Tuesday, 12 March 2013
Titahi Bay Geology
GNS Science website .
Having looked at the erosion and weathering features along the coast, the next thing to do is have a look at the structures and the rocks themselves.
In this photo you can see that the rocks are made up of alternating bands of massive sandstone, with in-between layers of dark mudstone. These rocks were formed from sands and muds eroded from the margin of Gondwanaland, long before New Zealand existed. The material flowed down into the deep sea and settled over wide areas. The coarser sediment, at the base of each of these submarine landslides, is represented by the sandstone, whilst the mudstone gradually settled on top.