Two china clay companies are to receive prestigious environmental awards for giving up quarrying rights on some of the most beautiful areas of Dartmoor.

Clay companies Imerys - formerly English China Clay - and Watts Blake Bearne (WBB) had rights to quarry 400 acres of Shaugh Moor and the Blackabrook valley, one of the most popular parts of Dartmoor.

The rights, granted in 1951, were worth tens of millions of pounds because of the rarity and quality of the unique china clay deposits there.

But two years ago, the companies gave them up, without claiming compensation.

White heaps

Dartmoor National Park Authority is to award them the prestigious Edward Moorshead award for "significant contributions" to Dartmoor.

Imerys said it was a recognition of their sensitivity to environmental issues.

The army continues to use vast areas of Dartmoor

But the Dartmoor Preservation Association, who led a campaign against the quarrying, said the firms had had little choice.

An independent study into quarrying in the area had concluded that was no way they could quarry the area, which includes Bronze Age settlements, in an environmentally friendly manner.

The china clay industry on Dartmoor continues to attract controversy elsewhere.

At Lee Moor on south Dartmoor, extraction by open-cast mining leaves unsightly white heaps of waste.

Granite and limestone is also quarried on Dartmoor.

Other pressures on Dartmoor include the military who won a controversial extension for training earlier this month.

The Army carries out training, in the north of Dartmoor, covering an area of 30,000 acres and in the south, covering 2,000 acres.