You are currently viewing The beaches of Piha and Karekare
Plage de Phia

The beaches of Piha and Karekare

The Piha and Karekare Beach lie in the Waitakere reserve, to the West of Auckland. Taking the train heading West and stopping at stations from Sunnyvale, it is very easy to reach the nature reserve. The stop is a very good way to reach the beaches (maximum 10 min wait). The Waitakere reserve is ideal for getting rid of Auckland city and be forgotten in the nature for many days.

For all definitions: go to this page.
For the time scale is here!



The beauty of the beaches in a hike

Karekare Beach

Beautiful place, of great beauty, she is also originally from many wars. In 1825 the Karekare Beach has been the site of an important massacre of local Maori, St.Petersburg by an enemy tribe. This beach is on the West Coast, she suffered directly the sea currents of the Pacific Ocean from the East. That’s why the beach is regarded as one of the most dangerous in the country. It is strongly recommended to bathe or to surf without a lifeguard present. But this is what she is pretty!


Karekare Beach

After visiting the beach, you can take the hiking trail that goes directly to the beach of Piha. On this hike, we take the altitude to observe the Karekare beach. You’ll reach the cliffs of Karekare, one of the most beautiful hikes in the Park. The hike takes about 2 hours to get to Piha and allows you to see beautiful landscape as well as waterfalls of Kitakita.

Hiking Piha
Hike KareKare to Piha through the cliffs. (Card:


To get the maps of the New Zealand hikes! Go on:

Piha Beach

Piha beach is one of the most popular in Auckland. During the days off, you will see many families, young, etc… come to the beach to enjoy the scenery and sunset. Arrival via the Piha Road is beautiful, it descends along the mountains to reach the beach. In the middle of the beach is located the rock of Lyon, a relic of ancient volcanic activity. Like its neighbour Piha beach is a beach with dangerous currents. Be very careful when we swim or surf and always ensure the presence of a lifeguard.

Piha Beach


Geology setting


Rugged Piha and its surrounding landscapes were created by volcanic activity there millions of years ago. A submarine volcano, the volcano Waitakere, 5 or 6 times the size of Ngaruahoe, Ruapehu and Tongariro combined. There were 20 km West on the sides of Waitaker of today and shook all the 6 to 7 million, piercing the waves as an island. Today, what we see of the reserve of Waitakere are eroded the old volcano flanks. The rest of the volcano has been gradually eroded by the sea. Around Piha Beach, it is possible to notice a large number of craters, White’s Beach, Karekare, and Mercer Bay.

The beaches of Piha and Karekare have the particularity of being composed of black sand. This sand comes from the erosion of the volcanic rocks, specifically the basalt. The volcanic rocks eroded by wind and rain, are transported by the water currents and wind up the sea.

Different stages of erosion

The sea via (the waves) swell and currents, will drop volcanic sediment on the beaches to forming the black beaches that can be observed.

Karekare beach with its black sand from the erosion of the volcanic rocks


There are also around the beach of Piha of the dikes. The dikes are relics of the back of the magma in cracks. For many years, the rock around the dike begins to erode to reveal the dikes (more resistant to erosion). After many years, he remains more than magmatic rock, the rest of the mountain surrounding it disappeared. And thus appears these so imposing dikes of tens to hundreds of metres in height.

Formation of a dike in the sediments. Up from the lava in sediments before cool down


The dikes of the Piha Beach are still surrounded by sediment. Magma crossed the sedimentary strata to reach the surface and is cools forming these chimneys within the sediments. The sedimentary composition is also very interesting because it contains conglomerates.

Dyke piha
Dyke in red with sedimentary conglomerates around



Conglomerates are derived from the accumulation of sediment of different sizes, ranging from the (sand) micrometer to centimeter (Pebble, Pebble). These conglomerates have specificity to be arranged in layers ranging from large sediment (height in cm) in sediments of a small size (sand).

Sediment conglomerates. We see an evolution in size from large to small. Then from small to large, which mark the boundaries of a layer.


These layers are based on a variation of the intensity of the current. Indeed, when the current is strong, the rocks with a large size will move and settle. Then, when the intensity of the current will decrease, large rocks, will no longer be able to move. Only the smaller rocks will be able to move around by the force of the current and settle.

So these sediments are indicators of the intensity of the current geological periods.

After the deposit of sediments to small size at the bottom, it is possible that it is again an increase in the intensity of the current. At that moment, new sediment to large size will arise on sediments in small size. The filing marks the limit of a geological stratigraphy.

For all definitions: go to this page.
For the time scale is here!


Cette publication a un commentaire

Laisser un commentaire

Ce site utilise Akismet pour réduire les indésirables. En savoir plus sur comment les données de vos commentaires sont utilisées.