Fossil Cities

[Image: Art by Joe Alterio; view larger].

I’m thrilled to announce that BLDGBLOG and Wired Science have teamed up with Swissnex to host a live interview—free and open to the public—with University of Leicester geologist Jan Zalasiewicz, author of The Earth After Us: What Legacy Will Humans Leave in the Rocks?, from Oxford University Press.

The event will be from 7-9pm on Wednesday, December 17th, at Swissnex, 730 Montgomery Street, in San Francisco; here’s a map.

Zalasiewicz’s book offers a fascinating and sustained look at what will happen to the material artifacts of human civilization 100 million years from now, when cities like Manhattan are mere trace fossils in flooded submarinescapes, Amsterdam is an indecipherably fragmentary presence in the lithified mudflats of a new, future continent, and cities like Los Angeles and Zurich have been eroded away entirely by a hundred million years of rockslides and weather.

To quote an early chapter from Zalasiewicz’s book at length:

The surface of the Earth is no place to preserve deep history. This is in spite of – and in large part because of – the many events that have taken place on it. The surface of the future Earth, one hundred million years now, will not have preserved evidence of contemporary human activity. One can be quite categorical about this. Whatever arrangement of oceans and continents, or whatever state of cool or warmth will exist then, the Earth’s surface will have been wiped clean of human traces.
Thus, one hundred million years from now, nothing will be left of our contemporary human empire at the Earth’s surface. Our planet is too active, its surface too energetic, too abrasive, too corrosive, to allow even (say) the Egyptian Pyramids to exist for even a hundredth of that time. Leave a building carved out of solid diamond – were it even to be as big as the Ritz – exposed to the elements for that long and it would be worn away quite inexorably.
So there will be no corroded cities amid the jungle that will, then, cover most of the land surface, no skyscraper remains akin to some future Angkor Wat for future archaeologists to pore over. Structures such as those might survive at the surface for thousands of years, but not for many millions.

The book goes on to explore buried cities, flooded cities, and cities destroyed by erosion; the long-term traces of different materials, from concrete and steel to nuclear waste and industrial plastics; and the future magnetic presence of urban metals that have been compressed into the thinnest bands of underground strata. We’ll be talking about cities like New Orleans, London, Hanoi, and Shanghai; New York, Los Angeles, Cairo, and Geneva. What “signals” of their one-time existence will these cities offer in 100 million years’ time? About Mexico City, Zalasiewicz writes:

Mexico City has a good short-term chance of fossilization, being built on a former lake basin next to active, ash-generating volcanoes; but its long-term chances are poor, as that basin lies on a high plateau, some two kilometers above sea level. The only ultimate traces of the fine buildings of [Mexico City] will be as eroded sand- and mud-sized particles of brick or concrete, washed by rivers into the distant sea.

With visions of cities become not spectacular, vine-covered ruins but but vast deltaic fans of multi-colored sand, the book looks at the future geological destinies of everything from plastic cups to clothes.

Alexis Madrigal, from Wired Science, and I will also have five copies of Zalasiewicz’s book to give away to attendees, and there will be drinks and light food after the event, so it will be well worth coming out.

If you get a chance, please RSVP at the Swissnex site, so that they can keep track of expected visitors.

(With special thanks to Joe Alterio for the artwork!)


“Tropical Green” runs 9-10 February 2006, down in sunny Miami: “The two-day Tropical Green conference will be an invaluable experience for architects, interior designers, developers, city planners, politicians, and voters in search of learning the ways of 21st century design that will both help the environment and their wallets.” Check it out.

It’s funny, meanwhile, but I’m reading The Drowned World by J.G. Ballard, even as I post this, and his descriptions – written in 1962 – of a flooded, neo-tropical London have totally changed my conception of what “a tropical city” actually is.

In Ballard’s novel the sun has developed a kind of astrophysical Tourette’s Syndrome, and it’s started scorching the planet with radiation storms and UV bursts. This has melted the icecaps, raised the ambient global temperature to 120º+ and forced everyone to move to northern Canada and Siberia.

London has become a kind of backed-up toilet of silt and Jurassic vegetation, “a nightmare world of competing organic forms returning rapidly to their Paleozoic past.” Huge iguanas lumber around in the heat. Buildings left and right are collapsing, their lower six floors immersed in polluted seawater, “miasmic vegetation… crowding from rooftop to rooftop.”

The city is fossilizing.

As Ballard writes: “A few fortified cities defied the rising water-levels and the encroaching jungles, building elaborate sea-walls around their perimeters, but one by one these were breached. Only within the former Arctic and Antarctic Circles was life tolerable.”

[Image: The Drowned World‘s rather unimpressive cover…].

So the story goes that a research biologist is touring this neo-tropical London, boating from hotel to hotel across fetid lagoons, recording the types of plants that infest the city. Meanwhile monsoons are coming up from the south, everyone is dying of skin cancer and no one can sleep. The intensity of the sun’s radiation is making everything mutate.

In between some eyebrow-raising moments of bad pop-Nietzschean pseudo-philosophy – the surviving humans find themselves psychologically regressing down the totem pole of evolution toward… something or other; it’s all very psychedelic and 2001 – there are some cool descriptions of these new urban tropics:

“Giant groves of gymnosperms stretched in dense clumps along the rooftops of the submerged buildings, smothering the white rectangular outlines… Narrow creeks, the canopies overhead turning them into green-lit tunnels, wound away from the larger lagoons, eventually joining the six hundred-yard-wide channels which broadened outwards toward the former suburbs of the city. Everywhere the silt encroached, shoring itself in huge banks against a railway viaduct or crescent of offices, oozing through a submerged arcade… Many of the smaller lakes were now filled in by the silt, yellow discs of fungus-covered sludge from which a profuse tangle of competing plant forms emerged, walled gardens in an insane Eden.

Anyway, one could analyze the metaphors and all that – Ballard uses the word “competing” twice in the examples above (is he projecting a neo-Hobbesean vision onto Nature…? etc.) – but one could also find something better to do.

And, of course, one could also attend the sustainable design for tropical cities conference in Miami – and tell them you heard about it on BLDGBLOG…

Urban Fossil Value

[Image: J.M. Gandy, speculations toward the ruins of John Soane’s Bank of England – but, again, how about speculations toward the Bank of England’s fossils…?]

As Hurricane Rita carves away at the Gulf shore, Galveston burns, buses explode outside Houston, and New Orleans refloods through badly built and incompletely repaired levees, I stumbled upon an old article, from 1998, about fossilized cities.

Millions of years from now, in geographical regions “entombed by tectonic disturbances,” entire cities – “the abandoned foundations, subways, roads and pipelines of our ever more extensive urban stratum” – will actually come to form “future trace fossils.”

These “future trace fossils,” the article says, form easily preserved systems that are “a lot more robust than [fossils] of the dinosaurs. They include roads, houses and foundations.”

And yet, for all that, only those cities “that were rapidly buried by floods or sandstorms” will be “preserved for posterity.”

Los Angeles, for instance, “is on an upward trajectory, pushed by pressure from the adjacent San Andreas Fault system, and is doomed to be eroded away entirely.” But if a city is flooded, buried in sand, or otherwise absorbed downward, “the stage is set to produce ideal pickling jars for cities. The urban strata of Amsterdam, New Orleans, Cairo and Venice could be buried wholesale – providing, that is, they can get over one more hurdle: the destructive power of the sea.”

It is often remarked in architectural circles how megalomaniacal Nazi architect Albert Speer came up with his so-called theory of ruin value, in which he proposed a new Romano-Fascist Berlin designed to look good as a ruin in thousands of years.

But that’s boring – let’s talk about cities fossilizing over millions of years.

Urban fossil value.

The already buried, subterranean undersides of our Tube-hollowed, war-bunkered modern cities “will be hard to obliterate. They will be altered, to be sure, and it is fascinating to speculate about what will happen to our very own addition to nature’s store of rocks and minerals, given a hundred million years, a little heat, some pressure (the weight of a kilometre or two of overlying sediment) and the catalytic, corrosive effect of the underground fluids in which all of these structures will be bathed.”

Who knew, for instance, that plastics, “which are made of long chains of subunits, might behave like some of the long-chain organic molecules in fossil plant twigs and branches, or the collagen in the fossilized skeletons of some marine invertebrates”? Who knew, in other words, that plastics will fossilize?

Indeed, “with a favourable concatenation of tectonics and sea level, our species could leave behind in a geological instant a much more striking record than the dinosaurs left in a hundred million years.”