JURASSIC OF THE PARIS BASIN. 



523 



on the south (Cote du Noeulon). In the first the marly limestone 

 " a, A. Holbeini et A. marantianus " is said to be seen above the 

 Diceras-beds ; and in the second the Diceras-beds are said to be re- 

 duced to almost zero in the midst of the clays. If "A. marantianus 

 is found " (in beds which lie ?) " above 50 metres of Diceras-beds at 

 Baxieres," and (in beds which lie ?) " above 30 metres of the same 

 at Heu," still one swallow does not make a summer, and the rare 

 occurrence of such a fossil would no more make the zone of Amm. 

 marantianus Corallian than the occurrence of species so near to A mm. 

 cordatus that they cannot be distinguished in Supracoralline or even 

 Kimmeridgian beds makes the zone of Amm. cordatus a part of the 

 Kimmeridge Clay. The actual section seen at Vouecourt is quite 

 consonant with all that has been seen before, except that in the 

 Eavin du Heu the lower part of the section is much distorted, and 

 the Corallian beds on the north appear to be let down, as by a fault, 

 to too low a level in relation to the Oxfordian on the south. The 

 section commences at the top with compact limestones, as at Buxieres ; 

 then, below, come rubbly limestones with abundant Terebratula 

 Leymerii, T. tetragona, &c, also Rhynchonella pinguis, Pleuromya 

 Voltzii, Anatina magnifica, Mytilus perplicatus, Pinna granulata, Pec- 

 ten inoequicostatus, and Nerita Royeri. Next follow marls and marly 

 flags containing the same Brachiopoda, Mytilus, and Pecten, with 

 Area rhomboidalis and Pholadomya cor ? These are the beds which 

 contain Amm. marantianus, according to Tombeck ; if they do, it has 

 not its usual associates, and is therefore out of its place. Below 

 comes a great mass of limestone capped by a rosy large-grained 

 oolite ; but the base is not seen, the whole being so disordered. In 

 these were seen Lima Iceviuscida, Pecten articidatus, and Rliyncho- 

 neUa corallina. No doubt the Diceras-beds do not here make such 

 a show ; but the succession above shows that we are at their top, 

 and there may be much more than appears. It is below all this 

 that the whole road along the Noeulon is cut ; and it shows only 

 the marls and marly limestones of the Les-Lavieres and Buxieres 

 cuttings. 



All the other sections in and near the Marne valley quoted by 

 Eoyer or Tombeck, and those seen by the Geological Society of 

 France on their visit in 1856 (19), are perfectly consonant with the 

 present reading, and may be easily interpreted. 



To complete the account of these lower beds, as developed in the 

 department of the Haute Marne, we must make a digression towards 

 the west to Maranville and La Mothe. At the first locality on the left 

 bank of the Aube we are supposed to recognize the Corallian in the 

 midst of the marls ; there is, however, nothing Corallian about them. 

 The rocks seen in the hills here are a series of marly limestones far 

 more argillaceous than any seen before, having a thickness of 120 

 feet. They are most lithographic above, and most marly below, the 

 intervening portion being most fossiliferous. The fossils seen are Ox- 

 fordian, viz. Alaria bispinosa, Astarte striatocostata, Littorina Meriani, 

 Ostrea multiformis, Exogyra spiralis. There is nothing, therefore, 

 here to identify any portion as having a position above the Diceras- 



