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L’étude de la controverse sur la limite des terrains crétacés et tertiaires, plus particulièrement la place à donner aux terrains daniens, révèle l’évolution de la géologie au cours du XIXème siècle. D’un champ d’étude descriptif et classificatoire, elle devient histoire de la vie à la surface de la Terre. En 1822, la description du bassin de Paris par Cuvier et Brongniart où chaque couche est caractérisée par la nature des roches et ses fossiles, devient « le » modèle de référence qui montre entre craie et terrains tertiaires une discontinuité lithologique, stratigraphique et paléontologique. C’est en termes d’appartenance à l’une ou l’autre que se pose le problème du calcaire de Faxe décrit par Forchhammer au Danemark en 1825 et du calcaire pisolithique en France en 1836, attribués aux terrains tertiaires par leurs descripteurs et à la craie par les théoriciens. La controverse qui se développe alors sur la position de ces terrains rassemblés en 1846 sous le nom d’étage danien par Desor, révèle deux changements profonds dans la pensée géologique du XIXème siècle : d’une part, le changement du cadre de pensée où la représentation spatiale des couches devient temporelle ; d’autre part, l’opposition catastrophisme-transformisme d’où émerge la notion de limite en stratigraphie et qui trouvera son épilogue avec la démonstration de la non-existence des générations spontanées. Le critère d’« extinction » est proposé en 1878 par Cope pour définir une limite. Ainsi caractérisée, la limite Crétacé-Tertiaire devient un évènement dramatique affectant la surface de la Terre entière, sans plus aucun parfum religieux et idéologique. La géologie est devenue une science historique. / The study of the controversy on the boundary of Cretaceous and Tertiary formations, more specifically the place given to Danian, reveals the evolution of geology through the nineteenth century. From a descriptive and classificatory practice of science, geology becomes an history of life on Earth. In 1822 the description of Paris Basin by Cuvier and Brongniart, in which each layer is characterized by the nature of its rocks and fossils, becomes “the” reference model. It shows, between chalk and tertiary formations, a lithological, stratigraphic and paleontological discontinuity. The limestone of Faxe described by Forchhammer in 1825 in Denmark and the pisolithic limestone in France in 1836 were first discussed in terms of an association either to chalk or to Tertiary formations. The original discoverers associated them to Tertiary formations, whereas theorists associated them to chalk. The controversy which develops about these formations, gathered by Desor in 1846 under the name of Danian stage, reveals two profound changes in the manner geology is thought: firstly, geology shifted from a spatial representation to a temporal representation of the layers; secondly, the opposition of transformism to catastrophism, which the notion of boundary in stratigraphy stemmed from, meets with its end with the demonstration that spontaneous generation does not exist. The criterion of "extinction" is proposed in 1878 by Cope to define a boundary. Thus characterized, the Cretaceous-Tertiary boundary becomes the hallmark of a dramatic event affecting the entire surface of the Earth, with no more any religious and ideological perfume. Geology had become a kind of historical science.

The central figure in this thesis is Robert Jameson (1774-1854), geologist, mineralogist and Professor of Natural History at the University of Edinburgh. Jameson's geological work is examined in relation to the social and intellectual interests of contemporary civil society, and in particular, in terms of the debates in Edinburgh between Huttonians and Wernerians (of which group Jameson was one) concerning the nature of geological evidence and of theory in geological explanation. This thesis is also concerned to bring into sharper focus the state of, and public interest in, the earth sciences in Scotland in the first two decades of the nineteenth century. In this regard, analysis centres upon the conceptual basis and scientific methods behind Jameson's work and upon the making of natural knowledge as a situated intellectual and social concern. The thesis has eight chapters. Following an introduction and literature review they are, respectively, concerned with showing that in societies, teaching, museology, fieldwork, laboratories and through publications, Jameson's scientific 'methodology' conformed in large part to the Baconian taxonomic and descriptive elements of Wernerianism. This thesis also suggests that scholars have hitherto misrepresented and overplayed the 'theoretical' nature of Jameson's work, and in so doing, have only characterised the debate between Huttonians and Wemerians as a conflict between rival theories. In re-examining the several activities and the conduct of Huttonians and Wernerians (in this case Jameson) in a variety of settings, a rather different understanding of the nature of debate is here advanced. Specifically, it is shown that rivalry between Huttonians and Wernerians in the sites stated above might be better understood not in terms of two opposing theories, but, rather, as a rivalry between a vigorously held theory on the one hand (proponents of Huttonianism) and, on the other, a conviction about the prematurity of theory and importance of a Baconian empirical approach. The thesis also suggests that understanding the intellectual contexts to such geological enquiry depends importantly upon knowing something of the social and civic nature of scientific 'ownership', institutional authority, personal reputation and the proprietorial control of local scientific knowledge.