Ill late June news broke that the EU is going to reform the CAP, which governs how our
farmers get paid. It seems that the message has got home that butter or wheat mountains
and milk lakes are not especially useful, and instead farmers should be paid for more
environmentally gentle farming without such massive overproduction. Details have
not yet been spelled out, but already France has said they wish to withdraw and stay with
the present system.
On Saturday 5"' July nine people collected to explore some areas near Davy Down. We
particularly wanted to look at a section of sloping woodland that is threatened by the
imminent widening of part of the A13, and also the Mardyke riverside and nearby
marshland.
A couple of weeks before our visit, a top geologist had looked at the many sarsen stones
in the belt of woodland. Sarsen stones are not uncommon in Essex, but usually they are
very weathered, whereas the ones here are not. Sarsens are about 20 million years old,
which is not as old as the chalk in the Grays area, but older than most of the other sand
and gravel deposits that are nearby. They were formed as a shallow sea slowly dried up
and the silica-laden water rose up through the sand to the surface, where it evaporated
and left a silica cement binding the sand grains together. So it is a sandstone, but typically
in a layer only about 20 to 60cm thick, which has then been broken in later earth
movements (eg ice movement) making slabs in this area approximately 1 metre square
or so. The shape of the original sand can be deduced from the ripple-like patterns, called
glurps, that adorn one surface.
As we climbed up the slope from the water-meadows to the heights above the cutting of
the Al3 we noted how the vegetation changed from very sparse due to severe overgrazing
on the low meadow, then scrub (where Ken Adams found some interesting hybrid roses)
and some woodland, and then a much barer region on the top of the bank that was
heavily grazed by rabbits. There were lots of large sarsen stones up here, and very
impressive they were! (see plate 1)
A local botanist, Alan Sadgrove, who already knew the area, kindly pointed out the Wild
Liquorice, Viper's-bugloss and Bugloss, and later the Blue Fleabane and Carline Thistle.
There was a lot of Creeping and Hoary Cinquefoil with Heath Speedwell, Common
Centauiy, Field Madder, Thyme-leaved Sandwort, some Wild Basil and one plant of
Oval Sedge. The soil was thin and sandy, overlying the northern limit of the exposed
chalk in this area. There were large numbers of Common Cudweed, and suddenly we
saw among them some of the legally protected Red Data Book rarity Broad-leaved
Cudweed (see plate 2 and inset). All the plants in this area were very short (the sward
was about 3cm high), so it was on to hands and knees to find some more! We found
about 20 plants over an area of about 5 square metres. As we turned to come down to
the woodland we saw Hairy Violet, another chalk indicator. Then we rushed on, as it
was already 2pm and we had not yet got back to the cars for lunch.
Essex Field Club Newsletter No. 42, September 2003 7