Huia Pt Lookout

This lookout provides panoramic views across Huia Bay and the Manukau Harbour and is a great place to get a feel for how this part of Auckland was formed.
Just across Huia Bay are the majestic rocky bluffs of the Karamatura Valley in the Waitakere Ranges and to their south (left) is Marama Valley with conical Te Komoki Peak and at the head of Huia Bay is the Huia Valley (right). All the high hills and bluffs you can see across the bay are composed of volcanic conglomerate that was deposited on the submarine slopes of the growing Waitakere Volcano about 20-18 million years ago. The Waitakere Volcano became the largest cone volcano in New Zealand's history having a base 60 km from west to east and 40 km from north to south. Since it stopped erupting 15 million years ago, most of it has been eroded away by the Tasman Sea and its eastern slopes have been uplifted to form the present day Waitakere Ranges.
To the southwest you can see the entrance to the Manukau Harbour - one of New Zealand's largest harbours. To the south is the northern tip of the Awhitu Peninsula which is a sand barrier that was built across the entrance to Manukau Bay over the last 2 million years. The growth of the sand barrier created the sheltered Manukau Harbour in behind. The sand for the barrier came from erosion of Taranaki Volcano and particularly from the large eruptions in the centre of the North Island in the last 1.6 million years.

The Manukau Harbour is mostly shallower than 10 m deep. During the climate cycles of the last 2 million years sea level has been lower than this for more than 80% of the time during each cold glacial (Ice Age) period. There have been more than 30 separate glacial periods in the last 2 million years each separated by a warmer interglacial when sea level would have been close to the present. Thus there have been more than 30 separate Manukau Harbours in this time.
Try to imagine what the Manukau Harbour in front of you would have looked like during each cold period.
Use the shape of Awhitu Peninsula to infer which way sand is moving up the west coast.
Why has the Awhitu sand barrier not linked across to the Waitakere Ranges?
Imagine what it would have been like on this spot 19 million years ago and how far would you have had to walk uphill before you could take a breath of fresh air?