Eridge Rocks

Eridge Rocks,  26 April 2018

This part of the High Weald has quite a few sandstone cliffs and outcrops, something we did not have in the Hayes area where I used to live.  That area was mostly on chalk or gravel.  Eridge Rocks consists of about 600 metres of what you see here, a small but impressive cliff.  You can walk out along the bottom, where these photos were taken from, and back along the top. 

Eridge Rocks,  26 April 2018

Today, the Sussex Wildlife Trust led a walk along the rocks and through the woodland they sit in.  It's a designated Site of Special Scientific Interest for the mosses, liverworts, ferns and lichens that grow on the rocks.  Climbers come here too, and you can see their chalk on some of the drier rocks.

I expect it counts as a cheat if you go up that dead tree.

Eridge Rocks,  showing the erosion patterns.  26 April 2018

Erosion has produced cracks in two directions, and a lot of unusual honeycomb patterns on the surface. 

The Victorians loved this place and apparently were known to have dined out here in luxury at least once.  The people who care for the rocks have had to remove a lot of Rhododendron (the Victorians loved Rhododendrons) and now they try to keep the damper rock faces in dappled shade.  This lets the mosses, etc get some light without being shaded out or burnt dry. 

The surrounding woods are full of bluebells.

Woods by Eridge Rocks, 26 April 2018.

Not quite fully out yet, but nearly.  I saw a number of other ancient woodland indicator plants too, such as Redcurrant and

Yellow Pimpernel, Lysimachia nemorum.  Woods near  Eridge Rocks, 26 April 2018.

Yellow Pimpernel, which likes to grow beside paths.

We saw quite a few beeflies, some hoverflies, bumble bees and a couple of butterflies. 

Beefly, Bombylius major.  Woods near  Eridge Rocks, 26 April 2018.

Interesting woods - I'll be back.

Woods by Eridge Rocks, 26 April 2018.

Riddlesdown Quarry

Riddlesdown Quarry from within the security fence, 2 July 2011.

It's not one of my local commons, but it was recommended, so I booked for the summer flower and butterfly walk to Riddlesdown Quarry on July 2nd. It's a City of London common like West Wickham Common and Spring Park, which I visit often as they are within walking distance of my house, but I had never been to Riddlesdown before. The warden there is Matt Johnson, and he led the walk with the assistance of one Frances, a local volunteer, who knew the quarry and its flora in detail.

Both the common and the quarry are spectacular. First, a long straight path through open grassland, thought to be on the route of a Roman road. Excavation is needed to confirm this. Grassland, and some trees and scrub off to the sides; the common is being actively managed to increase the open grassland. The wildflowers were profuse. I saw several which were new to me, or if I had seen them before I didn't know at the time what they were. Vervain, Dropwort, Tufted Vetch, Rest Harrow. Spear Thistle and Welted Thistle. The Mignonette looked very much like the garden plant of the same name that I remember from my childhood.

Long-headed poppy, Papaver dubium subspecies dubium,
in Riddlesdown Quarry. 2 July 2011.

Some plants that I did know grew here in great numbers. We followed a track that verged away from the Roman road and saw hundreds of Pyramidal Orchids, by the path and under a tree. Then we walked up a slope and came to the top of the quarry.

The common is open to all, but the quarry is surrounded by a tall metal security fence, and there are two locked gates to get through before reaching the edge of the excavation. It is a spectacular sight. Geologists would love it. Until 1996 it belonged to Blue Circle, a company that sold cement, but they had not taken chalk for some while before that.

There were a few butterflies around on the grass plateau outside, but when we went in we were suddenly surrounded by them; Meadow Browns, Ringlets, Marbled Whites and some Skippers, fluttering around, disturbed by our passing. And there were more plants, different again. Some were vivid, with strong colours, like the Everlasting Pea and the Long-Headed Poppy; others had clear pastel shades like Centaury and Restharrow.

Kidney Vetch, the food of the caterpillar of the scarce Small Blue butterfly, was all around, but we did not see the butterfly, though it is known to live here. Hop Trefoil, Eyebright, Rosebay Willowherb, many plants with beautiful and evocative names. And I discovered from one of the walkers that Bird's-Foot Trefoil, sometimes called eggs-and-bacon here, is called "old women's teeth" in Sweden.

Hop trefoil, Trifolium campestre, in Riddlesdown Quarry. 2 July 2011.

I thought I might see some of the day-flying Burnet moths, as those teeth are what the caterpillars eat. But no, though there are said to be plenty of them. I did see a Cinnabar, another brightly coloured day-flier, whose caterpillars eat only Ragwort. One of the group pointed out a Peregrine Falcon, rather larger but a lot further away, circling around the trees at the top of the quarry.

The path winds down into the centre of the quarry, where we looked around for a while, and then back up and home again. The walk was advertised as three hours. We started off at 10 a.m. and got back to the car park at 1:30 p.m. It did not seem a long time. There is only one chance each summer to visit the quarry, and I will definitely book early next year.

This was a good chance to try out my new camera, a Canon EOD 60D, and all the closeup photos were taken with that and my 100mm macro lens. The wide view of the quarry, and the view of the group, were taken with my little Canon Ixus 100. As usual, these photos show only a tiny fraction of the good things there were to be seen.

Matt Johnson addressing the group at the top of Riddlesdown quarry. 2 July 2011.

One of the group remembered when that table was new; it was quite flat then.

Common centaury, Centaureum erythraea, in Riddlesdown Quarry. 2 July 2011.

Cinnabar moth, Tyria jacobaeae, in Riddlesdown Quarry. 2 July 2011.

Round-leaved wintergreen, Pyrola rotundifolia, in Riddlesdown Quarry. 2 July 2011.

Wolf spider hunting under the grass, carrying her young on her back, in the meadow above Riddlesdown quarry.
2 July 2011.

These spiders are quick-moving hunters and they don't hang around and pose for the camera. I have seen lots of wolf spiders this summer, but I have very few photos.

Marmalade hoverfly, Episyrphus balteatus, on a small scabious, Scabiosa columbaria,
on Riddlesdown Common.  2 July 2011.

Geology at High Elms

Paul Rainey crumbling a piece of Seaford Chalk

Wherever I have lived, if there has been a garden the soil has seemed mostly to consist of clay. I had a vague image of the earth as consisting of rock, with clay on top. Even though I knew quite well that there were many other sorts of environment, in practice it always came back to clay.

Much of my current locality is chalk or gravel. How does this affect my current garden? Not at all, because the house was built on an old railway yard, and if I dig down a foot through the clay I find coke.

On Sunday there was a geology walk around High Elms Country Park and its immediate neighbourhood towards Farnborough, led by Paul Rainey of the Ravensbourne Geological Society. This area is almost all on chalk. You can see chalk very close to the surface; nearby, I have seen it turfed out of a badger's sett, and here it can be seen in road cuttings.

There is another way to see what is near the surface in woodlands in the south of England. All the woods have many trees that were toppled during the Great Storm of 1987, when winds of hurricane strength blew down an estimated 15 million trees. I got that number from Wikipedia, but I remember that night well. When those trees were pushed over, their root balls were tilted up and they brought with them all the attached soil. That soil is still mostly there and gives you a very good idea of what's under the topsoil, without having to dig.

Flint Lodge, the gatehouse to High Elms, showing flint in the walls

The top photo shows Paul Rainey crumbling a piece of chalk from one such root ball. Like all experts, Paul could read more from his surroundings than those less knowledgeable. Chalk, being a rock, albeit a weak one, can support more of a slope than clay or gravel. We were on Seaford chalk, and elsewhere on the estate is a layer of Lewes chalk, which is stronger and supports steeper slopes.

Chalk, of course, is full of flints. The Blackheath gravel layer of the nearby Hayes, Keston and West Wickham commons consists of small black flint pebbles, created where a sea has broken up larger flints and rolled them around. There were many such pebbles on the surface as we walked, which must have come downhill from elsewhere, as there is no gravel layer here.

Flints were a valuable resource in the stone age, and in more recent times they were used to surface walls, for protection or decoration. The area is full of houses and churches that demonstrate this. The second photo shows Flint Lodge, the gatehouse of the High Elms estate, which demonstrates this in name and in fact. The white border around the broken edges shows that these flints were freshly dig for this use. That border is usually weathered off on flints taken from the surface.

A chalk pit in High Elms Country Park

At the top of the slope is a playing field attached to Farnborough Village. Here, there is a layer of Thanet sand. Sand, chalk, flint, gravel .. it's easy to see that this whole area was once a sea-bed.

The various soils and rocks in this area have in the past been used as resources by the locals. The playing fields at Farnborough were once a sand pit. The gravel at Keston Common was a local resource. And here in High Elms Country Park is a chalk pit.

It goes down about 30 feet and branches out into three short excavations. This is where chalk was excavated to put on the fields, though just why the fields weren't already chalky enough I do not know. Chalk was taken from deep down because that nearer the surface was only good for paths and roads, not for the fields. This pit is now a home to bats; I wasn't able to find out what type.

(Added later: I have since heard from Ishpi Blatchey, a local bat expert, who wrote: "The ... dene hole .. is a bat hibernation site - not used in the summer as it is too cold for maternity roosts. Brown long eared, Daubenton's, and Natterer's bats are regularly seen there in winter by licensed bat workers who monitor the site for the National Bat Monitoring Programme." Here is a note of one of Ishpi's bat walks.)

As you can see, it rained during this walk ...

Here are some random images.

Cut ivy stems on a felled treetrunk near High Elms

Ivy can be quite substantial, and can be considered as a workable wood in itself.

Last Autumn's fallen leaves with signs of tar spot fungus

The edge of the field was full of leaves like this.

Weathered gate ball at The Clock House, High Elms

This was one of the decorative balls on the gateposts of The Clock House. I don't think it will last much longer. One good frost should split it apart. In fact, I can't see how it is still holding together.