The Demise of Mesopotamian Empires

Mesopotamia, in the Middle East, is known as the birthplace of civilization. Two of its early civilizations mysteriously collapsed, which baffled researchers until they found the reason—in stalagmites.

Around 10,000 years ago, hunter-gatherers there developed agriculture and domesticated animals. Abundant food and animal labor allowed them time to invent: the wheel, glassmaking, and eventually writing.

This set the stage for the world’s first empires: the Akkadians then the Neo-Assyrians controlled all of Mesopotamia, though a thousand years apart. And both suddenly vanished.

Recently, some geologists went looking for clues in the region’s caves.

Water, dripping from the cave ceiling to the floor, carries minerals from the world above. Over centuries, the minerals solidify to form stalagmites, in layers like tree rings. By carefully analyzing each layer, the geologists discovered the kingdoms’ fates.

When both empires rose and thrived, the stalagmites were growing rapidly—indicating abundant groundwater from years of good rainfall, which brought plentiful crops.

Their collapses coincided with slow stalagmite growth and thin mineral layers high in magnesium—indicating scarce rainfall and frequent dust storms.

Both kingdoms were brought down by centuries-long drought.

In this and other ways, geologists are helping to understand extreme climates of the past.