Mansergh, G.D. 1974 State Highway 73 realignment, Broken River, S66. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EG 184 7 p.
Abstract: A request was received from M.O.W. Christchurch for geological comment on the country between Castle Hill Station and Parapet Rock to assist in the selection of a new alignment for SH 73. Several areas of instability are recognised in the area and the geological work has been aimed at determining the distribution of potentially unstable areas. Two half days were spent mapping in the area, mainly in the Broken River Valley, and cores or disturbed samples from eight exploratory holes put down by M.O.W. were inspected. Logs were obtained from M.O.W. for a further 3three holes. The whole of the Broken River Basin was mapped by Gage (1970) and more detailed work has been done in the immediate area of the proposed alignment by Dr Bradshaw of Canterbury University. This report relies heavily on the data of these workers. (auth)
