hypabyssal
/ˌhaɪpəˈbɪsəl/
adjective
- Describing a type of igneous rock that formed at a medium depth below the Earth's surface, between volcanic and deep plutonic rocks.
- The sample had crystals that were larger than volcanic glass but smaller than deep granite, typical of hypabyssal rock.
- The geologist identified the rock as hypabyssal because of its fine-grained texture.
- Hypabyssal rocks often form in cracks and small chambers near the surface.