Interactive ternary plot for visualizing volcanic rock classification based on normalized Crystal, Glass, and Vesicle components.
This tool provides an interactive web-based ternary diagram for classifying and visualizing volcanic rocks according to their normalized proportions of:
- Crystal (solid phases or differentiation signatures)
- Glass (amorphous phase of solidified melt)
- Vesicle (exsolved volatile or porosity)
The classification scheme is inspired by seminal work in volcanology and petrology:
- Fisher (1966) — Foundational ternary classification framework
- Schmid (1981) — Refinements in volcanic rock nomenclature
- Pettijohn et al. (1975) — Sedimentary rock classification principles adapted for volcanic materials
- Interactive Ternary Plotting: Add sample points with real-time visualization
- Natural Field Boundaries: Pre-defined classification fields for common volcanic rock types:
- Obsidian, Dense Lavas, Scoriae, Pumices, Reticulites
- Tachylite/Sideromelane, Vitrophyres, Porphyritic Lavas
- Hyaloclastites/Palagonite, Cumulates
- Dynamic Validation: Automatic sum validation (must equal 100%)
- Normalized Input Sliders: Easy adjustment of Crystal, Glass, and Vesicle percentages
- Sample Management: Add, delete, and track multiple sample points
- Export Capabilities:
- Download plots as PNG images
- Export sample data as CSV
- Dark Theme UI: Professional, publication-ready dark interface
- Responsive Design: Works on desktop and tablet displays
- Hover Tooltips: Quick access to sample composition details
- Visit the app: https://tdisando.github.io/CGV_ternary/
- Add a sample:
- Enter a sample name (e.g., "BAS-01", "PUM-03")
- Adjust sliders for Crystal, Glass, and Vesicle percentages
- Ensure total = 100%
- Click "▸ Plot Sample"
- Visualize: Points appear on the ternary diagram, color-coded and labeled
- Manage: Delete individual samples or clear all
- Export: Download PNG or CSV for further analysis
The diagram includes 10 natural volcanic rock classification fields (rough estimation):
| Field | Characteristics |
|---|---|
| Obsidian | High glass (>90%), minimal crystals/vesicles |
| Dense Lavas | Crystalline basalt/andesite; low vesicularity |
| Scoriae | Moderate crystal + vesicle; intermediate porosity |
| Pumices | High vesicularity (>60%); low crystal |
| Reticulites | Extreme vesicularity (>85%); minimal other phases |
| Tachylite/Sideromelane | High glass with minor vesicles; deep-water basalt |
| Vitrophyres | Crystalline with glassy matrix; transitional |
| Porphyritic Lavas | Significant crystals in glassy groundmass |
| Hyaloclastites/Palagonite | Mixed glass + vesicles; alteration products |
| Cumulates | Highly crystalline (>80%); crystal-rich phases |
The ternary diagram uses an equilateral triangle where:
- Bottom-left corner = 100% Crystal
- Bottom-right corner = 100% Glass
- Top corner = 100% Vesicle
Coordinates are normalized such that Crystal + Glass + Vesicle = 100%.
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Fisher, R. V. (1966). "Geology of the Crater Lake Caldera, Oregon." U.S. Geological Survey Professional Paper, 513. https://doi.org/10.1016/0012-8252(66)90010-9
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Schmid, R. (1981). "Descriptive nomenclature and classification of pyroclastic deposits and fragments: Recommendations of the IUGS Subcommission on the Systematics of Igneous Rocks." Journal of Volcanology and Geothermal Research, 8(3-4). https://doi.org/10.1007/BF01822152
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Pettijohn, F. J., Potter, P. E., & Siever, R. (1975). Sand and Sandstone (2nd ed.). Springer-Verlag. https://doi.org/10.1007/978-1-4612-1066-5
This project is licensed under the MIT License — see LICENSE file for details.
You are free to:
- Use commercially and privately
- Modify the source code
- Distribute copies
You must:
- Include the license and copyright notice
- Inspired by classic volcanology literature and the IUGS nomenclature system
- Built for geologists, volcanologists, and petrology researchers
- Special thanks to all contributors and users providing feedback
Made with ❤️ for the volcanology community