Hayward, B.W. 1979 Ancient undersea volcanoes : a guide to the geological formations at Muriwai, West Auckland. Lower Hutt: Geological Society of New Zealand. Geological Society of New Zealand guidebook 3. 32 p.
Abstract: Muriwai is on the stormy Tasman Sea coast at the north end of the Waitakere Ranges, 30 km west of Auckland City. Muriwai Beach is a long exposed strip of black sand, well-known for its surfing and toheroas. It stretches northwards for 50 km to the mouth of the Kaipara Harbour. South of Muriwai, the coastline is cliffed with small, sandy beaches separated by rocky points. These cliffs contain some of the most spectacular and best preserved examples found anywhere in the world of geological formations known as pillow lavas. The pillow lavas were formed by undersea volcanic eruptions during the geological epoch of the early Miocene about 17 million years ago. They are overlain near the top of the cliffs by much softer rocks (orange-stained sandstones) that formed more recently during the Pleistocene epoch (ice ages), about 500,000 years ago. (auth)
