THE GEOLOGICAL TRAVELS OF ACHILLE DE ZIGNO IN THE DOLOMITES DURING THE SPRING OF 1846

The nobleman Achille De Zigno (1813–1892) was an Italian geologist and naturalist who studied the geological and paleontological features of the Veneto and Tirol regions. His field notes were accompanied by a great number of extremely detailed drawings. His eight notebooks were written between 1841 and 1890, starting when he was 28 until shortly before his death in 1892. He sketched mountain sections, maps, geological outcrops, and he made ink drawings of fossils together with archeological and landscape views. The most impressive features in De Zigno's notebooks are the illustrations of a great number of ‘strati’. These testify to the great effort he made to understand the age and stratigraphic order of the main geological sections in the mountains which he visited. In the spring of 1846, De Zigno crossed the already renowned Dolomites and described in detail in his notebooks the geology of the area, providing a state-of-the-art account of the geological kowledge of the Dolomites during the mid-nineteenth century. Using a geological map prepared by Leopold von Buch, De Zigno travelled from Auer (Ora) to Bozen (Bolzano), walking through all the western Dolomites, including a site in the village of Predazzo. The former locality, described by Giuseppe Marzari Pencati in 1819, was renowned for its rock layer sequence which contradicted neptunism, a dominant stratigraphic theory of the early 19th century. De Zigno, in sketching the ‘Stratified rocks’ underlying the so-called ‘Primitive rocks’ that therefore were not placed at the base of the entire stratigraphic sequence, made a significant contribution to the history of geology of the Dolomites of that time.