DevonianThe Devonian (dᵻ'voʊni.ən,_dɛ- ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Ma), to the beginning of the Carboniferous, Ma. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents.
DevonDevon (ˈdɛvən , historically also known as Devonshire -ʃɪər,_-ʃər , ) is a ceremonial county in South West England. The county borders the Bristol Channel to the north, Somerset and Dorset to the east, the English Channel to the south, and Cornwall to the west. Plymouth is the largest settlement. The county has an area of and a population of 1,194,166. The largest settlements after Plymouth (264,695) are the city of Exeter (130,709) and the seaside resorts of Torquay and Paignton, which have a combined population of 115,410.
Sedimentary rockSedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus (organic matter). The geological detritus originated from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes.
