Diamantina Fracture Zone Diamantina Fracture Zone The Diamantina Fracture Zone is an area of the south-eastern Indian Ocean seafloor. It has a range of ridges and trenches. It lies to the south of the mideastern Indian Ocean features of the Wharton Basin and Perth Basin, and to the south west of the Naturaliste Plateau. Being parallel to the Southeast Indian Ridge, Diamantina Fracture Zone is not a real fracture zone in the sense of plate tectonics, but rather an escarpment, separating two oceanic plateaus. In fact its extension to the west is called Diamantina Escarpment. This is the southern border of the Broken
Hikurangi Trench for which the town of Kaikoura is famous. The plate boundary continues inland along the Marlborough Fault System, linking through to the Alpine Fault. Here the plates converge much more obliquely, exhibiting transpression instead of subduction. Hikurangi Trench The Hikurangi Trench, also called the Hikurangi Trough, is an oceanic trench in the bed of the Pacific Ocean off the east coast of the North Island of New Zealand, lying between the southern end of the Cook Strait and the Chatham Rise. It is the southward continuation of the much deeper Kermadec Trench. It lies in the Hikurangi Margin subduction zone,