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
Maida Hill Tunnel Venice and Camden Locks, passing through the tunnel and calling at the zoo, and the tunnel is only wide enough for one way traffic. Boats are therefore required to give way if another boat is approaching in the opposite direction. In 2016 the Canal River Trust provisionally opened access to non-powerfed craft such as kayaks, packrafts and canoes. Maida Hill Tunnel Maida Hill Tunnel is a canal tunnel on the Regent's Canal in London, England. The two other tunnels on the Regent's Canal are Islington Tunnel and Eyre's tunnel. The Regent's Canal was authorised by an Act of Parliament in