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Material name: CC4a
Synonyms: Silex Crétacé supérieur Centre - Sénonien.
Material (geologic): Late Cretaceous (Senonian) flint.

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

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Material description

Mode of occurrence: Irregular nodules of various sizes.
Cortex: Worn to partially rolled, thin (<1 mm), brown, smooth, transition sharp.
Colour: Light greyish brown bordering on light olive brown (2.5Y 5/2 to 7/2).
Pattern: Faintly splotched/mottled, with a few small patches of unreplaced matrix and some pale-coloured clasts (4 mm max.).
Appearance: Reasonably homogeneous material with a medium lustre, opaque, smooth, medium to fine-grained.
Structure: Convoluted bioturbation figures.
Texture: Mudstone to wackestone, with a 1 mm wide packstone band below the cortex.
Matrix: Opaque.
Grains: 7.5 to 15-20 %, generally fuzzy and irregularly shaped, contained between 80 and 250 µ (mean size 180 µ), occasionally stained yellow by iron oxides; more distinct skeletal grains (500 µ max.) concentrated below the cortex.
Grain composition: Bryozoan fragments, various foraminifera (biserial, planispiral), some sponge spicules, rare hollow spheres 100-125 µ across (sponge microscleres); rare detrital quartz.
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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Les Côtes
Locality: Andert-et-Condon / Andert - Les Côtes, France, Ain department
Synonyms: Sampling site Bugey 52 after Féblot-Augustins
Geographical description: N/A
Geographical co-ordinates: east/x 858,4
north/y 2092,2
(Lambert zone II, NTF)

This corresponds roughly with
Lat. 45° 46' 51" N
Long. 005° 39' 36" E

Co-ordinate precision: The coordinates given were taken from a large-scale map, and won't be off by more than 50 metres.
The latitude/longitude coordinates are a direct transformation of these data on WGS84 and are accurate to the same level, so give or take an arc-second or two.

The location can be found on the 1:25 000 topographical map sheet 3231 E of the French Institut Géographique National.

Geology: According to the geological map, the substrate is of Oligocene age (unit 'g'). The flint istself originates in Late Cretaceous (Senonian) sediments and lies here in a secondary position.

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: Apart from the CC4a flint, quite a lot of other Late Cretaceous (Senonian) flints can be found here, CC2, CC3a, CC3b, CC4b as well as Early Cretaceous (Urgonian) material of the Ur-type
  Small piece of CC4a flint
Foto: Jehanne Féblot-Augustins, 2005
Upper Cretaceous flint with cortex
Foto: Jehanne Féblot-Augustins, 2005


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