Loess (wind-blown silt from the mountains) was deposited 9000-11,000 years ago. This was when the Canterbury Plains were covered in glaciers, and the  last ice-age began disappearing.

As the glaciers retreated, they left behind a layer of gravel and sand. Strong winds blowing across the plains, picked up the fine sediment and deposited it on the lee side of hills and mountains, forming the loess cliffs.

The amateur Timaru geographer John Hardcastle realised in the 1890s that the loess cliffs of Timaru were like a time-line of past climates. He wrote a scientific paper about it. This  became an important document world wide and is still used, to better understand our changing  climate. This information could also help develop models to predict future climate change.

The characteristics of the loess layers, such as thickness, grain size, and mineral content, can provide information about past wind and climate conditions.

The loess is over 20 meters thick in some places and is one of the thickest and most extensive deposits of its kind in the world.

The loess is found all over Timaru and was used for making bricks for Timaru’s construction.

Loess layers at Dashing Rocks - South Canterbury Drone Photography

Loess layers at Benvenue Cliffs - South Canterbury Drone Photography