The Whin Sill or Great Whin Sill is a tabular layer of the igneous rock dolerite in County Durham and Northumberland in the northeast of England. It lies partly in the North Pennines Area of Outstanding Natural Beauty and partly in Northumberland National Park and stretches from Teesdale northwards towards Berwick.
It is one of the key natural features of the North Pennines. A major outcrop is at the High Force waterfall in Teesdale. Bamburgh Castle, Dunstanburgh Castle, Lindisfarne Castle and stretches of Hadrian's Wall all strategically take advantage of high, rocky cliff lines formed by the sill.
The Whin Sill complex is usually divided into three components: Holy Island Sill, Alnwick Sill and the Hadrian's Wall-Pennines Sill, which were created by separate magma flows but about the same time.
The Little Whin Sill is an associated formation to the south in Weardale.
Read more about Whin Sill: Derivation of Name, Geology, Effects On Landscape and Geography
Famous quotes containing the word sill:
“Still grows the vivacious lilac a generation after the door and lintel and the sill are gone, unfolding its sweet-scented flowers each spring, to be plucked by the musing traveller; planted and tended once by children’s hands, in front-yard plots,—now standing by wall-sides in retired pastures, and giving place to new-rising forests;Mthe last of that stirp, sole survivor of that family.”
—Henry David Thoreau (1817–1862)