Autochthonous rocks from the Chatham Rise, east of New Zealand

Abstract

Certain rocks, obtained by dredging in the central region of the Chatham Rise, are considered to occur in situ or to be derived from sources nearby. It is possible to distinguish them from ice-rafted, erratic rock fragments previously described from the same area. Details are given of the autochthonous rocks, and their significance with respect to the structure of the Chatham Rise is bridly discussed. Some of the rocks occur on, or close to, a newly discovered shallow submarine ridge, here named the Matheson Bank.