The Persian Gulf, the hydrocarbon hub of the world. Where did this wealth come from?

The war in the Middle East and the associated blockade of the Strait of Hormuz have painfully highlighted the world’s dependence on Arab fossil fuels. Why is the Persian Gulf so rich in oil and natural gas? The answer lies in complex geological processes that have lasted millions of years.

Optimal extraction conditions

More than half of the world’s oil resources are located in the Middle East. The combined reserves of North and Central America, Africa, and the territory of the former Soviet Union do not even account for 15 percent of global reserves. Meanwhile, five giant fields are located around the Persian Gulf, each containing more than 5 million barrels of valuable fuel.

The strategic importance of the region results not only from the abundance of its deposits, but also from its location, which facilitates extraction. Wells here are far more productive than the best ones in Russia and the North Sea. In terms of abundance and ease of production, there is nothing better than the Persian Gulf region, says Scott L. Montgomery, a geologist from the University of Washington.

The perfect recipe for oil

The Persian Gulf is a relatively young structure, formed as a result of the collision of two tectonic plates, the Arabian and Eurasian, in the Cenozoic era, around 35 million years ago. This geological clash of giants led to the formation of a subsiding foreland basin, which between about 14,000 and 6,000 years ago was flooded with saltwater due to rising sea levels.

On the Iranian side of the Persian Gulf, the Zagros Mountains were uplifted, and their intricately folded structure became an ideal reservoir for accumulating hydrocarbons. It is within these folds that Iran’s fossil fuel wealth is hidden. On the opposite side, on the Arabian Plate, dome structures formed with limestone rocks that easily dissolve, allowing oil and natural gas to migrate. In this way, Qatar’s gas fields and Saudi Arabia’s oil fields were filled.

The scale and intensity of oil and gas formation in the region are the result of another fortunate combination of factors. The rocks here contain at least 2 percent organic material derived from marine zooplankton and phytoplankton, and during the uplift of mountain ranges, a significant portion of this carbon-rich debris became trapped beneath the floor of the Persian Gulf. The conditions of high temperature and pressure proved ideal for transforming hydrocarbons into high-energy fuels.

The Persian Gulf in the grip of a climate curse

The principle of trade-offs perfectly describes the natural conditions of the Middle East. The extremely rich resources of fossil fuels that drive the economy are only one side of the geographical equation. The other is the lack of rivers and exceptionally low precipitation – virtually the entire Arabian Peninsula is desert.

The severe and persistent water deficit in the region has been a source of crisis for decades, one that is escalating under the influence of climate change and a growing population – the Middle East is home to 6 percent of the world’s population, who have access to only 1–2 percent of global freshwater resources. Paradoxically, the fossil fuels that constitute the region’s wealth and main economic driver increase greenhouse gas emissions and further heat the atmosphere.

Unique geological conditions have therefore become both a source of economic prosperity for Saudi Arabia, Qatar, and the United Arab Emirates, and a cause of decades-long struggles with increasing drought and armed competition over climate-unfriendly fuels.