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Material name: CN8b
Synonyms: N/A
Material (geologic): Late Cretaceous (Senonian) flint

Detail of CN8b flint
Foto: Jehanne Féblot-Augustins, 2005.

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Material description

Mode of occurrence: Fragment of a large nodule.
Cortex: Some parts 1.5 cm thick, white, rough and smooth patches, transition sharp but irregular.
Colour: Pale yellowish brown mottled with brownish yellow (10YR 6/3 to 6/6).
Pattern: Highly mottled.
Appearance: Lacks homogeneity (patches of unreplaced matrix, very large clasts), dull and opaque, dry, medium-grained.
Structure: Convoluted bioturbation figures, patches of chalcedony.
Texture: Wackestone to packstone depending on the patches.
Matrix: Opaque.
Grains: 30 to 40 %, very rounded and irregularly shaped, pale or stained yellow and orange by iron oxides, quite well sorted (100 to 150 µ).
Grain composition: Numerous sponge spicules, acritarchs, small benthic and planktonic (biserial and globose) foraminifera, sea urchin radioles, echinoderms.
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.

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Locality: Jujurieux / Chenavel - Château 2, France, Ain department
Synonyms: Sampling site Bugey 66 after Féblot-Augustins
Geographical description: The material was collected along the GR 59 long-distance footpath near the castle of Chenavel, which lies between the hamlet of Chenavel and the N 84 road, overlooking the river Ain, between Poncin and Pont-d'Ain.
Geographical co-ordinates: east/x 835.95
north/y 2123.1
(Lambert zone II, NTF)

This corresponds roughly with
Lat. 46° 04' 00.9" N
Long. 005° 23' 13.4" E

Co-ordinate precision: The French coordinates of the national Lambert-grid were read from an detailed topographical map. We calculated the geographical coordinates by transforming those values on the WGS84 ellipsoid.

The location can be found on the 1:25 000 topographical map sheet 3130 E of the French Institut Géographique National.

Geology: The flint here occurs in clays-with-flints of various origins (Early and Late Cretacous), although the silex is clearly of Late Cretaceous (Senonian) age.

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: Two other Senonian flints might be found here: CN1a and CN8a.
  The nodule of CN8b
Foto: Jehanne Féblot-Augustins, 2005
Flake with thick cortex
Foto: Jehanne Féblot-Augustins, 2005


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