Essex Field Club Exhibition
The Essex Birdwatching Society stand had examples of recent annual Essex Bird Reports and
their biannual magazine, Essex Birding. Their programme was also available. On a more down-to-
earth level, Jonathan Cranfield and David Scott had an exhibition illustrating different aspects
of reptile ecology, survey techniques and other issues focusing particularly on the Slow-worm
Anguis fragilis and the Adder Vipera berus. Alf Gudgion presented photographs of mammals
caught in his Longworth traps and showed how to make a cheap, efficient multicatch trap for small
mammals.
Geology was represented firstly by Mark Hanson, with a display of rocks exposed during cable-
laying operations at Hylands Park, Chelmsford, in November 2002. The collection included both
local and distant (exotic) material. The rocks local to south-east England were a glacially striated
chalk boulder and a phosphatic nodule (probably from the Gault of Kent or Surrey). Flint was
abundant at the site but was not displayed. The exotic material included a weathered dolerite
(probably from Northumberland), a micro-granite, again ice-scratched, Lydian stone (veined
tourmaline, probably originally from southwest England, but with a complex history) and vein-
quartz (metaquartzite). Graham Ward had helped in the preparation and identification of the
specimens. Graham Ward put on a display of boulders of various igneous rocks collected from
till (boulder clay) exposed in cuttings made for the Mil and M25 motorways in Essex between
1973 and 1982. Peter Allen provided a display based on a paper published during the year in
Quaternary Science Reviews which firmly established that an additional warm stage/interglacial
occurred approximately 300,000 years ago, based on evidence from south Essex. The existence of
this interglacial had been strongly hinted at by Andrew Snelling in the Essex Naturalist in 1975.
The type site is at Greenlands Quarry, Purfleet, though some evidence came also from three adjacent
quarries. Fossils from at least 48 different vertebrates, including a first record in Britain of macaque
Essex Naturalist (New Series) 20 (2003) 7