Pancake Rocks, Punakaiki

The Pancake Rocks at Punakaiki, on the West Coast of New Zealand's South Island, are heavily eroded limestone formations composed of the Dolomite Point Formation, laid down some 30 million years ago from alternating layers of marine limestone and softer mudstone deposited on the seafloor at different rates. The alternating hard and soft layers, likely reflecting cyclical changes in sediment supply and pressure-driven dissolution during burial, gave the rock a distinctive thin, stacked appearance resembling a pile of pancakes, which subsequent tectonic uplift and coastal wave erosion has exposed and carved into vertical cliffs riddled with blowholes and surge pools. During high seas and incoming tides, water forced through the eroded caverns beneath the rock erupts through several blowholes, a dramatic surface expression of the erosional processes still shaping the formation today.