JURASSIC OF THE PARIS BASIN, 



531 



The lower portion of the Oxfordian is not brought into this scheme, 

 the last subdivision being in another scheme made the base of the 

 Corallian. 



Two river-valleys cross this district, and the traverses made along 

 these give a complete idea of the development of the rocks under 

 consideration, which here attain their maximum in the lower part, 

 where they are truly marvellous. 



Fig. 9. — Map of the Valley of the Armando n, south of Tonnerre. 

 (Scale 1 : 80,000.) 



We commence with the valley of the Armancon. At Ancy-le-Franc 

 an admirable section commencing in true Oxfordian rocks is seen 

 above the church. Towards the base are marly beds, with only an 



2n2 



