2012-12-05

The Geological Natural Reserve at Hettange -Grande (F)





Tout le texte en français en italique, voir au dessous






Place: Hettange Grande in France.   Location: N  49.41104211   E 6.15844311

The Geological Natural Reserve at Hettange -Grande (France)
The sandstone quarry "Gries" was exploited   until the mid-twentieth century for the extraction of construction materials (stones, rubble, sand).
This pit  has been introduced by Eugene Renevier in 1864, as an international benchmark (Stratotype ) for a new geological stage (= deposits of a certain age), called the Hettangian ( 196,5–199,6 mya, first stage of the Lias-Jura) See wiki Jurassic for subdivisions of this period
During the  Hettangian period,  the Hettange region is located below a sea, at a short distance from a land mass located further north which now forms the bulk of the regions of Eifel and  Hunsrück in Germany and of the  the Ardennes in France, Belgium and  Luxembourg. In this warm and shallow sea  alternating carbonate mud clay and carbonate sands left behind benches of  limestones and marls  with fossils like  "Devils toenails ( Gryhaea, bivalve mollusks like oysters close today). Only the Upper - Hettangian (approximately -201 000 000 years), is visible in the quarry, the other, older  stratotypes are lying too deep to be visible. We find here fossils of ammonites.

La Réserve Naturelle Géologique d'Hettange Grande
Localisation: Hettange -Grande, France   coordonnées: N  49.41104211   E 6.15844311  
Les grès de la carrière Gries furent exploités jusqu’au milieu du XXème siècle pour l’extraction de matériaux de construction (pavés, moellons, sable). 
Cette carrière a été  introduit comme référence internationale (= stratotype) d’un nouvel étage géologique (= dépôts d’un âge donné), l’Hettangien, par Eugène Renevier en 1864. L'Hettangien est la premiere étage de la période Jurassique  (Lias) Voir Wiki Jurassique pour la sub-division de la période.
Pendant l’Hettangien, la région d’Hettange se trouve sous une mer, à faible distance d’une terre emergée située plus au nord et qui forme aujourd’hui les massifs de l’Eifel et le Hünsrück en Allemagne et les Ardennes en France, la Belgique et Luxembourg. 

Dans cette mer, qui était chaude et peu profonde, se déposent en alternance des boues argilo-carbonatées et des sables carbonatés à l’origine des bancs pluridécimétriques de calcaires et de marnes du "calcaire à gryphées"(mollusques de type bivalves proches des huîtres actuelles). 
Dans la carrière on voit l’Hettangien supérieur (à -201 millions d’années environ),les stratotypes plus vieux  ne sont pas visibles ( plus profond). On y trouve des fossiles d' ammonites.

Images:

 Monument at the entrance of the pit
Monument à l'entrée de la carrière

 The rocks of the Hettangian layers in the pit
 Les roches des couches Hettangien dans la carrière



Ammonites which have cross -cut dimension of ca 40 cm are normal in the pit.
Ammonites avec un coupe en traversde  ca 40 cm sont courantes dans la carrière



Internet / references


Special thanks to Jean-Yves Ringenbach for the disponibility of the images 
Un grand merci à Jean-Yves Ringenbach pour la disponibilité des images

2012-12-03

An old collection from Spiennes (B) Une vieille collection de Spiennes (B)


An old collection from Spiennes (B)
Une vieille collection de Spiennes (B)

Tous les textes en français, en italiques




Mining pick from Spiennes, collection JY Ringenbach
 Pic minière de Spiennes, collection JY Ringenbach
Flint mines of Spiennes (B)

The flint mines in Spiennes in Belgium are very well known, and belong  since  2000 to the UNESCO World Heritage, (UNESCO nr 1006) .The flint mine complex is one of the biggest in Europe ( ca 100 ha.).
The site is known by the fieldnames "Petit-Spiennes" and the Versant de la Wampe, spread over two plateaus, one at the west named "Pa'd'à l'liau"  and one at the east the "Camp-à-Cayaux".
The underground mining started between 4400 and 4200 BC by the members of the Michelsberg Culture, and  the mines were exploited till ca. 750 BC. The complete combination of a direct link with a settlement nearby and the finds of many pottery sherds makes the flint mines of Spiennes a very interesting object for  studying the Middle Neolithic period in detail.
In vertical shafts ranging between ca 3,5 till 16 meters deep the flint from the desired flint banks was mined.
The end of the exploitation of the mines at 750 BC is based on the find of a separate atelier at the top of a pit enclosure.The images presented here come from the collection of Mr.André Huberty, and were collected in 1965 .Artifacts from a particular cultural heritage!

Silex du mines de Spiennes (B)

Les mines de silex de Spiennes en Belgique sont très bien connues, et appartiennent depuis 2000 au patrimoine mondial de l'UNESCO (UNESCO n ° 1006). Le complexe minier de silex est l'un des plus grands d'Europe (environ 100 ha.). Le site est connu par les champs nommés "Petit-Spiennes» et le "Versant de la Wampe", réparties sur deux plateaux, l'un à l'ouest, nommé "Pa'd'à l'Liau" et l'autre à l'est, le «Camp-à-Cayaux ". 

L'exploitation minière souterraine a commencé entre 4400 et 4200 avant J.-C. par les membres de la culture de Michelsberg, et les mines ont été exploitées jusqu'à env. 750 av. La combinaison complète d'un lien direct avec une colonie voisine et les découvertes de nombreux tessons de poterie fait les mines de silex de Spiennes un objet très intéressant pour l'étude du Néolithique moyen en détail. Dans des puits verticaux compris entre environ 3,5 jusqu'à 16 mètres de profondeur, le silex des bancs était extrait souhaités. 
La fin de l'exploitation des mines à 750 avant JC est basée sur la découverte d'un atelier séparé dans la partie supérieure d'une enceinte fosse.
Les images présentées iciproviennent de la collection de Mr.André Huberty, et ont été recueillies en 1965. Les artefacts provenant d'un patrimoine culturel particulier!

IMAGES

Collected artifacts from Spiennes (1) Mining picks, processed axe,  blade core
 Artefacts recueillis à  Spiennes (1) Des pic minières,  hache taillée, nucléus à lames


Collected artifacts from Spiennes (2)  Mining picks
 Artefacts recueillis à  Spiennes (2) Des pics minières

Collected artifacts from Spiennes (3): Picks and cores
Artefacts recueillis à  Spiennes(3) Des pics et nucléi

Blade coreNucléus a lames
Mining pick Pic de mineur
Finished axe Hache taillée

Roe antler used for the mining activities  Bois de chevreuil utilisé pour les activités mineurs
Semi finished chisel  Ébauche de ciseau
Discoid core  Nucléus discoïde

 Drill on an end -struck blade Perçoir sur lame

Hammerstone Percuteur
Left proximal portion of blade two opposite notches retouching with retouche on the whole length 


À gauche , partie proximale de lame 2 retouches à encoches opposées avec  retouche sur la longueur

Various blades, showing patina ( left) and the fresh color of the flint Lames différentes , montrant la patine blanche  (à gauche) et la couleur fraîche du silex
Blades from Spiennes. There is great similarities with the Rijckholt (NL) flint
Lames de Spiennes. Il ya de grandes similitudes avec le silex Rijckholt (NL)


References/ internet

Hélène Collet, Anne Hauzeur, Jacek Lech (2008) : The prehistoric flint mining complex at Spiennes (Belgium) on the occasion of its discovery 140 years ago - tiré-à-part des actes du colloque "Flint Mining in Prehistoric Europe" 2008
SRPH The Spiennes site (English text)
De Neolithische vuursteenmijnen van Spiennes (Nederlandse tekst)
World Heritage Net Item 1006


With special thanks to Jean-Jo Paquay for making  the images available for the public.
Remerciements à Jean-Jo Paquay pour faire disponible les photos. Toutes les images: J.J Paquay.

2012-12-02

Re- use of flint material during the prehistory



Flint, the raw material used to make tools, not always was available in such quantities to make any desired  tool for the moment. During  the Palaeolithic,  the landscape was open, and during the relative cold periods  flint must have been  easy to find at exposed surfaces.
Neanderthal men made large tools, as the raw material was accessible both in limestone layers ( as banded  'banks') and at  the riverbanks, but they also transported the raw material into their camps over large distances, demonstrated by several  "manuports" in their local  campsite(s). 
The best quality flint was used in the base camps ( mostly in the caves more to the south). K. di Modica (1) placed the use of the cretaceous flint in the local use of raw material ranging up to 5 km. 
Further from this location, (> 5 – 15 km) the standardization of tool-production and material -use diminished, to locations up to 50 km and more where the raw material was not classified no more, so they used all kinds of ground stones/ flint. 
Middle -Palaeolithic tools and flint implements of such temporarly, 'distant' sites  show both the Levallois technique and superior quality flint, so in this raw material choice we might conclude (i.c.) the Middle Palaeolithic base-camp at Visé-Lanaye Caestert in Belgium was ( for temporarily reasons) very important.
During the ( later) Mesolithic, the landscape was dominated by large forests and bush, so useful flint was hard to find, except at the riverbanks and the former river terraces, where rolled flint was available. We might expect a careful use of the material. The use of microliths  in the standard assemblage was not only because of the lack of good quality  flint  for the production of very tiny tools, but  this was also the result of a different game hunting and an 'easy and light ' transport of their tools and weapons in a nomadic lifestyle. During the stone ages, flint tools were reduced all the time,e.g. when an artifact broke, was used up, or simply needed to be transformed into another tool with another purpose.This is illustrated by the short "chaine opératoire".
During the Neolithic, flint was available to make tools, by large scale, systematic  mining activities.  Recycled tools which are easy to determine as recycled tools are those tools that once were polished, broke and afterwards were transformed into another tool.
The examples in this article contain late Neolithic polished axes that were re- used by flaking them and use them as scrapers. 
The polished surface remained partially intact for contact with the hand. In this recycling idea we can even understand more about the use of ground stone tools, such as slate and quartz.


In the study of lithics it's always important to consider the stage in which an artifact was, when it was left in the landscape. Artifact size diminishes during the use, and artifacts were resharpened or reworked all the time. Blanks are artifacts that could be adapted into desired tools and only were shaped in a rough form.

Re-polished small axe from the Neolithic (Michelsberg-Culture) found near Eijs (Limb)
 Ventral view of a former polished axe, re-used for the production of flakes

Dorsal view of the polished axe fragment

 Image above: the left two scrapers on the image are made of former polished axes from the Neolithic period; the scrapers at the right belong to the same polished axe, ( same Ryckholt flint) but these fragments don't show polish; they were found together, so all 4 scrapers are made of recycled material and got a second life (comp. splintered pieces / "Ausgesplittertes Stück" pierres esquilées - Fiedler 1979)

References/ internet/ Litt.
(1) K. Di Modica & C. Jungels (ed.). Paleolithique moyen en Wallonie: la collection Louis Eloy (Collections du Patrimoine culturel 2).  . 2009. Namur: Service du Patrimoine culturel; p.52 (image)
Fiedler L, (1979) For­men und Tech­ni­ken neo­li­thi­scher Stein­ge­räte aus dem Rhein­land, in Rhei­ni­sche Aus­gra­bun­gen, Band 19, Bei­träge zur Urge­schichte des Rhein­lan­des III, Köln, 1979, S. 118