The large Crossrail portal structures in east London give us a unique insight into the past. They reveal secrets of the deeply buried prehistoric and early medieval landscapes that have been progressively lost below flood deposits of silt sand and clay layers over 10,000 years.
We can use geo-archaeology to learn more about how the landscape appeared, how the Ancient River channels changed over time and how early humans adapted and exploited their environment.
Information: Geo-archeaology is a specialist discipline combining archaeological investigation with studies into the natural processes of geology, plant and animal studies, hydrology, and climate and sea level change.
At Plumstead portal we found tantalising fragments of life in the Bronze Age. Several wooden stakes and a stone hammer tool showed that ancient Britons were accessing and exploiting the landscape resources of the floodplain. The timbers had been shaped into points by early metal axes; some timbers were found in situ pushed into the clay.
Similar timbers we know were used by Bronze Age people to provide an extensive access network of raised wooden walkways across the Thames marshes. These provided an innovative transport infrastructure to allow a quick and efficient way for hunting parties to gather the rich animal and plant life.
At North Woolwich portal, ground models produced from borehole logs show that several islands existed in the distant past. Excavation revealed early hunting parties camped on the higher ground islands, perhaps only overnight. A camp fire was discovered, and several scatters of flint tool-making debris, dating to the Mesolithic Period (6000-10,000 years ago).