Silurian and Cambrian systems (Murchison and Sedgwick)
Sistemas Silúrico y Cámbrico (Murchison y Sedgwick)
- Date
- 1835 · confidence high
- Place
- Llandovery, Carmarthenshire, Wales, United Kingdom
- Credited to
- Roderick Murchison and Adam Sedgwick
- Field
- Cosmos & Earth
⚠️ Disputed: the sources disagree.
What was discovered
Murchison defined the Silurian (1835) in the fossiliferous strata of the Welsh Borders and Sedgwick the Cambrian in North Wales; this filled the gap between the Precambrian and the Devonian in the scale. Their overlapping limits provoked a quarrel that Lapworth ended in 1879 with the Ordovician.
Both presented their systems in 1835 at the Geological Society; their rivalry lasted until Sedgwick's death (1873). The place is the Silurian type area.
What it led to
- subdivision of the Palaeozoic by fossils
- a classic boundary dispute resolved by a new unit (the Ordovician)