Quaternary sediments collection

Quaternary sediments are formed by the different processes of rock alteration and then by the transport and deposit of the elements resulting from this alteration. They are witness to the climatic and geographic phenomena which have shaped the landscapes associated with human evolution.

History

The quaternary sediment collection consists of different samples taken from several dozens of prehistoric, palaeontological or geological sites studied by researchers at the Muséum’s Prehistory department since the 1980s.

The samples thus archived mainly come from sites located in western Europe (France, Spain, Italy, Great Britain, Belgium, Germany) and eastern Europe (Ukraine, Georgia), continental Asia (China, Cambodia, India, Pakistan) and Asian islands (Indonesia, Philippines, Japan), and from Africa (Morocco, Tunisia, Ethiopia, Namibia).

These sites cover a time period corresponding to the end of the Tertiary period (between 6 and 2.6 million years ago) and the whole Quaternary period, i.e. from 2.6 million years ago to the current day. The stratigraphic interval covered stretches from the Lower Cretaceous up until the Tertiary period, depending on the exploration. Work is currently underway to make an inventory of, classify and computerise the sediments collection and the documents relating to these samples (ground surveys, analysis results, datings, etc.).

Activities

Quaternary geology brings together a set of disciplines that aim to study the evolution of landscapes and environments over the last three million years, as well as the influence of these modifications on human populations.

The main purpose of these disciplines is to study the sediments formed by the alteration of old rocks (by various physical and chemical phenomena) and then by their transport (by water, wind or simply gravity), and finally the deposit (on river banks, in lakes and caves, etc.) of the solid elements (sands, gravel, clays, etc.) or solutions (carbonates, iron, manganese, etc.) resulting from this alteration.

Based on the study of these deposits, some of these disciplines will characterise the climatic conditions that prevailed in different areas of the globe (geomorphology, sedimentology), while others will establish chronologies of the different events such as climate changes or human settlements (geochronology) and others again will seek to define the limits of each of these events (micromorphology, pedology).

In order to put these different methods to work when studying an archaeological, palaeontological or geological site, it is important to sample the sediments characteristic of the different environments.

Several types of samples are thus systematically taken:

  • “Bulk” sediment sampling of each level in order to characterise the means of transport and deposit of minerals and to date when this occurred.
  • Column sampling of the interfaces between these levels in order to characterise the conditions of transition between the different stages in the site’s formation.
  • For cave sites, sampling of blocks or cores of the stalagmite floor to study the climatic variations and to date the different phases in the formation and/or human occupation of the cavities.

After processing and study, each of these samples are destined to be included in what is known as the “quaternary sediment collection”. This collection currently holds several hundreds of samples of sands, micro-morphological cores and blades, and speleothem cores and samples (carbonated cave formations, such as stalactites). All of these elements together have a considerable value, both scientifically and for our heritage, since they most often come from sites or outcrops that have now disappeared, as a result of urbanisation or archaeological digs.

The creation of a database to bring together the different information resulting from studying the sediments is planned but yet to be undertaken. It will gather together information collected in the field (stratigraphic sections), micromorphological blade analyses, gamma spectrometry results (nature and radioelement concentration contained in the sediment), and petrographical (nature of the minerals), granulometric (size and general aspect of the grains) and mineralogical analyses of these deposits. A bibliography will be linked to this, detailing the different publications produced from the sediment studies.

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