The Geology of the Makara and Ruakokopatuna Valleys, East Wairarapa

Abstract

The area investigated lies to the north-east of the Haurangi Mountains in the Waipawa and Haurangi Survey Districts, East Wairarapa, approximately 5 miles due south of Martinborough. The area mapped is approximately 50 square miles (see Fig. 1). The purpose of the investigation was to examine in detail the fossiliferous Tertiary rocks exposed in the Makara and Manga-o-pari Valleys and to attempt to interpret the geological history of this area. It was found, however, that this history was more complicated than would appear at first sight and a larger area than was first planned had to be investigated in order to gain a clearer idea of the regional structure. Thus, it should be noted here that Map 2 represents an area which has been closely investigated, while the geological features mapped around the Ruakokopatuna River, Dry River and the Blue Rock Stream are the results of a mere rapid and less detailed examination. For the sake of completeness, the area mapped by R. J. Waghorn (1926) is included in Map 1. This area was also investigated by the writer and the sediments, as mapped by Waghorn, found to be substantially correct, although as pointed out below, the age determinations have to be modified in the light of later palaeontological knowledge.