Subophitic
An igneous texture in which plagioclase laths are partially, rather than wholly, enclosed by clinopyroxene.
Language and route: English sub- prefix joined to ophitic, itself from ophite (ultimately Greek). English sub- prefix joined to ophitic, itself from ophite (ultimately Greek)
Literal gloss: less than fully ophitic
The name and its history
No securely established individual first coiner · First geological printed use not established
- What does the word literally mean?
- Immediate route: English sub- prefix joined to ophitic, itself from ophite (ultimately Greek). Linguistic gloss: ‘less than fully ophitic’. This gloss describes language, not a demonstrated early geological theory.
- What did the original author mean?
- This qualifying term was adopted to subdivide petrographic relationships previously lumped under broad diabasic or ophitic descriptions; its first publication remains unresolved.
- Why was the name needed?
- Observers needed a term for incomplete feldspar enclosure visible in basaltic or doleritic thin sections.
- What evidence supported the original concept?
- Optical continuity of individual pyroxenes and variable proportions of plagioclase laths inside versus projecting beyond those grains.
- How has geology changed the concept?
- Modern IODP codes distinguish subophitic from ophitic explicitly; the boundaries are descriptive rather than independent rock types.
Further historical context
This qualifying term was adopted to subdivide petrographic relationships previously lumped under broad diabasic or ophitic descriptions; its first publication remains unresolved.
Observers needed a term for incomplete feldspar enclosure visible in basaltic or doleritic thin sections.
Optical continuity of individual pyroxenes and variable proportions of plagioclase laths inside versus projecting beyond those grains.
Modern IODP codes distinguish subophitic from ophitic explicitly; the boundaries are descriptive rather than independent rock types.
Editorial qualification
The first naming act and earliest printed use have not been verified; this is an editorial reconstruction of historical need.
Related names
Sources
- International Ocean Discovery Program, Expedition 360 methods — Operational definitions for igneous groundmass, flow and inclusion textures
- Geological Survey of India, Rock Texture Atlas — Photomicrographs and modern texture definitions