Paterson, B.R. 1972 Tangarakau Gorge bridge replacement proposal - a geological investigation. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EG 140 11 p.
Abstract: Following a request by the Resident Engineer, Ministry of Works, Taumarunui, a geological report has been prepared on the site of proposed earthworks on State Highway 43, in the Tangarakau Gorge. The investigation was to include such aspects as erodibility of the rock in a proposed river diversion and the appraisal of any faults present. The proposal included a short diversion of the Tangarakau River, eliminating a large prominent loop in the river course, and the realignment of a section of the road. This proposal is alternative to the necessary replacement of the two existing single carriageway bridges that span the river at the narrow neck of the loop. In accordance with Ministry of Works policy the replacement bridges would have to be dual carriageway structures. The geological investigations for this report include four days fieldwork and several hours logging the core from 3 investigation drill holes. (auth)