https://github.com/MadsLorentzen/superposed-folds
Interactive Python toolkit for visualizing superposed folds (Ramsay & Lisle 2000; Grasemann et al. 2004). Python port of UCD's MATLAB educational resource.
https://github.com/MadsLorentzen/superposed-folds
Last synced: 2 months ago
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Interactive Python toolkit for visualizing superposed folds (Ramsay & Lisle 2000; Grasemann et al. 2004). Python port of UCD's MATLAB educational resource.
- Host: GitHub
- URL: https://github.com/MadsLorentzen/superposed-folds
- Owner: MadsLorentzen
- License: mit
- Created: 2026-05-04T14:04:29.000Z (3 months ago)
- Default Branch: main
- Last Pushed: 2026-05-20T15:38:44.000Z (2 months ago)
- Last Synced: 2026-05-20T19:36:49.965Z (2 months ago)
- Language: Python
- Size: 21.4 MB
- Stars: 3
- Watchers: 0
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Citation: CITATION.cff
Awesome Lists containing this project
- awesome-open-geoscience - superposed-folds - strain equations and the Grasemann et al. (2004) classification, ported from Martin Schöpfer's UCD papermodels. (Software / Structural Geology)
README
# superposed-folds
Interactive Python toolkit for visualizing superposed folds. A modern Python
port of Martin Schöpfer's MATLAB papermodel resource at the
[UCD Fault Analysis Group](https://www.fault-analysis-group.ucd.ie/SuperPosedFolds/Superposed_PM_Index.html),
implementing the plane-strain superposed-folding equations from Ramsay & Lisle
(2000) and the extended Grasemann et al. (2004) classification.
[](https://superposed-folds.streamlit.app/)
Pick a Grasemann (2004) preset on the left or move the sliders to explore
custom amplitudes, stretches, wavelengths, and F2 orientations. The 3D
fold stack, the 2D interference map at z = 0, the stereonet, and the
classification readout all update together. Toggle the block-diagram cube
view to render the model as a painted ±5 km box (Schöpfer papermodel style)
instead of separate layer horizons. Optionally enable a cylindrical drill
core to see the same interference pattern intersecting a borehole at any
collar position, azimuth, and plunge, rendered both embedded in the 3D
view and unrolled flat as a depth-vs-circumference strip.
## What's inside
- A small Python library (`superposed_folds`) implementing:
- `FoldParameters` (amplitude, stretch, orientation, wavelength) and
the Ramsay & Lisle plane-strain equations
- Forward (`apply_superposed_fold`) and inverse (`initial_z_at`) maps
- All 21 canonical Grasemann (2004) preset configurations
- `DrillCoreParameters` and `sample_layers_on_cylinder` for sampling the
folded model on the curved surface of a cylindrical borehole at any
orientation
- Plotly figure builders: 3D fold stack with optional drill-core trace,
2D interference map at z = 0 with optional collar/line/toe overlay,
stereonet, an unrolled drill-core section, and a painted-cube block
diagram (Schöpfer papermodel style) that paints the deformed layer
pattern on each face of the ±5 km model domain
- A Streamlit app (`streamlit_app.py`) for the interactive playground.
- pytest suite with parity checks against the original UCD MATLAB code.
## Install
```bash
git clone
cd superposed-folds
uv venv
uv pip install -e ".[app,dev]"
```
## Run the web app locally
```bash
uv run streamlit run streamlit_app.py
```
## Run the tests
```bash
uv run pytest
```
## Credits and references
- **Original MATLAB resource and educational content**: Martin Schöpfer, UCD Fault Analysis Group ([page](https://www.fault-analysis-group.ucd.ie/SuperPosedFolds/Superposed_PM_Index.html))
- **Plane-strain equations**: Ramsay, J. G. and Lisle, R. J. (2000) *The Techniques of Modern Structural Geology, Volume 3*. Academic Press, p. 955.
- **Classification (original)**: Ramsay, J. G. (1962) *J. Geol.* 70, 466-481.
- **Classification (extended)**: Grasemann, B. et al. (2004) *J. Geol.* 112, 119-125.
- Project surfaced via the [Software Underground](https://softwareunderground.org) Mattermost.
## License
MIT. See `LICENSE`.