Caption text Geological timescale Credit NERC Key stages Key Stage 2 Key Stage 3 Key Stage 4 Key Stage 5 Higher Education Lifelong learning Themes Geology Curriculum subject Geography Science A timechart setting out the geological timescale by period, era and eon. Keywords eon era period Phanerozoic Mesozoic Palaeozoic Cambrian Ordovician Silurian Devonian carboniferous Permian Triassic Cretaceous Palaeogene Quaternary Foundations of Mendip (British Geological Survey) – Geological Timescale