Archaeological Formation

People have done work on the ways in which nature reclaims cities over time. Laura Spinney's 1996 article for New Scientist (Return to Paradise) asks how long it would take "before abandoned London turned back to a rural paradise." Schiffer emphasised how hostile the urban environment is to encroaching flora and fauna with their large areas of "brick, concrete and asphalt." Spinney, on the other hand, points out that in the longer term, the process can take hold in as little as five years. Although many plants would appear in cracks in the sidewalk, or in the pointing of walls, there are more aggressive plants such as buddleia do have roots that can break through mortar and even bricks to reach water. A thin layer of topsoil would result from plants such as these and mosses and lichens.

By the end of the first five years, weeds and clover would cover a city's open spaces. After 150 years of abandonment, oak trees would be well established. The city's buildings would face dangers other than simply being torn apart by flora. Fires would be an increasing risk to the buildings during the summers, as the sun dried out the plants and leaf litter as they collected around them. Meanwhile, the water table would rise again (as the city's populace was no longer tapping it) and lead to problems such as rising damp. The river Thames, with flood controls and reclaimed land no longer maintained, would eventually return to its original shape - shallower and broader. By the end of five hundred years in Spinney's article, relatively little remains of the modern city with its deceptively fragile modern construction materials.