Foto: Jehanne Féblot-Augustins, 2005.
- Chatanay
- Le Mortaret
- La Bierle
- Les Brovières 4
Sampled sites:
| Material name: | CN4a |
| Synonyms: | Silex Crétacé supérieur Nord - Sénonien (Campanien) |
| Material (geologic): | Late Cretaceous (Senonian, Campanian) flint |
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Foto: Jehanne Féblot-Augustins, 2005. |
Sampled sites:
|
| Mode of occurrence: | Irregular nodules of various sizes. |
| Cortex: | Worn and thin, smooth to slightly rough, brownish yellow, transition sharp. |
| Colour: | Greyish brown to light brownish grey (2.5Y 5.5/2). |
| Pattern: | Flecked (light millimetric inclusions), rare pale spots (unreplaced matrix). |
| Appearance: | Poor homogeneity (diaclases, large patches of unreplaced matrix), medium lustre, semi-opaque; moderately smooth, medium grained. |
| Structure: | A few micro-vugs. |
| Texture: | Wackestone/packstone. |
| Matrix: | Subtranslucent to translucent. |
| Grains: | 30%, pale, subangular with high (100-300 µ) to low (1 to 2 mm) sphericity, often surrounded by recrystallization haloes. |
| Grain composition: | Mainly thin ramified Cyclostoma bryozoans (section 250 µ), some rare Cheilostoma bryozoans, a few globose (Hedbergella planispira) and biserial planktonic foraminifera, hardly any sponge spicules. |
| 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. |
| 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 |
| 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 CN4a material, several types of Late Cretaceous material can be found here (CN1a, CN2a, CN2c, CN4b, and CN6), as well as Early Cretaceous Ht3 flint. |
hi.jpg&w=597&h=575&i=Foto: Jehanne Féblot-Augustins, 2005. "Click for a high-res version (81 Kbytes)") Foto: Jehanne Féblot-Augustins, 2005 |
| Locality: | Leyssard / Solomiat - le Mortaret, France, Ain department |
| Synonyms: | Sampling site Bugey 58 after Féblot-Augustins |
| Geographical description: | The sample was collected on some fields directly to the southwest of Solomiat, a very small village/hamlet just off the main D 979 road, approx. 10 kilometres west-northwest from Nantua as the crow flies. |
| Geographical co-ordinates: |
east/x 842,6 north/y 2135,6 (Lambert zone II, NTF)
This is equivalent to |
| Co-ordinate precision: |
The coordinates given were taken from a large-scale map, and will be accurate to a level of approx. 50 metres. The latitude/longitude coordinates are a direct transformation of these data on WGS84 and are accurate to the same level, the high presicion to the arc-second is given to prevent the introduction of addition inaccuracy. The location can be found on the 1:25 000 topographical map sheet 3229 W of the French Institut Géographique National. |
| Geology: |
According to the geological map, the substrate consists of clays-with-flint (unit Rs), resulting from the decalcification of Late Cretaceous formations. 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 CN4a-type, the CN4c variety can be found here too. |
hi.jpg&w=604&h=590&i=Foto: Jehanne Féblot-Augustins, 2005. "Click for a high-res version (83 Kbytes)") Foto: Jehanne Féblot-Augustins, 2005 |
| Locality: | Poncin / La Bierle, France, Ain department |
| Synonyms: | Sampling site Bugey 62 after Féblot-Augustins |
| Geographical description: | The material was collected on a south-facing slope overlooking the eastern "outskirts" of Poncin, 20 kilometres SE of Bourg-en-Bresse. |
| Geographical co-ordinates: |
east/x 838,3 – 838,6 north/y 2125,3 – 2125,5 (Lambert zone II, NTF)
This corresponds roughly with |
| Co-ordinate precision: |
With a surface of several hectare, the site is quite extended, so no bother about the precision of the coordinates The latitude/longitude coordinates point somewhere to the centre of the area, so don't bother about the single seconds (in this area, 1 second of latitude is ca. 30 metres on the ground, a longitudinal second approx. 20 metres) The location can be found on the 1:25 000 topographical map sheet 3229 W of the French Institut Géographique National. |
| Geology: |
The site is located on fluvio-glacial deposits from the Würm I and II stages (units agl a-b on the geological map), in contact with Aquitanian sediments (Early Miocene, unit ml). This results in a mix of Upper Cretaceous an Cenozoic flints being present at this site. The CN4a type can be dated to the Campanian. 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: | As so often on secondary sites, quite a lot of other types of flint can be found here, mostly of Late Cretaceous age: CN2b, CN4b, CN4c, as well as the Cenozoic "silex lacustre" of the T1 type. |
hi.jpg&w=744&h=580&i=Foto: Jehanne Féblot-Augustins, 2005. "Click for a high-res version (113 Kbytes)") Foto: Jehanne Féblot-Augustins, 2005 |
| Locality: | Jujurieux / Chenavel - Les Brovières 4, France, Ain department |
| Synonyms: | Sampling site Bugey 69 after Féblot-Augustins |
| Geographical description: | The sampling site is one of a small cluster, together with Les Brovières 2 & 3, which lies approx. 150 metres above the bottom of the valley in a bend of the river Ain, about a kilometre and a half southwest of Poncin, and a kilometre to the north of Chenavel. |
| Geographical co-ordinates: |
east/x 836.4 north/y 2124.1 (Lambert zone II, NTF)
This corresponds with |
| Co-ordinate precision: |
The coordinates given were taken from a large-scale map, and are within approx. 50 metres of the actual spot. The latitude/longitude coordinates are a direct transformation of these data on WGS84 and are accurate to the same level, the apparently high precision to the second is given to prevent the introduction of a rounding-error The location can be found on the 1:25 000 topographical map sheet 3130 E of the French Institut Géographique National. |
| Geology: |
The sample consists of surface collected flint from an patch of clays-with-flints, which represent the residue of weathered material of various geological origins (Early and late Cretaceous). 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: | This is also the only source of CN7 flint sampled until now. |
hi.jpg&w=691&h=575&i=Foto: Jehanne Féblot-Augustins, 2005. "Click for a high-res version (91 Kbytes)") Foto: Jehanne Féblot-Augustins, 2005 |
hi.jpg&w=867&h=590&i=Foto: Jehanne Féblot-Augustins, 2005. "Click for a high-res version (91 Kbytes)") Foto: Jehanne Féblot-Augustins, 2005 |
| Last modified on: November 25, 2005 |
Contents primarily by: Jehanne Féblot-Augustins |
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