“[I worked] still young in the mines of Klausen and elsewhere in Tyrol, in order to learn Metallurgy; I went there by chance, and I was urged to stay by my natural very strong inclination for the universal Mineralogy, and for all the matters concerning the Science of the Fossil Kingdom.”Venetian scientist Giovanni Arduino worked in his early age as a mining assistant in the iron mines of Klausen in southern Tyrol.
In a letter dated to March 30, 1759, the Italian mining engineer Giovanni Arduino (1714-1795) proposed to the physician and fossil collector Prof. Antonio Vallisnieri the subdivision of Earth’s crust in various units of rocks. Based on his observations in the Dolomites in northern Italy, Arduino recognized a stratigraphic succession as follows:
- Primary Rocks: Unstratified or poorly stratified schist and massive rocks like porphyry and granite, making up the crystalline basement of the Dolomites. Arduino’s rock unit survived into modern chronostratigraphic charts as the Paleozoic Era (rocks older than 252 million years) and Precambrian Eon (541 million years to about 4.6 billion years ago).
- Secondary Rocks: Stratified sediments and limestone with fossils, making up the characteristic peaks of the Dolomites. In 1841 English geologist John Phillips, based on the correlation of fossils in rock strata worldwide, renamed this sedimentary succession the Mesozoic Era (252 to 66 million years ago).
- Tertiary Rocks: Poorly consolidated sediments like gravel, clay, fossiliferous sand and also younger volcanic rocks 🌋. Our modern Cenozoic Era (66 to 2 million years ago).
- Quaternary Rocks: Unconsolidated sediments found in valleys. Our modern Quaternary Period (2 million years ago to modern age).