Hull Geological Society
Common urban rocks -
Tilberthwaite Tuff
This is a fine grained green rock from the Lake District. It falls into all three basic rock types of the Rock Cycle. It is made of volcanic ash (Igneous Rock) that fell into water and steeled into layers (Sedimentary Rock) that later was subjected to great pressure and developed a slatey cleavage (Metamorphic Rock). It is used as a decorative facing on some buildings and you might spot cross sections of sand ripples and volcanic bombs.
Copyright - Mike Horne and Hull Geological Society 2020
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