Today, we continue with some more of Tim’s photographs.
The three rather unprepossessing photographs of greenery we are sharing today actually show the only place in London where the conditions are right, that is wet all year, for sphagnum moss, horsetail, and water pepper to survive. It is a fenced-in gully in the West Meadow on the Kenwood Estate on Hampstead Heath.
Like the many muddy patches and springs in the area, this gully lies part way down a slope where porous sandy soil above gives way to virtually impermeable clay below, so that water seeping downwards underground will suddenly find it has to run horizontally, surface, and may then cause / be trapped in a depression like this.
This clay dominates the geology of the whole of the London area and much of the southeast of England. Many London buildings are constructed of London clay bricks with their yellow-brown colouring, although many of these buildings also have red brick street frontages, as can be seen in the other photograph we are sharing. This is probably a prestige issue, as these red bricks will not have been produced as locally and therefore were probably more expensive.