184 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 13, 



E. by S. 



stone and marble, of grey, yellowish, and occasionally pink colours, 

 which at Untersberg near Salzburg, around the valley of Gosau, and 

 at numerous other places, plunges under strata of impure limestone, 

 marl and sandstone, charged with fossils of the gault and chalk. In 

 the western parts of Savoy, however, it is more clearly divisible into 

 three zones than at the city of Neufchatel itself, and the diagram of 

 the Montague du Chat already given, explains the fact (see fig. 3). 



In another section west of Chambery, which I made in company 

 with the Canon Chamousset, the order of the strata is exhibited in 

 this diagram (fig. 5). The lowest rocks visible are the Oxfordian 



T.. - W. by N. 



Fig. 5. 



Tertiary. { ^ 



r b. 



Cretaceous. •< a* 



i a. 



1 &2. 



Marine molasse. 



Freshwater limestone and conglomerate. 

 Upper Neocomian (Chama ammonia), 

 Bliddle Neocomian (Spatangus retusus). 

 JiOwer Neocomian {Oyster bands). 

 Oxfordian Jura and coral rag limestone. 



limestones and shale, and the coralline limestone before adverted to 

 (Nos. 1 and 2) which constitute the uppermost Jurassic band of this 

 region. On this reposes the lowest neocomian («), which is a hard 

 siliceous limestone with small, sharp-plaited Ostrese, a small Terebra- 

 tula, Nerinaea, &c. The middle neocomian (a*) consists of alterna- 

 tions of bluish grey marly limestone and bands of green-grained calc 

 grit and beds of chert, and in this band most of the fossils occur, in- 

 cluding the very characteristic form Spatangus retusus. The upper 

 division {b) is a whitish limestone, often in a state of marble, which 

 in Savoy contains both Hippurites and the Chama {Caprotina) am- 

 monia (D'Orb.). 



For the most part, however, in its prolongation along the flanks of 

 the Savoy, and particularly in the Swiss Alps, the neocomian is divi- 

 sible into two great subformations only ; the lower being dark- 

 coloured and marked by the Gryphcea Couloni (Leym.), Rhynconella 

 (Terebratida) depressa (D'Orb.), and Spatangus retusus (Lamk.) 

 (Spatangus-kalk, Studer), and the upper being a light-coloured hme- 

 stone containing the Caprotina ammonia (the Schratten-kalk of 

 Escher), is a sure and excellent horizon throughout the greater part 

 of the Alpsf. 



Cretaceous Greensand or Gault of the Alps. {Turriliten-Etagef 

 Escher.) — The largely exposed neocomian limestone of the Savoy Alps 

 supports, as above stated, in various escarpments, a thin zone of 

 dark-coloured marly limestone, occasionally freckled with grains of 

 chlorite, and abounding in fossils. In a collection made by my 

 guide, Auguste Balmat of Chamonix, at the Montague des Fis, Pro- 

 fessor Pictet of Geneva recognized Ammonites cristatus (De Luc) ; A, 

 Hugardianus (D'Orb.) ; A.Mayorianus (D'Orb.) ; A. injlatus (Sow.) ; 



t It is worthy of note, that this upper band, as distinguished by the Caprotina 

 ammonia, is absent at Neufchatel, as well as the lower part of the formation. 



