A detailed gravity survey has been conducted over the Stour buried tunnel-valley between Sturmer and Long Melford in Essex. The resulting Bouguer anomaly map indicates that the density of the boulder clay filling the valley is higher than that of the underlying chalk. The interpretation of the Bouguer anomaly clearly indicates the subsurface position of the Stour buried tunnel-valley and calculations of the depth to the base of the valley fill have been attempted. Detailed resistivity sounding surveys at proposed borehole sites confirmed the gravity interpretation and provided more detailed information on drift lithology and thickness.
- © The Geological Society 1984