The area chosen for this study is 125 miles from Christchurch by way of the Lewis Pass highway. At Spring Junction the highway branches, the main route continuing to Reefton through the Victoria Range whilst the less important branch links the Lewis Pass route with Nelson via Murchison. Although the road between Springs Junction and Murchison is metalled and often in poor condition the main road is sealed and provides good travelling. The study area is immediately accessible from Christchurch. Initially, work was commenced in the areas east of Mauria, using Station Creek as a western boundary. Preliminary traverses in Coal Creek, Diggers Creek and Station Creek showed the majority of the area to be occupied by young gravels. The area for study was extended to the south-west and limited to the north by appearance of these gravels. The western boundary was taken as the Victoria Range; the eastern as the Haast Schist Group east of the Alpine Fault Zone.