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
Rove Tunnel Rove Tunnel The Rove Tunnel is a canal tunnel in France that connected Marseille to the Rhône river. It was opened in 1927 and closed in 1963. With a length of it was a major work of civil engineering and one of the longest such tunnels. The tunnel was the most challenging section of the Canal de Marseille au Rhône, which connected Marseille to the Rhône river. The canal has a total length of . The tunnel starts near the village of Le Rove, and runs through the Chaîne de l'Estaque at sea level. The tunnel is long, wide and