Source Rock for the World's Largest Oil Field

December 02, 2012

Qusaiba_Conrad_Allen - Copy2 (2)

Photographer: Conrad Allen
Summary Author: Conrad Allen

As shown above, a shepherd tends to a flock of sheep in a remote and nearly deserted village in Qassim Province, Saudi Arabia. The outcrop in the background is the geologic type section for the Qusaiba Member, which is a primary source rock for the world's largest oil field (Ghawar). The organic-rich shale of the Lower Silurian Qusaiba Member, of the Qalibah Formation, is one of the most prolific source rocks on the planet. It provides more than 90 percent of the Paleozoic light oil and gas accumulations known on the Arabian Peninsula. Photo taken on November 19, 2012.