In the 1960s, English Heritage cut this trench through
the rock. The rock is made up of lots of layers stacked on top of each
other, each layer representing a period of time.
What
is the geological cutting? Listen to Graham Worton 禄
Look closely at the particles in the rock - they become
finer as you walk up through the cutting. Each layer gives geologists
clues - the layers here represent sea levels. Fine particles mean that
the water wasn't very energetic. (If it was rushing in fast currents,
it would carry bigger pebbles and rocks.) So, because the particles change,
the water which covered Dudley millions of years ago changed. So was the
land rising or the sea level dropping? Scientist wanted to find out, so
they cut this trench straight through this limestone hill.
What
was Dudley like millions of years ago? Listen to Graham Worton 禄
 |
Orange stripe shows volcanic activity |
Look out for yellow/orange stripes in the limestone.
These show volcanic activity. When a volcano erupted, it covered the ground
(and sea!) with a layer of volcanic ash and rock. And here it is, sandwiched
in the limestone.
Look out, too, for holes in the rock - they're the burrows
of soft-bodied creatures (like worms). Their bodies rotted away but the
burrows remain.
Since the cutting was made, plants have begun to move
in. They're growing in cracks in the rock (as you can see in the photo,
right). Soil starts to build up and the plants' roots can work their way
through to anchor themselves in the rock.
 |
Gate after The Caves pub |
The bottom of the cutting, you can see the road on the
right which is raised above where you're standing. The 18th century quarrymen
left the limestone under the road - so the road must be older than the
quarries! The trees growing here tell historians exactly when the quarrying
stopped - that's when they started to grow. If you cut down a tree, a
slice across the trunk shows rings of growth which can be used to accurately
calculate the age of the tree.
Walk out at the foot of the cutting onto Wren's Hill
Road. Turn left and go through the gate after The Caves pub (see photo,
above).
View
map of this stage
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