The Montagne Noire is a mountain range in southwestern France. It is located at the south-western end of the Massif Central in the border area of the Tarn, Hérault and Aude departments. Its highest point is the Pic de Nore at 1,210 m.
Since the 19th century trilobites make the paleontological celebrity of the Montagne Noire. One can find trilobites in every stratigraphic level, from the Cambrien to the lower Carboniferous. Certain levels of Cambrien, and especially of the lower Ordovician are famous. In this last stage, there are sometimes locally accumulations of phosphated nodules, and each one can contain a trilobite; the famous “schistes à gâteau”.
There are numerous fossils sites in the Montagne Noire. To visit them all, one probably needs a lifetime. We only made a short trip and could only visit a couple of sites.
Minerve is one of the 'most beautiful villages of France'. It’s a fortified medieval village, on top of the gorge carved by the River Cesse. In 1210, a group of Cathars, under attack in the Albigensian crusade, found refuge in the heavily fortified village. It took six weeks of siege, but eventually the village surrendered. The 140 Cathars were burned at the stake.
Nowadays is a lovely and attractive place. The landscape around the city is stunning and the gorges are the perfect hiding place for trilobites.
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Our next stop was the small village of Vélieux. Outside this place lays another middle Cambrian fossil site, where trilobites can be found. We had little time to search, but still found some nice fragments of Eccaparadoxides brachyrachys, Conocoryphe brevifrons and Bailiella seguieri, all from the lower Languedocien, Zone à Solenopleuropsis.
For more pictures see the album below.
Coulouma is a small town in the Mounts of Pardailhan to the SE of Saint-Pons. This little village is well know for it’s fossils and gave it’s name to the ‘formation de Coulouma’. The locality is built on white limestone of the base of the middle Cambrian; around the “schistes à Paradoxides” are dominating. The fossils there abound and are often in a great state of conservation.
If Ferrals was the theatre of the first Cambrian discoveries, it is especially in Coulouma that was worked out between 1893 and 1948 the complete stratigraphy of the series of the Cambrian and the Ordovician. This was mainly the work of Miquel (1893 - 1912) and of Thoral (1925 -1935).
For a visit on the spot, the best study is once more that of Abbée Courtesolle (Le Cambrien moyen de la Montagne Noire) which describes not less than 23 fossiliferous layers. Our time being limited we decided to concentrate on the famous track of the “banc du Touring Club” and fossiliferous points 14 and 16.
At point 14 one finds the oldest fauna of the corner. The rock consist of sandy shales, white and brown, without limestone nodules, but presenting small cavities filled with limonite clay. Certain plates are constellated with small pyrite iron cubes. The layer is hardly 1 meter thick and not easy to find. If you do, one discovers there rather quickly some cephalons of Baduleisia granieri (Thoral) and Pardailhania hispida.
At point 16 the schists are green with limestone nodules; they are found in broad plates and thin beds. This 5 meter thick layer is literally full of parts of trilobites. Occasionally a complete specimen is found.
Searching for trilobites.
The path of the Bench of Touring Club crosses all the levels of middle Cambrian. Along this track Courtesolle describes six interesting spots (Coulouma 3, 4, 5, 7, 8 and 9). We inspected the open grounds just in front of the breech. The place is covered with debris and one has to search for a spot were the rock is still surfacing. We were not very successful and our findings were somewhat disappointing.
Me at work near the Banc du Touring.
A strange visitor at Coulouma 18, praying mantis inspecting Gyrocystis barrandei.
This locality is well known for it’s fossils since the publications by Bergeron (1888), Thoral (1935) and Courtesolle (1973). Ferrals offers a succession of the almost complete Lower and Middle Cambrian with an abundant presence of trilobites.
One of the important outcrops of the ‘Coulouma formation’ is located on the road to Authèze in the hamlet “Causse”, close to a small quarry. This spot is one of the two hypostratotypes and offers a variety of fossils (trilobites, brachiopods and echinoderms). The layers have been dated to the middle Cambrian, from the lower Caesaraugustien to the Languedocien. This formation is composed of green pelites, locally purplished, containing intercalations of carbonated nodules.
Bailiella levyi Munier-Chalmas and Bergeron, 1889
Among the trilobites described from this outcrop are varieties of: Eccaparadoxides, Solenopleuropsis, Conocoryphe, Bailiella, Ctenocephalus, Pardailhania, Velieuxia, Agraulos, Badulesia, Calodiscus, Pseudoperonopsis, Phalagnostus, Galagnostus, Condylopyge, Phalacroma, …
Cranidium of Conocoryphe brevifrons
More images can be found in the album.