How were the south downs formed?

The South Downs were formed during the Late Cretaceous period, around 70 million years ago, through the deposition of chalk sediments on the sea floor. Over time, tectonic activity and the uplift of the Earth's crust raised these sediments above sea level. Erosion and glacial action shaped the landscape into the rolling hills and valleys we see today. This geological process has resulted in the distinctive chalk hills characteristic of the South Downs National Park.