JURASSIC OP THE PAEIS BASIN. 



569 



and are therefore the Upper Oxfordian. Tombeck (50, 55, 57, 64, 65, 

 66) endeavours to show that the zone of the last-named Ammonite 

 is above the Coral Eag ; but, his stratigraphy not being accepted, no 

 proof or probability exists of its occupying so anomalous a position. 

 Three are certainly great differences of opinion on the true position 

 of the zone of Amm. tenuilobatus, which in the Jura is supposed to re- 

 present this — some, as De Loriol, Moseh, Bayan, &c, considering it 

 Astartian, and others, as Hebert, Dieulafait, &c, making it Ox- 

 fordian. It would be hazardous to venture an opinion on this point 

 before studying the localities; but the fossils have an Oxfordian 

 facies; and if the zone really corresponds to that of Amm. mar antianus 

 in the Haute-Marne, it is certainly not Astartian. These are the so- 

 called Marls without fossils, both Upper and Lower, which have never 

 been seen separated by any true Diceras-beds. They form the base 

 at Les Lavieres, Youecourt, and Buxieres ; and the lower part of the 

 same mass constitutes the marly limestones of Maranville, and the 

 upper the cement-stones of Clairvaux, in the Aube. Further west, 

 in the valley of Laignes, the gritty character comes in again, with 

 similar fossils to those in the Meuse. In the Yonne we find the 

 true Oxfordian marls with their Harpocerata at Ancy-le-Eranc, and 

 above these the Upper Oxfordian, in the new form of massive cal- 

 careous sandstone, at Pacy, in the valley of the Armancon. The iron- 

 stone of Etivey has unfortunately not been examined ; but by its 

 fossils it might well represent the Oolite of Neuvizy, except for 

 Ammonites lunula. In the neighbouring valley of the Yonne the 

 Upper Oxfordian is recognized in the siliceous limestones underlying 

 the great white limestones of Coulanges, referred to the Corallian. 

 Great differences of opinion have been expressed about the correlation 

 of this portion. In their general work Leymerie and Eaulin (25) 

 placed the Etivey ironstone as Lower Oxfordian, as also the beds at 

 Ancy-le-Eranc, which they nevertheless considered lower still. The 

 Pacy freestones they called Middle Oxfordian, and paralleled with 

 the Coral Eag of Chatel Censoir, leaving the lithographic limestones 

 only to represent the Upper Oxfordian. This, however, has been 

 proved to be wrong by Cotteau (16, 34), who showed the essen- 

 tially Corallian character of the limestones of Coulanges and of 

 Yermanton, and discovered the Coral Eag at the base of the litho- 

 graphic limestones. The fossils and the stratigraphy are all in favour 

 of the latter author's view. M. Hebert (21, 31) recognizes in 

 the Etivey ironstone an equivalent of the ISTeuvizy, and says it 

 plunges beneath the limestones of Ancy-le-Eranc. The latter thus 

 becomes his Upper Oxfordian ; and in the same horizon with it he 

 places the freestones of Pacy, which are the equivalent of the upper 

 part only, and the limestones of Yermanton, which have been proved 

 Corallian. He considers it also the equivalent of the Creue limestone, 

 which is above the Eerruginous Oolite. Some of these correlations 

 may be rejected : but there is unanimity on the Pacy freestones repre- 

 senting the Upper Oxfordian, in spite of the recorded presence of 

 A. Babeanus. In the valley of the Loire the Upper Oxfordian is lost 

 in the unfossiliferous marls ; and in that of the Cher it must lie in 



