ANCIENT CIVILISATIONS EMERGED ON TECTONIC PLATE FAULTLINES

Welcome to Cosmographia — a newsletter uncovering the deep roots of a turbulent world. For the full map of posts, see here.

This week we’re going to get stuck into the topic of how plate tectonics shaped the emergence of ancient civilisations, and how it still affects the geopolitics of today.

Some two thousand kilometres south of Cairo, among the highlands of Ethiopia, the earth is tearing itself asunder. Far beneath the Afar Triangle a great plume of molten rock rises from the mantle, causing the earth’s crust to buckle and crack, splitting Africa along a seam that runs from Syria to Mozambique. The Great Rift Valley, as this cleft is known, has been forming slowly over the last twenty-five million years. The mountains it has raised catch the summer monsoon rains as they sweep westwards from the Indian Ocean; the waters pour down their eastern flank into the tributaries of a mighty torrent, the Blue Nile, which carries the water and silt north across thousands of miles of desert until its yawning delta disgorges into the Mediterranean. The fertile plains that line the upper reaches of the river gave birth to Egypt, one of the great civilisational centres of the world. Every year, as if attuned to a great cosmic clock, the river burst its banks and a new layer of water and silt would spread over the Egyptian soil, turning it black and fertile. Without that flood there’d have been no Egypt. Without the Ethiopian highlands, there’d have been no flood. The Great Sphinx, implacable and mute, raises its dreaded head because of the movements of the earth’s crust some thirty miles beneath its feet.

The story is similar the world over.

Ancient civilisations all arose near or on top of tectonic faultlines. Map by M. E. Rothwell. CC BY 4.0.

If we take a map of the world’s tectonic plates, and then superimpose upon that a map of ancient civilisations, something remarkable becomes evident. Each of the world’s earliest urban centres appeared along or very near the boundaries between the plates of the Earth’s crust.

Mesopotamia and Persia sit astride the Arabian-Eurasian collision. The Indus Valley and the Gangetic plain were forged by the same earth-shattering impact that raised the Himalayas. The Yellow and Yangtze basins, both cradles of the earliest Chinese civilisation, were shaped by the ancient suturing of the South China block to the Eurasian plate. Phoenicia and Carthage cling to coastlines compressed by the African-Eurasian convergence. Greece and Rome rose on subduction-driven volcanism. The Olmec emerged on the Cocos subduction zone while the Norte Chico and the cultures that followed them were lifted into being by the Nazca plate plunging beneath South America.

Given the vast swathes of land that in theory ancient cultures could have emerged upon instead, this correlation seems to suggest more than mere coincidence. We know that to live atop a tectonic boundary is to run the risk of earthquakes, tsunamis, and volcanic eruptions, but it seems there must have been something about these faultlines that brought great benefits too. Indeed, given their proximity to all the major cradles of ancient civilisation, it seems they may have even been necessary for the independent invention of agriculture, urbanisation, and the development of complex societies. As Lewis Dartnell put it, civilisation is a child of plate tectonics.¹

But what, you may be asking, is the precise mechanism at work here? That is what we’ll explore in the next post: the tectonic origins of civilisation, and how the four types of plate boundary influenced the nature of the civilisations that arose along their faultlines.

But the story does not end with antiquity. The same forces that created civilisation in the first place still shape the world we live in today. For the past century, the geopolitics of the modern age has been a story of hydrocarbons; the rich deposits of the Persian Gulf, Gulf of Mexico, the North Sea, and the West Siberian basin, which have so keenly shaped modern history, exist because of tectonic movements millions of years old. But as the world electrifies, a new tectonic paradigm is emerging. Lithium concentrated in the closed basins of the Andes, cobalt mineralised along the Albertine Rift, rare earths locked into ancient Chinese cratons — the materials of the coming century, just like oil and gas, are not evenly distributed. We will explore how plate tectonics will shape the coming Great Power competition in a third post.

The pharaohs knew not the source of the floods that built their power and their kingdom. The Minoan kings of Crete knew not why the earth shook beneath their feet. But if we can better know the geology of our earth, we can better understand the forces that will shape the next century.²

1. I first came across this idea in Dartnell’s book, Origins, and even wrote about it once before during our series on Uruk. But aside from the poor quality illustration in my paperback edition, I’ve never come across a map that actually shows this relationship, despite an extensive search. Hence the reason for making my own, which you’re free to use. (Like all the original maps I’ve made, and will make, for Cosmographia, I’ve released it under Creative Commons 4.0.)

2. FYI, this week and next, I’m trialing this new weekly schedule:

• Post 1: an introduction to a geohistory concept with an original map (free to read)

• Post 2: a deeper exploration of that concept (paid)

• Post 3: an essay connecting the concept to the modern day (paid)