A Paleoenvironmental Interpretation of the Pukenui Limestone and Hautotara Formation, Southeastern Wairarapa, New Zealand
Two sections from the northern part of the Nga-Waka-A-Kupe Range have been documented in detail. Both sections were expected to cut through sediments of Pleistocene age which at the southern end of the range have been attributed to the Greycliffs Formation, Pukenui Limestone, Hautotara and Te Muna Formations. The Longbush Road section only included the upper Pukenui Limestone to Hautotara Formation. The Hinakura Road section was as expected and included the entire Pukenui Limestone and Hautotara Formation. Previous works in the Popes Head area have recognised the same sequence there. However, only a few correlations can confidently be made between the two areas. This is largely due to the Pukenui Limestone at Popes Head exhibiting a markedly different set of facies to the section in the southern part of the range – its type section. The facies analysis on the two sections here reveals that the depositional environment for the Pukenui Limestone in the Popes Head area is of a near-coastal environment close to the discharge of a large river, where the nearby type section is interpreted as representing deeper marine conditions. The differences in environments could be due to shallowing section or increased discharge from the river in the Popes Head area. More likely, however, it is a combination of these two factors that result in a shallow-water facies.