31. The floor is formed into a structural basin by a series of geologic faults and fracture zones . 32. The northerly side is a transform boundary with the Juan de Fuca Plate, the Blanco Fracture Zone . 33. The Tydeman fracture zone ( ) between Madeira and the Azores is named after " Tydeman ". 34. The SWIR has ultra-slow spreading rates, a rough topography, and great number of large offset fracture zones . 35. The Upper Rhine Rift is part of a fracture zone reaching from the Mediterranean Sea to Norway. 36. The southern part of the Shackleton Fracture Zone is the former eastern edge of the Phoenix Plate. 37. Also known as the Romanche Trench, this fracture zone separates the North Atlantic and South Atlantic Oceans. 38. Many large fracture zones aligned in an east-west direction, occur in the floor of the northeastern Pacific. 39. However, by observing the fracture zones , one can determine both the direction and rate of past plate motion. 40. The complexity in the Tj�rnes Fracture Zone can be generally explained by the magmatic processes and plate motions.
