Silent Keepers of Time
Moeraki Boulders, Otago Coast, South Pacific Ocean, South Island, New Zealand.
The Moeraki Boulders are concretions created by the cementation of the Paleocene mudstone of the Moeraki Formation, from which they have been exhumed by coastal erosion. The main body of the boulders started forming in what was then marine mud, near the surface of the Paleocene sea floor. ...The larger boulders, 2 meters (6.6 ft) in diameter, are estimated to have taken 4 to 5.5 million years to grow. A drop in sea level allowed fresh groundwater to flow through the mudstone enclosing them.
Silent Keepers of Time
Moeraki Boulders, Otago Coast, South Pacific Ocean, South Island, New Zealand.
The Moeraki Boulders are concretions created by the cementation of the Paleocene mudstone of the Moeraki Formation, from which they have been exhumed by coastal erosion. The main body of the boulders started forming in what was then marine mud, near the surface of the Paleocene sea floor. ...The larger boulders, 2 meters (6.6 ft) in diameter, are estimated to have taken 4 to 5.5 million years to grow. A drop in sea level allowed fresh groundwater to flow through the mudstone enclosing them.