The Pancake Rocks and Blowholes are a coastal rock formation at
Punakaiki
Punakaiki is a small village on the West Coast, New Zealand, West Coast of the South Island of New Zealand. It is located between Westport, New Zealand, Westport and Greymouth on , the only through-road on the West Coast. Punakaiki is immediatel ...
South Island
The South Island ( , 'the waters of Pounamu, Greenstone') is the largest of the three major islands of New Zealand by surface area, the others being the smaller but more populous North Island and Stewart Island. It is bordered to the north by ...
of New Zealand. They are a popular visitor attraction.
Location
The Pancake Rocks and Blowholes are located at Dolomite Point, immediately adjacent to the village of Punakaiki, in an area that is protected and forms part of the
Paparoa National Park
Paparoa National Park is on the west coast of the South Island of New Zealand.
The park was established in 1987 and encompasses . The park ranges from or near the coastline to the peaks of the Paparoa Range. A separate section of the park lie ...
.
Geology
The limestone of the Pancake Rocks has been uplifted and then eroded into the current landforms by a combination of two processes –
karst
Karst () is a topography formed from the dissolution of soluble carbonate rocks such as limestone and Dolomite (rock), dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. Ther ...
erosion (a slow process where chemical erosion of the limestone occurs through the action of water flowing in joints and caverns), and
coastal erosion
Coastal erosion is the loss or displacement of land, or the long-term removal of sediment and rocks along the coastline due to the action of Wind wave, waves, Ocean current, currents, tides, wind-driven water, waterborne ice, or other impacts ...
(including the collapse of caverns).
Limestone formation
The Pancake Rocks are a heavily eroded
limestone
Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...
formation where the sea bursts through several vertical blowholes during incoming swells, particularly at high tide. The limestone was formed in the
Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
period (around 22–30 million years old), a period in the geological history of New Zealand where most of the continent of
Zealandia
Zealandia (pronounced ), also known as (Māori language, Māori) or Tasmantis (from Tasman Sea), is an almost entirely submerged continent, submerged mass of continental crust in Oceania that subsided after breaking away from Gondwana 83 ...
was submerged beneath shallow seas. The limestone rocks of the Punakaiki region began forming on the sea floor in warm coastal waters, offshore from a group of low-lying islands. There was a great profusion and diversity of marine organisms growing in these waters, and when these animals died, their shells settled on the sea floor along with small amounts of sand and mud eroded from nearby islands. Over millions of years, vast quantities of shell debris accumulated on the sea floor, eventually forming a thick deposit of nearly pure
calcium carbonate
Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skel ...
.
About 25 million years ago, at the beginning of the
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
, there was a phase of upward movement of the Earth's crust (known as the Kaikoura Orogeny), that led to the formation of the
Southern Alps
The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) are a mountain range extending along much of the length of New Zealand, New Zealand's South Island, reaching its greatest elevations near the range's western side. The n ...
. Large amounts of sand and mud were eroded from the emerging land and deposited on the sea floor, on top of the shell debris. Over the following 20 million years, as the uplift of the crust continued, the older shell debris became buried under a great thickness of accumulated sand and mud. The high pressures created by the new layers expelled water from the shelly sediment, and this gradually became cemented and
lithified
Lithification (from the Ancient Greek word ''lithos'' meaning 'rock' and the Latin-derived suffix ''-ific'') is the process in which sediments compact under pressure, expel connate fluids, and gradually become solid rock. Essentially, lithificati ...
to form limestone rock. In the
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58stylobedding. Under the influence of high pressure and compaction, small imperfections in the calcium carbonate that forms the limestone tend to aggregate in horizontal planes, in a process known as grain boundary diffusion. This leads to regular bands of stronger rock separated by weaker and more erodable mudstone rock. Thousands of years of rain, wind and spray have mechanically weathered away the surface of the mudstone layers, leaving the limestone layers in relief.
Continuing uplift
Uplift of the crust is continuing and its recent effects can be seen at Dolomite Point. The flat surface of the headland is in fact an old beach surface, formed at sea level 100,000 years ago and since uplifted by around . Patches of beach gravel and sand can be found on the headland.
Blowholes
The blowholes at Dolomite Point, Punakaiki have been formed through combined processes of erosion. The action of waves, combined with karst erosion in joints and faults in the limestone rock, leads to the creation of caverns that become sea caves. When the sea cave erodes upwards and towards the land, it can create an opening to the surface. Incoming waves trap air in the sea cave and the air inside the cave becomes compressed, leading to the ejection of air and water upwards from the top of the blowhole. The activity level of the blowhole depends on factors like tide, sea conditions and the geometry of the caverns. The best conditions for viewing the blowholes are at high tide when there is a large incoming ocean swell.
Tourism
State Highway 6 is the only through-road on the West Coast, and a large number of visitors pass through Punakaiki. In 2017, it was estimated that there were 450,000 visitors, and many of these take the short walk to view the Pancake Rocks and Blowholes. It has been claimed that the Pancake Rocks are the most photographed rock formations in New Zealand.
The site is accessible by a number of walkways winding through the rock formations. Parts of these are
wheelchair
A wheelchair is a mobilized form of chair using two or more wheels, a footrest, and an armrest usually cushioned. It is used when walking is difficult or impossible to do due to illnesses, injury, disabilities, or age-related health conditio ...
-accessible and others are carved into
stairway
A stairwell or stair room is a room in a building where a stair is located, and is used to connect walkways between floors so that one can move in height. Collectively, a set of stairs and a stairwell is referred to as a staircase or stairway. ...
s up and down the rock faces.
File:Punakaiki - looking south.jpg, Looking south from the Pancake Rocks
File:Pancake Rocks Walk Punakaiki.jpg, Walkways around the Pancake Rocks area
File:Pancake Rocks Punakaiki New Zealand Blowhole.jpg, Walkway and blowhole
File:Pancake rocks underwater cave.jpg, Surge pool