Volcanic origin of basalt in the Auvergne (Guettard and Desmarest)
Origen volcánico del basalto en la Auvernia (Guettard y Desmarest)
- Date
- 1751-1774 · confidence high
- Place
- Clermont-Ferrand, Puy-de-Dôme, France
- Credited to
- Jean-Étienne Guettard and Nicolas Desmarest
- Field
- Cosmos & Earth
What was discovered
Guettard recognised in 1751 that the puys of the Auvergne were extinct volcanoes, and Desmarest showed between 1763 and 1774 that basalt columns were solidified lava, mapping the flows and ordering them by age. It was a decisive blow to Neptunism.
Desmarest presented his results in 1763-1771 and published them in 1774; Guettard identified the volcanoes without attributing basalt to them until Desmarest.
What it led to
- the basalt controversy between Neptunists and Plutonists
- the discovery of extinct volcanoes as a reconstruction of Earth's past