520 



J. F. BLAKE ON THE UPPER 



on ascending the hill we find the oolites above worked in a 12-foot 

 face, and overlain by a shelly limestone crowded with Rhynchonella 

 pinguis ; this is followed by more compact limestone, some portion 

 of which may possibly be slightly oolitic ; but there is nothing re- 

 markable to distinguish the whole series, nor is its relation to the 

 Diceras-beds below very clear. 



Succeeding these compact limestones comes no great thickness of 

 irregular limestones, such as have been seen to characterize the 

 Astartian beds near Gondrecourt ; and on the top of the hill follow 

 the marly beds with Exogyra virgida in lumachelles, and Phola- 

 domya acuticosta. If any Pterocerian is to be made out here, it 

 must be by a very close examination of fossils, which are not by any 

 means abundant. 



At the forges of Donjeux, about a mile further on, is a quarry in 

 which the oolite of La Mothe is supposed to be seen. Here the top 

 beds consist of the irregular Astartian limestones ; and the base of 

 the quarry is worked for massive rocks, which are on the whole 

 compact, varying on the one hand to lithographic stones, or on the 

 other developing a fair proportion of oolitic grains, but totally un- 

 like the Diceras-beds, because like any other semioolitic rock. Here, 

 then, is no repetition ; and on the whole, with the exception of 

 the remarkable Diceras-beds, the succession in this valley is very 

 similar to, and certainly consonant with, what we saw in the last 

 section in the Meuse department. The chief noticeable point is that 

 the peculiar pisolitic character is exhibited rather at the base than 

 towards the top of the mass. 



Pig. 6.— Map of Part of the Marne Valley. (Scale 1 : 80,000.) 



Now let us pass to the valley of the Marne. A complete section 

 of the lower portion may be obtained by following the right bank 

 of the river from Youecourt to Buxieres, and then mounting the 



