Original meaning of the notion and term “formation” in geology

The notion of (geological) formation has gradually developed through mostly German terms: from ein Gebirge, which was used by Saxon miners for several centuries (AGRICOLA), then Schichten, Bergart (LEHMANN) and serie montana (FUCHSEL) to Gebirgsart (WERNER). The term ‘formation’ was introduced by WERNER in 1791 and its meaning was clearly defined around 1800. He included the notion of “formation” into his system of “geognostic structures”: mineral; rock (layer); formation; Earth’s crust. Therefore, it was an equivocal term from the start. It implied a geological body of certain composition, genesis and superposition (i.e. time of origination). After Werner, the term ‘formation’ was used in different ways, mostly as a synonym for a ‘system’, until 1881 when such use was forbidden. The original Wernerian sense of the term ‘formation’ (as a unit in geological levels of organisation: mineral-rock-formation-geosphere-planet) with an intentionally equivocal meaning was not restored until the second half of the twentieth century