Geology Site Account

Historical site only

In 1882 work commenced on the new docks at Tilbury which was intended to compete directly with the new Royal Victoria and Albert Docks upriver in London. However, no major engineering work had been carried out in this area before and soon there were problems excavating the layers of soft clay and peat resulting in severe delays and additional costs. The excavations were of great interest to geologists and on 17 May 1884 T.V. Holmes of the Essex Field Club (see box) led a combined Essex Field Club/Geologists Association visit to the site which was attended by over 100 members. During the day a description was given of the discovery, the previous autumn, of a human skeleton at the base of a layer of peat at a depth of 11 metres (34 feet). The bones were examined by Sir Richard Owen, Victorian Englands most influential geologist and zoologist, who pronounced them to be Palaeolithic in age and therefore at least 10,000 years old. This view was challenged by Holmes who correctly estimated that the Tilbury Man, as it became known, was of Neolithic age and therefore not likely to be more than 5,000 years old.

Boreholes have since revealed that a total of five layers of peat exist at Tilbury, each one followed by a layer of alluvial clay. The basal peat, which lies on gravel from the buried channel of Thames (see above), has been radiocarbon dated to about 8,300 years ago, a time when sea level was low, Britain was still connected to the continent and the Thames estuary was covered by oak and hazel woodland. Rapid sea level rise followed (as much as 13 millimetres (half an inch) per year) until 7,000 years ago when there was a temporary halt in sea level rise, allowing plants to again take hold and this is marked by a second bed of peat. These cycles have continued to the present day although the eastward dip of the beds suggest that some sea level rise results from an eastwards tilting of southern Britain during this time. Sea level is currently rising at about 2 to 3 millimetres per year in the Thames estuary.