Blisworth Limestone Formation today in the seas off the Bahamas (Kirkaldy p. 59). Much of it also contains marine shells, notably of oyster. Subsequently, the site was submerged less deeply so that the overlying Blisworth Clay was deposited in brackish conditions. (Gallois p. 20) The stratum is known as Blisworth Limestone because it was first studied at Blisworth in Northamptonshire when the Blisworth tunnel was being dug for what is now called the Grand Union Canal. The tunnel finally opened in 1805. Blisworth limestone is a generally thin but widely spread deposit in eastern England. It becomes thicker as one progresses southward from
Stickpile Tunnel 1975 and the rail line was abandoned that same year. Green Ridge, West Virginia, an abandoned railroad town, was located near the western portal of the tunnel, across the Potomac River. The National Park Service acquired the tunnel and adjacent portions of the WM right of way in 1980. The site is part of Chesapeake and Ohio Canal National Historical Park. Stickpile Tunnel Stickpile Tunnel, also known as Greenridge Tunnel, is an abandoned railroad tunnel in Allegany County, Maryland, located about southwest of Little Orleans. It was built by the Western Maryland Railway (WM) in 1906. It was constructed with