200 Years. 200 Stories. Story 15: “Aging the rocks ”

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illustrations of fossil invertebrates
Illustrations from Synopsis of the Organic Remains of the Cretaceous Group of the United States

Aging the rocks

By the early nineteenth century, Academy members knew that fossils could provide information on the age of geologic formations in the United States. But before this potential could be realized, they had to learn more about American fossils.

Academy member Samuel George Morton was the man for the job. In collaboration with Lardner Vanuxem, he published the Synopsis of the Organic Remains of the Cretaceous Group of the United States (1834). The pair had sought and examined invertebrate fossils from the eastern and southern states, enabling them to trace Cretaceous rocks from New Jersey to Louisiana and relate the fossils to similar forms in Europe. Thanks to the work of the Academy, American scientists had the information they needed to assess the age of geologic formations.

Are your small children future researchers? Bring them to the Big Dig at the Academy where they can dig for dinosaur bones in a replica of the New Mexico Badlands! After they’re done, visit our Fossil Prep Lab to see how fossils are prepared after they are removed from the ground.

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