Jules Pierre François Stanislaus Desnoyers (8 October 18001 September 1887) was a French
geologist
A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...
and
archaeologist
Archaeology or archeology is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of Artifact (archaeology), artifacts, architecture, biofact (archaeology), biofacts or ecofacts, ...
Eure-et-Loir
Eure-et-Loir (, locally: ) is a French department, named after the Eure and Loir rivers. It is located in the region of Centre-Val de Loire. In 2019, Eure-et-Loir had a population of 431,575.Geological Society of France in 1830. In 1834, he was appointed librarian of the
Geological Society of London
The Geological Society of London, known commonly as the Geological Society, is a learned society based in the United Kingdom. It is the oldest national geological society in the world and the largest in Europe, with more than 12,000 Fellows.
Fe ...
in 1864. Parts of his collection of rare books in the earth sciences was bought by the United States Geological Survey Library at an auction in 1885. He was the Secretary of the Historical Society since its founding.
Speleological activities
Desnoyers was a spelunker. His article on caves for the ''Dictionnaire universel d’histoire naturelle'' (1841-1849) of Charles Henry Dessalines d'Orbigny broke new ground, emphasizing the role of
hydrological
Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...
phenomena in
limestone
Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...
and gypsum caves. He explored the subterranean quarries of the
ÃŽle-de-France
The ÃŽle-de-France (; ; ) is the most populous of the eighteen regions of France, with an official estimated population of 12,271,794 residents on 1 January 2023. Centered on the capital Paris, it is located in the north-central part of the cou ...
. He was one of the first to study small mammals that lived in zones of
karst
Karst () is a topography formed from the dissolution of soluble carbonate rocks such as limestone and Dolomite (rock), dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. Ther ...
ic infill.
Works
His contributions to geological science comprise memoirs on the
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...
,
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
and Tertiary Strata of the Paris Basin and of Northern France, and other papers relating to the antiquity of man, and to the question of his co-existence with extinct mammalia. In 1829 he proposed the term ''
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...
'' to cover those formations which were formed just anterior to the present, following an antiquated method of referring to geologic eras as "Primary," "Secondary," "Tertiary," and so on.Jules Desnoyers in ''
Encyclopædia Britannica
The is a general knowledge, general-knowledge English-language encyclopaedia. It has been published by Encyclopædia Britannica, Inc. since 1768, although the company has changed ownership seven times. The 2010 version of the 15th edition, ...