Stratigraphy of the United Kingdom - Lithostratigraphy of England, London Clay, Torridonian, Old Red Sandstone, Kimmeridge Clay, Millstone Grit (Paperback)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 25. Chapters: Lithostratigraphy of England, London Clay, Torridonian, Old Red Sandstone, Kimmeridge Clay, Millstone Grit, Oxford Clay Formation, Blue Lias, Purbeck Group, Inferior Oolite, Geology of London, Lambeth Group, Wenlock Group, Totternhoe Stone, Wealden Group, Barton Beds, Corallian Oolite Formation, New Red Sandstone, Llandovery Group, Lias Group, Llandeilo Group, Speeton Beds, Bathonian Series, Roaches Grit, Lincolnshire limestone, Bala Series, Aymestry Limestone, Bovey Formation, Rough Rock, Skiddaw Slate, Pennant Measures, Warwickshire Group, Bradford Clay, Kellaways Formation. Excerpt: The London Clay Formation is a marine geological formation of Ypresian (Lower Eocene Epoch, c. 56-49 Ma) age which crops out in the southeast of England. The London Clay is well known for the fossils it contains. The fossils from the Lower Eocene indicate a moderately warm climate, the flora being tropical or subtropical. Though sea levels changed during the deposition of the Clay, the habitat was generally a lush forest - perhaps like in Indonesia or East Africa today - bordering a warm, shallow ocean. The London Clay consists of a stiff, bluish coloured clay which becomes brown when weathered. Nodular lumps of pyrite and crystals of selenite (sometimes called "waterstones") frequently occur within the clay, and large septarian concretions are also common. These have been used in the past for the manufacturing of cement. They were once dug for this purpose at Sheppey, near Sittingbourne, and at Harwich, and also dredged off the Hampshire coast. The clay itself has been used commercially for making bricks, tiles, and coarse pottery. It is infertile for gardens and crops. The London Clay is well developed in the London Basin, where it thins westwards from around 150 metres (490 ft) in Essex and north Kent to around 4.6 metres (15 ft) i...