MEGMS logo - go to the home page
  1. Home

    1. MEGS_Log

      1. MEGS_Log Downloads

      2. MEGS_Log Documentation

        1. MEGS_Log version 3.3 Help

          1. Copyright notice and licence agreement

          2. How to contact MEGS_Log support

          3. What's new in MEGS_Log 3.3

          4. Concepts in MEGS_Log

            1. About boreholes, units and elements

            2. About geophysical traces

            3. About editing with the mouse and Editing Tools

            4. About Insert Modes

            5. About schemas

            6. About seams and plies

            7. About sample numbers

            8. About hatches

            9. MEGS_Log settings

            10. About the MEGS_Log configuration file

            11. About MEGS_Log licencing

          5. How to carry out common tasks within MEGS_Log

          6. Menus and commands

          7. Window elements and dialogs

          8. List of appendices

          9. MEGS_Log version 3.3 Help Index

    2. CoalLog tools

    3. Fortran Tools

    4. Contact Us

  2. Site map

"Let's model me a mine"


Mining & Exploration Geological Modelling Services

Previous topic Parent topic Home topic Next topic

About schemas

MEGS_Log uses schemas to define the order and type of fields present within some borehole file formats.

Schemas are named and defined using the MEGS_Log config file or the Schema Editor. You can also use the schema editor to import schemas from Prolog 4.x files.

Schemas supplied with MEGS_Log

The config file installed with MEGS_Log contains a number of example schemas:


Each field in a schema has a type that determines how MEGS_Log should process the data for that field. Some fields types are only relevant for unit properties, while other field types are relevant for bot units and element properties.

A schema that is valid for use by MEGS_Log must contain at least:

Schemas that are not valid are ignored by MEGS_Log.

A schema may over-specify the depth to the bottom of each unit, for example by including both bottom and top fields. In this case MEGS_Log will check the over-specified information when loading a borehole and report errors if the values in the fields do not reconcile (for example, if the bottom of a unit is not the same depth as the top of the underlying unit).

If you want to use MEGS_Log to label units with seam names, or seam and ply names, then the schema for the borehole must have seam, or seam and ply fields.

Similarly, if you want to use MEGS_Log to label units with sample numbers, then the schema for the borehole must have a sample field.

Schemas and Prolog

When working with Prolog files there are some additional restrictions on schemas: