The Ecology of the Hutt Valley: Geology of the Hutt Valley
Within the watershed of the Hutt Valley there are only two periods of sedimentation; a very long hiatus separates them.
These two groups are (1) the very sparsely fossiliferous Mesozoic greywackes, and (2) the Quaternary terrestrial and estuarine sediments of the Hutt Valley.
Very little is known about the greywackes of the Wellington district. The folding is intensely complex in most areas and some at least have been folded in several directions. The strikes are erratic in the Fitzherbert-Wainuiomata ridge.