Vireux - Molhain

One of my father's favourite outcrop is the so called 'Mur des Douanniers'

in Vireux-Molhain (Ardennes - France). If you follow the D.47 from Vireux-Molhain to Treignes, you can not miss this famous spot, it's just before crossing the border into Belgium. Since 1991, the site is has become a natural reserve where fossil collecting is strictly prohibited. The penalty for illegal collecting is high, and the French police seem often present in the neighbourhood. Information panels give an overview of the taxa that were found here. Most of the names given are not correct. According to these panels the site belongs to the St. Joseph Formation. Recent research by V. Dumoulin and S. Blockmans assigns the outcrop to the Membre du Vieux Moulin, a new nember of the Jemelle Formation (Eifelian age), which fits better with the presence of the trilobites Geesops and Septimopeltis.

My father visited the site as a youngster and found the two phacopines that occur here, Geesops sparsinodosus gallicus Struve, 1982 and Pedinopariops sp. A lot of material was collected before the closure and so trilobites of Vireux are often offered for sale. We were able to buy some additional species like Gerastos catervus (van Viersen, 2006a), Cyphaspis n. sp. (van Viersen, 2006a) and nice Asteropyginae gen. & sp. indet. on fossil shows. Last year we found nice partly enrolled Cornuproetus sp. on a temporary outcrop not far from the famous 'Mur des Douanniers'. The rare ones (Lichids and Odontopleurids) on the contrary are very hard to get.

One can understand the French authorities closed the site; some fossil hunters were using heavy equipment and did a lot of damage. However the situation of the outcrop today is far from ideal. There is no physical protection (roof or so) and nature, especially erosion continues to do its work. The cliff is partly overgrown and its top layer is completely disintegrated; all fossils it contained are lost forever. There was no or poor research on trilobites from Vireux-Molhain, and it's only recently that van Viersen started a nomenclatural revision of the trilobites from this Early Eifelian Fossil-Lagerstätte. To do so he has to base on the many specimens collected by amateurs before closure and preserved in private collections and museums. A limited and temporary re-sampling at the outcrop would certainly allow a more thorough research.

The situation of the 'Mur des douanniers' in Vireux-Molhain clearly proves that any fossil collected even by an amateur, is a fossil saved; there where fossils remaining in the rock are often lost for research.

 

Vireux