home ]


Material name: CN6
Synonyms: Silex Crétacé supérieur Nord - Sénonien (Campanien)
Material (geologic): Late Cretaceous (Senonian, Campanian) flint

Detail of opaque CN6 flint
Foto: Jehanne Féblot-Augustins, 2005.

top ] [ home ]

Material description

Mode of occurrence: Entirely patinated nodule fragment (cream-coloured patina).
Cortex: Remaining cortex is thin and worn, smooth, stained yellowish red, and highlighted by a white 1 cm thick desilicified band forming a sharp transition with the flint.
Colour: Light grey (2.5Y N6.5/2).
Pattern: Featureless.
Appearance: Homogeneous, dull and opaque, a little rough, medium-grained.
Structure: No particular structure.
Texture: Wackestone.
Matrix: Opaque.
Grains: 15 to 20 %, white or more seldom stained yellow by iron oxides, rounded with high to medium sphericity, contained between 100 and 250 µ.
Grain composition: frequent thin-walled monaxon spicules, less frequent triaxon spicules, numerous globose planktonic foraminifera (e.g. Hedbergella ?), some benthic foraminifera (Lenticulinea), ostracods and bryozoan fragments; abundant ligneous debris, a few iron oxides.
  Microphotograph of Globotruncanidae
Globotruncanidae (Hedbergella ?)
in a CN4c flint type.
Highly silicified.
  Photo: A. Arnaud Vanneau,
(Laboratoire de Géodynamique des Chaînes Alpines, Grenoble)

Determination: M. Caron, Université de Fribourg.
Further information: Click here for the original French description (opens in a new window), or here for more information on the attributes used in the description (use your browser's "BACK"-button to return here).
Citing: Information on citing this page can be found here.

top ] [ home ]
Locality: Poncin / Chenavel - Chatanay, France, Ain department
Synonyms: Sampling site Bugey 48 after Féblot-Augustins
Geographical description: The sampling-site is located directly adjacent to a narrow road, a bit over a kilometre to the (S)SW of Poncin.
Geographical co-ordinates: east/x 836,7 to 836,8
north/y 2124 to 2124,2
(Lambert zone II, NTF)

This corresponds roughly with
Lat. 46° 04' 32" N
Long. 005° 23' 52" E

Co-ordinate precision: As the site is a few hectares in size, precision is not of the highest importance, but the coordinates lie well within the area.
The geographical coordinates point to a spot near the centre of the site.

The location can be found on the 1:25 000 topographical map sheet 3230 W of the French Institut Géographique National.

Geology: The material from this site can be classified as surface-collected flint or in eroded gulleys, Chenavel sector, clays-with-flint of various geological origins (Early and Late Cretaceous); Unit S (Rs).

Map of all sampled localities of Late Cretaceous flint in the Bugey (PDF, 54 KB, opens in new window).

Type of source: Secondary.
Other types of flint: Besides the Campanian CN1a material, several types of Late Cretaceous material can be found here (CN1a, CN2a, CN2c, CN4a and CN4b), as well as Early Cretaceous Ht3 flint.
  Coarse light-coloured flint
Foto: Jehanne Féblot-Augustins, 2005


Last modified on:
November 15, 2005
Contents primarily by:
Jehanne Féblot-Augustins
Comments to: