THE GEOLOGY OF THE REGION AROUND PARIS
The preparation of his report on geology obliged Cuvier to become well informed--if he was not already--about recent and current research in that field. In particular, his review of work on the succession of formations in specific regions must have led him to appreciate what such a survey could do for his own research. He had entered the field of fossil anatomy with the scarcely examined assumption that all fossil bones dated from the same "catastrophe." As those from around Paris grew in importance, to become almost the centerpiece of his anatomical research, he became aware that they were decidedly more ancient than those of the mammoths and similar animals: the Paris fossils came from within a thick pile of bedded rocks, whereas the others were confined to loose superficial deposits. His tentative suggestion (text 6) that fossil bones became more unlike those of living animals as they were traced back into more ancient formations depended on some sense of their relative ages. But that sense could only come from attending to the work of those who had carefully plotted the relative positions of rock formations.
At some point--probably a year or two before his first lectures on geology (chapter 8)--Cuvier had begun collaborating with Alexandre Brongniart on a study of the rocks around Paris, in order to fix more