The Norber erratics have the peculiar feature that they are older than the rock on which they now rest.
They are Silurian greywacke sandstones of the Ordovician Age and are 430 million years old.
During the last Ice Age 13,000 years ago, the glacier flowed south out of Crummackdale and over the brow of the hill
picking up the Silurain greywacke and transporting it southwards about a mile. When the ice melted, the transported material
was deposited on top of the carboniferous limestone, formed some 330 million years ago on the floor of a shallow sea.
Whilst the general surface of the limestone bedrock has been lowered by about 24" the erratics have been left standing on
small plinths of protected limestone, having acted as natural umbrellas, sheltering the limestone from weathering and erosion.
the main field of them are where the foot paths meet above Nappa Scars which are above the village of Austwick
near Clapham North Yorkshire
Looking at Nappa scars from the "C" in Crummack lane on the map. You can see some of the Erratics on the skyline
It is easy to tell them apart from the clear difference in colour. The sandstone is covered in green lichen and the limestone in white lichen.
If the Glacier didn't leave them perched it left them in a heap
It was a keen wind but managed to shelter behind a boulder for a brew and a homemade bread Sild T/sauce sandwich
Stoves a British army petrol running on Panel Wipe and it's self pressureising i.e. no pumping chefs torch again to light.
Stove closed
Before heading back down.The barn is between New Close Plantation and the "o" in Robin Proctor Scar on the map
cheers all Danny
They are Silurian greywacke sandstones of the Ordovician Age and are 430 million years old.
During the last Ice Age 13,000 years ago, the glacier flowed south out of Crummackdale and over the brow of the hill
picking up the Silurain greywacke and transporting it southwards about a mile. When the ice melted, the transported material
was deposited on top of the carboniferous limestone, formed some 330 million years ago on the floor of a shallow sea.
Whilst the general surface of the limestone bedrock has been lowered by about 24" the erratics have been left standing on
small plinths of protected limestone, having acted as natural umbrellas, sheltering the limestone from weathering and erosion.
the main field of them are where the foot paths meet above Nappa Scars which are above the village of Austwick
near Clapham North Yorkshire
Looking at Nappa scars from the "C" in Crummack lane on the map. You can see some of the Erratics on the skyline
It is easy to tell them apart from the clear difference in colour. The sandstone is covered in green lichen and the limestone in white lichen.
If the Glacier didn't leave them perched it left them in a heap
It was a keen wind but managed to shelter behind a boulder for a brew and a homemade bread Sild T/sauce sandwich
Stoves a British army petrol running on Panel Wipe and it's self pressureising i.e. no pumping chefs torch again to light.
Stove closed
Before heading back down.The barn is between New Close Plantation and the "o" in Robin Proctor Scar on the map
cheers all Danny
