Science: The Big, Cool Sea

Geologists, who sometimes attack their work from strange angles, have now been climbing mountains to make a study of undersea rocks. Last week Dr. Norman D. Newell, of New York City’s American Museum of Natural History and Columbia University, was studying fossil seashells he had just brought back from the Peruvian Andes. They told him about the strata (possibly oil-bearing) deep under the Amazon Basin hundreds or thousands of miles away. They also suggested that an ancient ice age once chilled the sea water right across the equator.

The Amazon region is tough to explore on the surface, and almost unknown geologically. But both the Amazon and the towering Andes were covered some 200 million years ago by the same shallow sea. An unexplained disturbance wrinkled the earth’s crust. The western part of the sea bottom was lifted high in the air, where its sedimentary strata lie exposed today. The rest (toward the east) is still deeply buried under the tangled jungle.

Temperate Water. Dr. Newell went to Peru to collect fossils of shellfish that lived and died in the ancient sea. The shells, embedded in the sedimentary rocks, are an accurate key to the age and origin of the strata. He brought back two tons of specimens, grubbed out of Andean rocks by U.S. and Peruvian assistants.

The Amazon sea apparently extended from eastern Brazil to islands on the present site of the Andes. It was not a tropical sea, but temperate, since the animals that lived in it are characteristic of cool water. It must have extended without a break right past the equator and into the region of the present Mississippi Valley. In those .days the same shellfish lived in Peru and in Oklahoma.

Temperate Life. All this was good news for the oil companies. Petroleum is believed to come from the dead bodies of minute animals sinking to the bottom of shallow seas. If the same marine fauna flourished in both the U.S. and South America, there should be good oil prospects in the Amazon Basin as well as in Texas.

Dr. Newell (though glad to encourage his oil-company backers) was more excited about the theoretical aspects of his discovery. Rarely had paleontologists found a marine fauna that was practically identical on both sides of the equator. Obviously, he speculated, there was no tropical belt of warm water in those days to check the spread of temperate sea life. But why?

Dr. Newell did not know for sure, but he could make some guesses. Perhaps the ice age which chilled the earth in those remote days eliminated all climatic zones except the frigid and the temperate. Perhaps the earth’s poles were in different places then, allowing a temperate zone to curve unbroken all the way from the U.S. to Peru.