Hull Geological Society
Common urban rocks -
(a work in progress)
Chalk is a white, very fine grained limestone that was deposited in the Late Cretaceous. It is the rock that forms the Yorkshire and Lincolnshire Wolds.
I love the Chalk and study its fossils and geological history, but it is normally a RUBBISH building stone. Although the Yorkshire Chalk is stronger that the Chalk of southern England it is still porous. It soaks up water and when the weather gets cold the water in the rock can freeze; when the water freezes it expands and can shatter the chalk.
However, there seems to be a belt running east-west across the northern part of the Yorkshire Wolds where the Chalk has been squeezed and toughened by faulting and folding, which makes it more suitable for use in buildings. You can see chalk being used for buildings in Flamborough village, Flamborough Head, Speeton, Foxholes and Langtoft.
Copyright - Mike Horne and Hull Geological Society 2020
Registered Educational Charity No. 229147