenu. See Chapter 8: Validating data.

• Filter and index data. You can create an external index ofdata subsets in the active workspace by defining filters and keyindices. A filter is a list of selection criteria that can be appliedto the workspace while running most Gemcom for Windowsapplications. A key index to the workspace can be created usingfilters, other key indices, and manual record selection, andsorted based on the contents of selected fields in the workspace.See Chapter 9: Filters and Key Indices.

• Make reports. You can make quick or detailed reports of datain the active workspace. The quick reporting facility allows youto create simple reports with the help of workspace field lists.The Gemcom for Windows report-writing macro language willlet you make more complex and custom formatted reports.Reports can be directed to the screen, to the printer or to textfiles. See Chapter 10: Reports.

• Manipulate data. A complete set of data manipulation toolsallows you to perform various transformations of data in theactive workspace. You can define simple or conditionalexpressions for fields in any table; transfer data between tables,interpolate missing data values using existing values, format orconcatenate string fields, transform coordinates from onecoordinate system to another; desurvey downhole data intocoordinate data; and format drillhole data from other systemsso that it is compatible with Gemcom for Windows. SeeChapter 11: Data Manipulation.

• Perform statistics and frequency distribution analysis. Youcan calculate a variety of statistical indicators, such as means,standard deviations and variances, on subsets of data extracted


from the databases and stored in the standard extraction fileformat. In addition, you can perform complete normal and log-normal frequency distribution analysis on the data sets. This letsyou produce histograms and frequency distribution curves from thedata. This module interfaces directly with the QuickGraf utility forplotting graphs. See Chapter 12: Statistical Analysis andChapter 14: QuickGraf.

• Perform multivariate statistical analysis. You can createcorrelation matrices for selected variables from the activeworkspace. The module interfaces directly with QuickGraf tocreate scattergrams displaying the relationship between twovariables. The modelling command in QuickGraf also allows youto perform simple regression analysis on these data sets. SeeChapter 12: Statistical Analysis and Chapter 14: QuickGraf.

• Perform drillhole semi-variogram analysis. You can createexperimental semi-variograms directly from drillhole ortraverse workspace data. The calculation process allows you toapply a variety of selection criteria to the workspaces foranalyzing subsets of data. The module automatically calculatesstandard semi-variograms as well as a variety of normalizedsemi-variograms, and interfaces directly with QuickGraf to plotthese experimental curves. An interactive modelling commandin QuickGraf allows you to fit model semi-variograms to theexperimental curves. See Chapter 13: Semi-Variogram Analysisand Chapter 14: QuickGraf.

• Perform three-dimensional semi-variogram analysis. Youcan create experimental semi-variograms from data in a standardextraction file. You can calculate the semi-variograms in up totwelve three-dimensional directions at any one time. The moduleautomatically calculates standard semi-variograms as well as avariety of normalized semi-variograms and interfaces directly withQuickGraf to plot these experimental curves. An interactivemodelling command in QuickGraf allows you to fit model semi-variograms to the experimental curves. See Chapter 13: Semi-Variogram Analysis and Chapter 14: QuickGraf.


• Graph statistical and semi-variogram analyses. This is aninteractive graphing module that interfaces directly with all theanalysis functions. It provides you with a flexible tool forquickly producing and plotting graphs with a variety of scaling(such as normal, logarithmic or probability), annotation andgridding options. The module also features a number ofmodelling commands. QuickGraf uses standard Windowsprinter drivers to allow you to print or plot out hard copies ofyour graphs on any Windows-compatible printer or plotter. SeeChapter 14: QuickGraf.

The Drillhole Menu

The data collected from drillholes and associated assays is vital tothe exploration process. Gemcom for Windows allows you to loadcomplete drillhole workspaces or subsets of drillhole workspacesthat are stored in your Gemcom for Windows projects. Once thesedrillholes are loaded, you can display them in a variety of ways tofacilitate analysis of the data. You can also use them to help youdefine lithological boundaries or as data points for modellingsurfaces.

The Drillhole menu provides you with facilities to do the following:

• Load drillhole data. You can load or unload drillhole datafrom one or more active drillhole workspaces.

• Select drillhole intersects. You can select or deselect alldrillhole intersects, or specify which drillhole intersects toselect either individually (manually), by specifying a field value,or by using a clipbox. You can also create an extraction file ofthe data values for the selected drillhole intersects.

• Determine drillhole display. You can customize five mainelements of the drillhole display: the drillhole name, collarsymbol, trace symbols, trace line, and trace annotations. Allelements are optional and can be displayed in any combination.Other display settings include show/hide toggles and distancemarkings. You can also query drillhole data interactively by


picking points along the trace with the mouse to displaydetailed downhole information.

The Drillhole menu also provides you with drillhole compositingfunctions. You can calculate composited values from drillhole ortraverse type workspace data, or from the intersections of drillholeswith surfaces or solids. Composites are weighted averagecombinations of interval data. Gemcom for Windows uses a two-stage compositing method. The first stage determines the length ofthe composite interval using a variety of techniques such as fixedlengths, intervals from another table, fixed lengths within intervalsfrom another table, intersections with planes, and cut-off value.The second stage calculates the weighted average composite valuesusing data sources from single or multiple tables.

You can also use the commands in this submenu to perform thefollowing functions:

• Calculate thickness. You can calculate true, horizontal, andvertical thickness for selected intervals along drillholes ortraverses based on specified strike and dip angles.

• Assign grades to solids from drillholes. You can assign oneor more grades to active geology class solids based on lengthweighted intervals of all drillholes that pass through each solid.These grade values can be used as an alternative to blockmodels when solid grades are required for reserves reporting.

• Create ASCII files of drillhole/solid intersections. You canintersect all drillholes loaded in memory with all active solidsand save the results to a user-specified ASCII file.

See Chapter 15: Working with Drillholes and Chapter 16: DrillholeCompositing.

The Polygon Menu

The functionality in the Polygon menu is based on the practice ofrepresenting geological information such as lithological or ore zones


on planes as points and line segments which are assembled intopolygons. Each polygon is then identified with a user-defined set ofspecific qualities and characteristics. The Polygon menu providesfacilities that allow you to perform the following functions:

• Create and identify polygons. Polygons can be created bymanually digitizing points and line segments. You can alsocreate polygons automatically from existing data such as pointdata, other polygons, and solids. Closed polygons can beassigned a variety of different attributes depending on how youintend to use them.

• Import and export polygon data. You can import polygonsfrom GeoModel and from the Ore-Control component ofGemcom for DOS. You can also import status lines (polylines) aspolygons. The Export function allows you to export Gemcom forWindows polygon data to Gemcom for DOS, as a status line ASCII

file, or as a clipping polygon.

• Define polygon and working outlines. These outlinesdetermine how polygons will be displayed, which fields from thepolygon workspace will be associated with them as attributes,and how polygons associated with different polgyon outlineswill interact.

• Load, unload and save polygons. You can load and unloadpolygon data associated with one or more planes and stored inone or more polygon workspaces. You can also save newpolygons to the active polygon workspace

• Display polygons and polygon attributes. You can chooseto display any combination of the following polygon elements:polygon hatch patterns, polygon labels, the polygonsthemselves, and the Polygon Information Window. The PolygonInformation Window allows you to view information about theactive polygon and working outlines, attributes associated withindividual polygons, and on-the-fly calculations such as polygonarea, volume, and tonnage for individual polygons.


• Merging and intersecting polgyons. You can create newpolgyons by merging existing polgyons from two polygonoutlines. You can also create polygons that represent the unionor the intersection of existing polgyons.

See Chapter 17: Polygons and Outlines and Chapter 18: Creatingand Working with Polygons.

The Tools Menu

The Create Plane Plots submenu on the Tools menu contains anumber of commands allowing you to create several different typesof plots projected onto the surface or onto planes.

In the case of plan views and sections, data is projectedorthogonally onto the plane from within a corridor on each side ofthe plane. These functions have been designed so that you can workwith multiple planes in one operation, using display parametersdefined and stored in external profiles.

You can use this submenu to perform the following functions:

• Select planes for plot creation. You can choose to createsurface plot files, or you can select one or more plan views,inclined sections or vertical sections. See Chapter 19: CreatingPlane Plots.

• Create symbol plots. You can display data located atindividual points defined by a coordinate. Each point can beannotated with a symbol that can vary in size and colourdependent on data values, and with selected fields from thedatabase. You can use a predetermined extraction file or theactive workspace to create these symbol plots for surface maps,plan views, vertical sections or inclined sections. SeeChapter 20: Symbol Plane Plots.

• Create drillhole plots. You can display data from anytraverse or drillhole workspace. You can then project this dataonto surface maps, plan views, inclined sections or vertical


sections using either an orthogonal projection or a projectionthat includes a correction for average trend and plunge angles.Data from any of the workspace tables can be used to annotatethe drillhole traces in a wide variety of formats: as text, asnormal or log-scaled histograms, as normal or log-scaled linegraphs, or as colour-emphasized traces. Full three-dimensionalclipping ensures that only those portions of drillholes fallinginside the projection distance are shown on each plane. SeeChapter 21: Drillhole Plane Plots.

• Create polygon plots. You can display data on surface maps,plan views, inclined sections or vertical sections from anypolygon workspace showing polygons or polylines annotatedwith data from any field. Polygons are always plotted on theplane and are not projected or transformed in any way. SeeChapter 22: Polygon Plane Plots.

• Create structure maps. You can display data on surface mapsand plan views from any type of workspace which contains acoordinate field in at least one table. Each data point isdisplayed with a special symbol that describes the geologicalstructure of the point (for example, bedding, foliation, faults,etc.). See Chapter 23: Structure Maps.

• Create grid cell and contour plots. You can produce contourmaps from regular grids of data that have been created fromdata randomly distributed in space. These grids can be orientedin any location on surface maps, plan views, vertical sectionsand inclined sections and can be created using distanceweighting techniques such as inverse distance raised to a power(IDP) or three-dimensional curve fitting (Laplace). SeeChapter 24: Gridding and Contouring.

• Create topographic surface intersections. You cancalculate the intersection of each vertical section plane with adigitized surface topography and display the intersection lineon the plotted plane. See Chapter 19: Creating Plane Plots.


• View prepared plots. Using the PRIMFILE.DAT file, you canview any of the plane plot GGP files you create with the planeplot facilities. See Chapter 19: Creating Plane Plots.

2001

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