A Geology of London for Tunnellers and Engineers

This short paper attempts to set down in non-technical language why some of the major strata units encountered by Crossrail are the way they are. The paper covers the Thanet Sand Formation, the Lambeth Group (the Woolwich, Reading and Upnor Formations), the Harwich Formation and the London Clay Formation.

Space constraints mean this story starts after the deposition of the underlying Chalk. The detailed geographic coverage of the paper is limited to London but the story encompasses diverse events taking place many hundreds of kilometres away.

In addition the paper briefly discusses the formation of the many Terraces created by the River Thames during the ice age. Feint echoes of processes set in train during these cold spells persist to this day and these are continuing to produce measurable ground movements.