Rhyolite | A soil type defined by John Szabo (2016, p.248) as ‘predominantly extrusive igneous rock, with more that 60 per cent silica (felsic), high in potassium and sodium, and low in iron and magnesium. Eruptions featuring Rhyolite are most often explosive, thanks to its lower melting point and high viscosity.

Bibliography

John Szabo (MS), Volcanic Wines, (Jacqui Small, 2016).

Trachyte | A soil type defined by John Szabo (2016, p.248) as ‘a fine-grained, alkaline, (basic) extrusive igneous rock rich in feldspars, between rhyolite and dacite in silica content.’

Bibliography

John Szabo (MS), Volcanic Wines, (Jacqui Small, 2016).