Blisworth Limestone Formation relationship to the Jurassic ridge, to the west of Peterborough. (BGS sheet 157) Around Towcester it reaches a thickness of 9m. (Hains & Horton p. 85) Blisworth limestone is used as a building material, in particular as blocks of stone. Lilford Hall in Northamptonshire is made from Blisworth limestone. Blisworth Limestone Formation The Blisworth Limestone Formation is a geological formation primarily consisting of limestone deposited during the Bathonian stage of the Middle Jurassic, found in the Jurassic ridge which extends north and south through England. It was laid down in the shallows of the Jurassic sea and is part of
Pennsylvania Canal Tunnel but that canal never reached its expected western end, and the tunnel's main use was to allow overflow from the canal to enter the Monongahela. Only one or two canal boats ever went through the tunnel and lock. The tunnel was made obsolete by the arrival of the Pennsylvania Railroad in 1852. The canal tunnel was uncovered during the construction of the U.S. Steel Tower in 1967, and later during the construction of the subway system, which used part of the tunnel on the south side. Pennsylvania Canal Tunnel The Pennsylvania Canal Tunnel was the Pittsburgh terminus of the Pennsylvania