Visualizing the theory of the Alps: the first geological map of the western lombard prealps by Christian Leopold von Buch (1829)

In the first half of the 19th century, the Wernerian Neptunism began to reveal some flaws. It no longer seemed enough to explain the complexity of European geology. Some decades of detailed fieldwork had shed light on the difficulty of classifying the great variety of lithological formations, and especially of the ones observed by travelling naturalists during the exploration of mountains. It was likely after having examined the Auvergne volcanic area in 1802 that Christian Leopold von Buch, one of the most eminent Werner’s students, began to doubt about Werner’s geological system. The observation of the Auvergne region was a turning point in von Buch’s geological beliefs, and it was essential to establish the following theoretical basis of his ‘craters of elevation’ hypothesis The journeys, that he undertook to the Alps and Prealps in the third decade of the 19th century, contributed to strengthening the ‘craters of elevation’ theory, which was gradually included in a large-scale and geodynamic model of the genesis of mountains and the Earth’s crust. The paper aims at analysing the influence that the exploration of the Western Lombard Prealps (Lombardy, northern Italy) exerted over von Buch’s geodynamic theory of the mountains.