Reference Data
Gneisswork ships with pre-seeded geological classification data that populates dropdown menus throughout the application. This data is inserted on first run if the reference tables are empty. The default reference data is fully compatible with the standard symbol libraries used in SedLog (Zervas et al., 2009), ensuring that CSV exports can be visualized directly without custom symbol setup.
Source: sedmob/seed.py
Lithology Types & Lithologies
Lithologies are organized into groups:
Basic (Group 1)
| Lithology |
| Mudstone |
| Claystone |
| Shale |
| Siltstone |
| Sandstone |
| Conglomerate |
| Coal |
| Limestone |
| Chert |
| Volcaniclastic |
Carbonates (Group 2)
| Lithology |
| Lime mudstone |
| Wackestone |
| Packstone |
| Grainstone |
| Halite |
| Gypsum/Anhydrite |
| Dolomite |
Other (Group 3)
| Lithology |
| Breccia |
| Matrix-supported conglomerate |
| Clast-supported conglomerate |
| Lava |
| Fine ash |
| Coarse ash |
Structure Types & Structures
Sedimentary Structures (Group 1)
| Structure |
| Current ripple cross-lamination |
| Wave ripple cross-lamination |
| Planar cross bedding |
| Trough cross bedding |
| Horizontal planar lamination |
| Hummocky cross stratification |
| Swaley cross stratification |
| Mudcracks |
| Synaeresis cracks |
| Convolute lamination |
| Load casts |
| Water structures |
| Herring-bone cross bedding |
Fossils (Group 2)
| Structure |
| Shells |
| Bivalves |
| Gastropods |
| Cephalopods |
| Brachiopods |
| Echinoids |
| Crinoids |
| Solitary corals |
| Colonial corals |
| Foraminifera |
| Algae |
| Bryozoa |
| Stromatolites |
| Vertebrates |
| Plant material |
| Roots |
| Logs |
| Tree stumps |
| Ostracods |
| Radiolaria |
| Sponges |
Trace Fossils (Group 3)
| Structure |
| Minor bioturbation |
| Moderate bioturbation |
| Intense bioturbation |
| Tracks |
| Trails |
| Vertical burrows |
| Horizontal burrows |
Other (Group 4)
| Structure |
| Nodules and concretions |
| Intraclasts |
| Mudclasts |
| Flute marks |
| Groove marks |
| Scours |
Clastic Grain Sizes
Uses the Wentworth grain size scale with phi (φ) values:
| Name |
Phi (φ) |
| clay |
10.0 |
| clay/silt |
8.0 |
| silt |
6.0 |
| silt/vf |
4.0 |
| vf |
3.5 |
| vf/f |
3.0 |
| f |
2.5 |
| f/m |
2.0 |
| m |
1.5 |
| m/c |
1.0 |
| c |
0.5 |
| c/vc |
0.0 |
| vc |
-0.5 |
| vc/granule |
-1.0 |
| granule |
-1.5 |
| granule/pebble |
-2.3 |
| pebble |
-3.0 |
| pebble/cobble |
-4.5 |
| cobble |
-6.0 |
| cobble/boulder |
-8.0 |
| boulder |
-10.0 |
Abbreviations: vf = very fine, f = fine, m = medium, c = coarse, vc = very coarse
Carbonate Grain Sizes
Based on the Dunham classification:
| Name |
Phi (φ) |
| mudstone |
6.0 |
| wackestone |
3.5 |
| packstone |
1.5 |
| grainstone |
-0.5 |
| rudstone fine |
-1.5 |
| rudstone medium |
-3.0 |
| rudstone |
-6.0 |
Bioturbation Types
| Type |
| Minor bioturbation |
| Moderate bioturbation |
| Intense bioturbation |
| Tracks |
| Trails |
| Vertical burrows |
| Horizontal burrows |
Boundary Types
| Type |
| Sharp |
| Erosion |
| Gradational |
Customization
Reference data can be managed through the web UI at /reference:
- Add new lithologies to existing groups or create new groups
- Add new structures to existing groups or create new groups
- Rename individual lithologies and structures inline
- Rename lithology and structure groups inline
- Delete individual lithologies or structures
- Delete entire lithology or structure groups (cascades to all items in the group)
Validation rules:
- Names must contain only letters, digits, and spaces
- Duplicate names within the same table are rejected
- Renaming to the current name is allowed (no-op)
- Deleting a lithology or structure does not affect existing bed records (beds store values by name, not by foreign key)
- Deleting a group removes the group and all its child items
SedLog interoperability: Custom lithologies and structures added in Gneisswork must use the same names as their counterparts in SedLog for CSV exports to render correctly. SedLog also requires corresponding image files for custom symbols to generate graphic logs (see Wolniewicz, 2014).
Note: Grain sizes, bioturbation types, and boundaries are currently only editable via the database directly or by modifying seed.py before first run.