Microanalysis of planation surfaces in the Port Nicholson Basin (Wellington City), and relationship of tectonic features

Abstract

Abstract A large number of discrete planation levels, with a superimposed pattern of dominant levels, are identified in the Wellington City area of Port Nicholson. These dominant levels are related to marine terraces to the west of the harbour on the outer coast. Many of these planation surfaces, assumed to be marine terraces, are cut into Late Quaternary deposits which are found up to about 200 ft (61 m), but higher terraces are identified up to 582 ft (177 m) cut into basement greywacke. The pattern of dominant levels can be seen in a number of localities of Late Pleistocene age outside the area. There is a noticeable absence of levels between 61 m and 73 m. The data suggest a relatively stable Late Quaternary period between the earlier major folding along the Wellington Fault which formed the basin, and recent tectonic movements.