tracing oil reserves to their tiny origins

NYTimes | In 1913, as the automobile zoomed into American life, The Outing Magazine gave its readers a bit of background on what fueled the new motorcars in “The Story of Gasoline.” After a brief vignette describing the death of “old Colonel Stegosaurus Ugulatus,” the article explained that “yesterday you poured the remains of the dinosaur from a measuring-can — which, let us hope, held five gallons, full measure — into your gasoline tank.”

The idea that oil came from the terrible lizards that children love to learn about endured for many decades. The Sinclair Oil Company featured a dinosaur in its logo and in its advertisements, and outfitted its gas stations with giant replicas that bore long necks and tails. The publicity gave the term “fossil fuels” new resonance.

But the emphasis turned out to be wrong.

Today, a principal tenet of geology is that a vast majority of the world’s oil arose not from lumbering beasts on land but tiny organisms at sea. It holds that blizzards of microscopic life fell into the sunless depths over the ages, producing thick sediments that the planet’s inner heat eventually cooked into oil. It is estimated that 95 percent or more of global oil traces its genesis to the sea.

“It’s the dominant theory,” said David A. Ross, scientist emeritus at the Woods Hole Oceanographic Institution on Cape Cod. The idea, he added, has been verified as geologists have roamed the globe over the decades and repeatedly found that beds of marine sediments are “a good predictor” of where to discover oil.

The theory also explains offshore drilling — why there is oil in many seabeds, why it is more often near shore than in the abyss, and why, despite the Deepwater Horizon disaster in the Gulf of Mexico, which killed 11 crewmen and caused the worst offshore oil spill in American history, oil experts say offshore drilling may increase, rather than cease.