Geology of Kent into northern France. The fold arises from the continuing Alpine orogeny and results in the general northward dip of the rock strata in most of Kent. There are extensive spreads of coastal and estuarine alluvium on the Thames Estuary coast, in the low ground surrounding the Isle of Thanet and across Romney Marsh. Alluvium also floors the valleys of the River Medway and Stour. 'Clay-with-flints' is a commonly occurring deposit across the North Downs which is a product of periglacial conditions during the last ice age. Loessic deposists, of aeolian origin i.e. windblown, are common in east Kent, especially on
Mines on the first day of the Somme Bois Français had already taken place in the winter of 1914 and spring of 1915. Before the summer of 1916, no-man's land south of Bois Français had already witnessed the blowing of at least eight mines, and the area of Kiel and Danube trenches, located some to the east of Bois Français, had also seen extensive underground operations. In October 1915, John Norton-Griffiths had even advocated the use of poison gas to deal with the German resistance in the Bois Français sector, but the proposal was not followed up. As at Fricourt, no frontal assault was planned in this area