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Version: 3.4.20 (unreleased)

Logging: Schemes, Fills, Class Tracks and Templates

How a log looks and which lists it draws from. Digitising a log and editing its beds is in Geological Logging.

Lithology fill styles​

A lithology can have a Pattern Fill as a facies can: a hatch tile drawn over its colour in its share of the Lithology track, and in the SVG and PDF exports. Choose it on the lithology's properties (Collections > Lithologies), from the same pattern library as the facies tiles. VRGS ships a set of 33 seamless lithology tiles — clay, silt, sand, gravel, mudstone, shale, sandstone, conglomerate, limestone, dolostone, chalk, chert, gypsum, halite, coal, the igneous and metamorphic rocks — as the Original Fill Styles group of the pattern library, beside the FGDC standard patterns, each group organised by rock class.

A lithology named as one of those tiles takes it without being asked: Sandstone, Mudstone, Limestone and Coal in a new project come with their fills, and an older project's lithologies pick theirs up when the project opens. Add from Library on the Lithologies folder adds the 33 as lithologies, each with its tile. A scheme file carries a lithology's pattern too.

Logging schemes​

A new project's lists — facies, lithologies, sedimentary structures, fossils, base contacts and grain-size classes — start empty. A logging scheme is all of them in one file (.vrgsscheme.json), to take from one project to the next, share round a department, or start a new project from.

Right-click Facies in the Collections tree:

  • Import Logging Scheme... adds what the file has that your project lacks, by name (the case does not matter), and leaves what the project already has as it is: a scheme never changes a colour or a pattern you have chosen. The messages panel says what was added. In a project with no facies yet, the dialog opens on the schemes shipped with VRGS, in LIBRARY\SCHEMES beside VRGS.exe.
  • Export Logging Scheme... writes your project's lists as a scheme: each facies with its colour, pattern tile and association; each lithology, structure and fossil with its colour and symbol; each contact with its line; each grain-size class with its bounds.

VRGS ships Fluvial lithofacies (Miall): Miall's lithofacies codes in channel and overbank associations, with the lithologies, structures, fossils, contacts and Wentworth grain-size classes a fluvial section is logged with. The scheme's codes are what the Quick Log matches, so a line like 0.4 St fs/ms tcb erosive reads straight in.

The file is plain JSON, so a scheme can be written or edited by hand: a facies entry is {"name": "St", "colour": "#f0c860", "pattern": "...", "association": "Channel"}; a structure or fossil {"name": "...", "symbol": "..."}, the symbol being a name in the Icons collection; a contact {"name": "Erosive", "line": "Scalloped"}; a grain size {"name": "Fine Sand", "min_mm": 0.125, "max_mm": 0.25}.

Class tracks​

A class track draws, bed by bed, what each bed holds from one of the project's class lists: a column per class, the class's colour down each bed that holds it, and its symbol over it. Sedimentary Structures and Palaeontology are class tracks, and so is a track of any list under Generic Classes in the Collections tree: carbonate textures, mineralisation, alteration, structural geology, outcrop annotations, or a list of your own. Right-click the background of a 2D log view and choose Add Class Track to add one.

On a class track's properties:

  • Columns — Classes the Log Holds gives a column to each class the log's beds hold; Every Class gives one to every class of the list, held or not, a fixed scale with the same columns on every log. A structures or fossil track starts with the first, a generic track with the second.
  • Groups Shown — tick the groups of the list the track shows. One list can feed several focused tracks: a structures track of cross bedding alone, or a mineralisation list drawn as one track of ore styles and another of alteration. A class in no group shows only when every group is ticked.

A class is drawn in its list entry's colour and with its symbol, so a change made on the entry's properties shows on every log at once.

Generic class lists​

A generic class list's entries have a Colour, a Symbol and a Group, as fossils and structures do, all saved with the project. Its Values property says what a bed gives each class it holds besides holding it:

  • None — a class is held or not.
  • Abundance — present, rare, common or abundant, written r, c or a beside the class, as a fossil's abundance is.
  • Intensity — present, weak, moderate or strong, written w, m or s: the way mineralisation and alteration are usually logged.

To set a bed's value, right-click the bed on the track and choose the class under Abundance or Intensity; the selected beds that hold the class all take it, as one step of undo. A fossil's abundance can be set the same way on the Palaeontology track.

New List from Library​

The pattern and symbol library ships folders that no fixed collection takes: structural geology, geological boundaries and map lines, mineralisation and exploration, digital outcrop annotations, and geomorphology. Right-click Generic Classes and choose New List from Library, then a folder: VRGS makes a list named after it, with a class for each of its symbols, in the library's order and grouped by its sub-folders, each drawing its symbol. Set the list's Values if its classes are graded, then add it as a class track. Folders you add to your own LIBRARY\SYMBOLS are offered too.

Log templates​

A log template controls how a log is drawn — which tracks appear, in what order, at what widths. Templates live in the Collections tree under Log Templates, and the 2D Log tab's template dropdown picks the active one plus lets you create a new one.

Set a template up once for the study and every log drawn afterwards matches, which is what makes a correlation panel readable.

To use a template in another project, right-click it under Log Templates and choose Export Template... to write it to a .json file. Then right-click Log Templates in the other project and choose Import Template.... A generic-class track names a class list by number, so it draws nothing in a project without that list until you choose one.

Remove Track and Swap Track can be undone with Ctrl+Z, as can placing, dragging and deleting a correlation pick.