This lecture was presented on 10 December 2008 by Bob Markham, a very long-standing member of The Ipswich Society. Bob's interest in the geology of the local area began as a schoolboy and extended throughout his long career as a professional geologist.
The lecture was illustrated by a series of colour photographs taken by himself mostly during the period 1960 to 1980. These featured mainly a number of sites located throughout the town on which excavations were taking place in building projects. These enabled the geology of the strata exposed to be studied. The materials which occur in this area of Suffolk include sands, crags, chalk and London Clay.
The projects shown included:- the construction of the foundations for the central pillars of the Orwell Bridge; the construction of the Civic Centre underground car park; construction of the Ipswich Port West Terminal; the building of Debenham's store in Lloyds Avenue; and the building of Stoke High School and sports centre.
The effect of springs above layers of impermeable London Clay was illustrated by photographs taken inside the railway tunnel at the railway station showing the very damp conditions.
Coprolite Street is the site of one of the first fertiliser factories in the UK to manufacture superphosphate by the treatment of coprolites with sulphuric acid. Coprolites, which are phosphate nodules, occur in the surrounding area including at Levington and Waldringfield.
Bob was supported by his wife, Caroline, who was responsible for the control of the technology used to project the photographs.