When places where people once lived are deserted,
they become overgrown.
Eventually they are buried.
What is underneath the soil
can affect how the crops above them grow.
Ditches dug into the ground fill up with soil over time.
Crops grow well in these place.
They grow higher and look greener.
These create ‘positive’ cropmarks.
Where there are walls, floors or foundations underneath,
there is a thinner layer of soil.
Crops don’t grow as well on top of this rubble.
This creates ‘negative’ cropmarks.
Positive and negative cropmarks can be seen best from the air.
Please note this is not a photo of Rathdown
and is only here to show ‘cropmarks’ in the landscape.
Click on this LINK to read more about cropmarks.
Photographs of cropmarks taken from the air, in 1970
show that there was early settlement at Rathdown, to the North of Greystones.
You can read more about those photographs HERE
Click HERE to see for a project in which
you can create your own cropmarks.
UPDATED to add: During the drought of Summer 2018
something very exciting happened.
The drought caused some cropmarks
which hadn’t been seen before
to become noticeable.
This happened near Newgrange in County Meath.
You can read about this HERE
The same thing is happening in the United Kingdom.
Look HERE to see what is happening in Wales
and HERE for more information and a good explanation
of how cropmarks are made.