40 THE OLIGOCENE BEDS 



between these two horizons, but French geologists are not in 

 accord as to their exact relations. We have no space to enter 

 into this matter, but the following works may be consulted with 

 advantage — Dollfus, Bull. Soc. Geol. Fr., 3e. ser, t. vi. (1878), 

 p. 299, and observations thereon by MM. Cossmann and Lam- 

 bert, Afhn. Soc. Geol. Fr., 3e. ser., t. iii. (1884), p. 18. 



The Fontainebleau beds are almost unfossiliferous in the 

 vicinity of the town from which they derive their name, but in 

 the Etampes district they develop into the shelly sands, &c., as 

 we have already seen. Many French authors regard the whole of 

 these beds, including those of Jeurre and Morigny, as comprised in 

 the Fontainebleau beds, and allude to them collectively as the 

 " Sables de Fontainebleau et d' Etampes.'''' It is tolerably clear, 

 however, that the sandstone of Fontainebleau is on the same 

 horizon as that of Ormoy, near Etampes, presently to be des- 

 cribed. 



6. PEBBLY SANDS OF ETRECHY. 



These sands are unconformable to the beds beneath, and 

 sometimes repose directly on the molasse of Etrechy without the 

 intervention of the faluns of Jeurre and sands of Morigny. This 

 point is conclusively proved by the section of the falun at Brune- 

 haut, about half-way between Etrechy and Etampes. These 

 pebbly sands are a littoral deposit, being grey, fawn, or chamois 

 colored sands, with numerous flint pebbles. 



The following typical section* may be seen at the farm of 

 St. Phalier, near Jeurre : — 



Section at St. Phalier. 



ft. in. 



Vejrelable earth ....... about i 6 



Alternating^ yellow and brown sand .... 27 



Brown and argillaceous sands, with pebbles . . i 7 



Brown sand, ferruginous in parts, with pebbles, lying 



unevenly on bed below ..... 4 8 



Sands with large pebbles irregularly dispersed, un- 

 conformable to the underlying bed ... 33 



Sands of Morigny with Meretrix splendid a, developing 



from a mere thread-like bed into a thickness of . 3 3 



Red falun, with Axincva obcvata, visible ; . . . 13 



reposing on the falun of Jeurre a little further on . 



A little to the north of the section of St. Phalier, and about 

 120 yards from the sand-pit at Jeurre, another fine exposure of the 

 pebbly sands of Etrechy, may be seen. Here are found a large 

 number of the teeth of Lanina and Myliobatis, and ribs of Halithe- 

 riicm. 



Much information concerning this division of the Oligocene 

 will be found in the admirable work of M. Tournouer, Bull. Soc. 

 Geol. Fr , 3e. sir., t. vi. (1878), pp. 675, et sqq. 



Abridged from Cossm.-inn and I.amberl. o/i. cit., p. i3. 



