Some historical regards concerning the origin of the concept of sedimentary facies

Abstract

Both the origin and the meaning of the concept of facies when applied to sedimentary formations are discussed. This term was coined by the Swiss geologist Amanz Gressly in 1838, from his studies in the East Jura massif, north of the Alps. Gressly considered the horizontal and vertical dimensions of the strata, and along with the lithic content he also included the palaeontological component. Thus, on the one hand, it could be deduced the environmental features of the sedimentary environment, as well as the climatic conditions and the tectonic factors that would have conditioned its formation, and, on the other hand, establishing the palaeogeographical and palaeoecological characteristics of a region based upon the principles of natural causality and actualism. Previously, during the 17^th, 18^th, and 19^th Centuries, some authors such as John Woodward, in 1695, in different areas of England, and Benoît de Maillet, in 1748, on the Mediterranean coasts of North Africa, based upon the Neptunism’s castastrophist ideas, had pointed out the importance of considering the fossil remains for better understanding sedimentary formations. In the early 19^th century, George Young and John Bird, studying the Yorkshire coast, in 1822, had also observed the horizontal connection between some parts of many of the strata, but not as a whole in relation to the fossils. In those years, the major units of the geological column were being defined, and at the same time the Neptunist current was being abandoned. Geology therefore needed a new theoretical framework in which to develop the new researches. Gressly laid the foundations for a new way of understanding the stratigraphical record with his definition of facies.